toward market transformation: commercial heat pump water
TRANSCRIPT
TOWARD MARKET TRANSFORMATION: COMMERCIAL HEAT PUMP WATER HEATERS
FOR THE NEW YORK ENERGY $MARTSM REGION Final Report
Prepared for
THE NEW YORK STATE ENERGY RESEARCH AND DEVELOPMENT AUTHORITY
Albany, NY
Laurie Kokkinides Project Manager
Prepared by
AMERICAN COUNCIL FOR AN ENERGY-EFFICIENT ECONOMY Washington, DC
Harvey M. Sachs, Ph.D.
Project Manager
Agreement 6299
NYSERDA October 2002
NOTICE
This report was prepared by the American Council for an Energy-Efficient Economy in the course of
performing work contracted for and sponsored by the New York State Energy Research and Development
Authority (hereafter “NYSERDA”). The opinions express in this report do not necessarily reflect those of
NYSERDA or the State of New York, and reference to any specific product, service, process, or method
does not constitute an implied or expressed recommendation or endorsement of it. Further, NYSERDA, the
State of New York, and the contractor make no warranties or representations, expressed or implied, as to
the fitness for particular purpose or merchantability of any product, apparatus, or service, or the usefulness,
completeness, or accuracy of any processes, methods, or other information contained, described, disclosed,
or referred to in this report. NYSERDA, the State of New York, and the contractor make no representation
that the use of any product, apparatus, process, method, or other information will not infringe privately
owned rights and will assume no liability for any loss, injury, or damage resulting from, or occurring in
connection with, the use of information contained, described, disclosed, or referred to in this report.
ABSTRACT
Water heating is the fourth largest energy user in the commercial buildings sector, after heating, air
conditioning, and lighting. For many building types (such as full-service restaurants, and motels and
hotels), water heating is a major energy user. Heat pump water heaters (HPWHs) promise both improved
efficiency and air conditioning benefits. Because HPWHs have very low market share, ACEEE studied
market transformation for the New York State Energy Research and Development Authority (NYSERDA).
The work included extensive interviewing to choose the most attractive market sectors and the most
important market barriers; developing a rating method procedure, installation sizing methods, and a case
study (based on monitoring data and simulation) of a large installation to reduce barriers.
ACEEE recommends that NYSERDA consider additional work on HPWHs. NYSERDA should focus on
one market segment, support early field installations with performance monitoring, consider collaborating
with an in-state manufacturer, exploit the case studies from the monitored sites, and consider using
financial incentives (particularly for middle-market actors).
After the project was launched, the number of manufacturers declined substantially, and there seems to be
virtually no sales infrastructure left in New York State today. However, this project’s identification of
priority market segments and significant barriers will help the market grow when new opportunities arise.
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ACKNOWLEDGMENTS
The project described in this report resulted from a NYSERDA competitive solicitation, Program
Opportunity Notice 500-99. The award was made to Sachs & Sachs, Inc, of McLean, Virginia. Shaping the
final statement of work and schedule was managed by Matt C. Brown of NYSERDA, whom we thank for
his careful attention to detail. Early in 2001, Harvey Sachs, a principal of Sachs & Sachs, Inc., was named
the Director of Buildings Programs for the American Council for an Energy-Efficient Economy,
Washington, D.C. For NYSERDA, Project Manager Laurie Kokkinides arranged transfer of the contract to
ACEEE, and continued to manage the contract. At ACEEE, Elizabeth Brown and Kalon Scott assisted with
research; Renee Nida edited and formatted the manuscript; and Executive Director Steven Nadel reviewed
the draft final report; we thank all for their assistance.
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TABLE OF CONTENTS Section Page
SUMMARY ................................................................................................................................................... 1 1 INTRODUCTION............................................................................................................................ 1
Background................................................................................................................................... 2 Goals............................................................................................................................................. 4 Project Summary .......................................................................................................................... 4 Findings ........................................................................................................................................ 5 Summary of Recommendations.................................................................................................... 7
2 METHODS AND RESULTS .......................................................................................................... 9
Identification of the Most Attractive Market Segments................................................................ 9 Literature Resources ..................................................................................................................... 9 Interviewing Experts..................................................................................................................... 9 Building an Options Spreadsheet................................................................................................ 10
Establishing Information Resources for Customers ................................................................... 18 Results: Information Resources.................................................................................................. 19
Establishing Industry Standards ................................................................................................. 19 Field Study.................................................................................................................................. 20
Results of the Field Study........................................................................................................... 21 Developing Technical Tools....................................................................................................... 23
3 IMPACTS FOR NEW YORK STATE.......................................................................................... 25
Market Transformation Impacts in New York State................................................................... 26 4 DISCUSSION ................................................................................................................................ 29
Major Findings ........................................................................................................................... 29 Project Success and Failures....................................................................................................... 30 Recommendations ...................................................................................................................... 30 Conclusions ................................................................................................................................ 32
REFERENCES............................................................................................................................................. 33 APPENDIX 1: An Annotated Bibliography on Commercial-Scale Heat Pump Water Heatsr..................... 35 APPENDIX 2: Survey Instrument................................................................................................................ 39
Market Segmentation Terms Used ........................................................................................................... 39 ACEEE/NYSERDA Commercial Heat Pump Water Heater Project Interview Record........................... 40 Discussion of the Interview Instrument.................................................................................................... 44
APPENDIX 3: List of Industry Interviewees ............................................................................................... 47 APPENDIX 4: Options Sreadsheet for Assigning Priorities to Market Segments, with Discussion............ 49 APPENDIX 5: HPWHs and Peak Electricity Demand ................................................................................ 57 APPENDIX 6: 2002 Performance Standard Language ................................................................................ 59 APPENDIX 7: Available Performance Data for Commercial HPWHs ....................................................... 67 APPENDIX 8: Monitoring and Simulation Results from the Geneva Lakefront Hotel ............................. 673
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SUMMARY
Water heating is the fourth largest energy user in the commercial buildings sector, after heating, air
conditioning, and lighting. Water heating is a major energy user in building types such as full-service (sit-
down) restaurants, motels and hotels, assisted living centers, and other facilities that do a great deal of
laundry or dishwashing.
Heat pump water heaters (HPWHs) are a promising technology. HPWHs use the same mechanical
principles as refrigerators and air conditioners. While refrigerators remove heat from the interior and
discharge it to the (kitchen) environment, HPWHs take heat from the environment and concentrate it to
heat water for service needs. HPWHs typically provide about 2.5 times as much heating per kilowatt-hour
(kWh) of electricity as resistance water heaters. Counting the energy used at the power plant to produce the
electricity for the heat pump, HPWHs can be more efficient than conventional natural gas water heaters. By
taking heat out of the room, they also provide spot cooling and dehumidification.
Despite such opportunities for heat pump water heaters, the present commercial market is very small—
perhaps not as large as 1000 units/year nationally. For the entire United States, including both residential
and commercial applications, the total number of units shipped was probably only a few thousand. This
compares with approximately three million each for electric resistance and gas water heaters
(predominantly with storage volumes less than 120 gallons, with about 90% of sales thought to be for
residential applications).
Because of the energy savings potential and economic advantages for New York State, the gap between
potential and reality is an opportunity. A focus on the market segments in which the potential is greatest
would support market transformation in these niches. In turn, profits from sales to these markets would
give the cash flow for attacking other, larger niches. Thus, the goal of the present study is to discover the
elements and paths required for market transformation, for making commercial heat pump water heaters an
easy choice for situations where their use would save money and energy. The project had the following
discrete objectives:
1. To identify the most compelling particular market segments and end-use applications for the
application of commercial heat pump water heaters in New York State.
2. To identify key barriers to greater acceptance of the technology for these applications.
3. To develop elements of the missing infrastructure that would encourage decision-makers to
feel comfortable choosing HPWHs. These elements include a rating method procedure,
installation-sizing methods, and a detailed case study.
S-1
The first task was a survey of industry experts. This effort led to an Options Spreadsheet that identifies the
most promising market segments based on the insights of the industry experts interviewed. The sheet is
populated with New York State-specific data on the size of potential markets.
Second, to document the cost-effectiveness of commercial HPWH systems and to optimize system
performance to improve design for other facilities, a project subcontractor monitored the performance of a
large HPWH system (40 tons) installed in a hotel in Geneva, N.Y. The detailed data allowed simulation of
performance with air-source HPWHs in upstate and downstate locations. This facilitates understanding of
sizing issues and documentation of spot cooling benefits.
The third component was developing and providing support tools for the design and sales process. These
included a performance standard to be used in conjunction with an American Society of Heating,
Refrigeration, and Air-conditioning Engineers (ASHRAE) test method in order to simplify specifications.
This was complemented by the development of a sizing tool, a spreadsheet that allows middle-market
participants to choose the best possible combination of heat pump capacity and storage capacity for a mix
of hot water and air conditioning needs (which may not be simultaneous).
ACEEE recommends that NYSERDA consider ways to encourage greater use of HPWHs. Success will
require both time and investment, but the great energy savings potential for customers may make it
worthwhile. ACEEE proposes the following course of action:
• Select and focus on one market segment. ACEEE recommends full-service restaurants, which
were most highly ranked by our interviewees.
• Put 5–10 heat pump water heaters into full-service restaurants (where natural gas is not
available) and monitor the results. Consider making the installation free to selected
participants in return for the right to monitor energy and water use, and meals served. Build
both engineering studies and marketing materials by documenting the exemplary installations. • Consider collaborating with an in-state manufacturer. ECR International has developed a
residential HPWH that may be suitable for smaller restaurants and may be interested in
providing prototypes of a larger commercial design. This would be a logical step between
NYSERDA research and market transformation activities.
• Exploit the case studies from the monitored sites. With the case studies, information on the
web site, manufacturers’ materials, and other literature, a “circuit rider” could carry the story
to the industry’s meetings and stakeholders. • Consider using financial incentives for the first hundred or so installations in order to give
business owners reasons to want to try the technology. Design assistance, training, or even
S-2
incentives to middle-market participants might be as effective in this market as direct
incentives to purchasers.
• Back out. After two years or so of incentives, ramp them down in order to expose the market
to some discipline.
The current project successfully identified high-potential market segments for early adoption of HPWHs,
documented barriers, and developed support tools and information. However, this project did not increase
the sales or installation rates for commercial HPWHs in New York State. In retrospect, while the project
was under way, the number of HPWH manufacturers declined substantially. There seems to be virtually no
sales infrastructure for commercial-scale HPWHs left in New York State today.
S-3
S-4
Section 1
INTRODUCTION
Water heating is the fourth largest energy user in the commercial buildings sector, after heating, air
conditioning, and lighting (DOE 2002). There are many building types for which water heating is a major
energy user. These include full-service (sit-down) restaurants, motels and hotels, assisted living centers,
and other facilities that do a great deal of laundry or dishwashing. On the other hand, for some buildings
(such as offices), water heating can be relatively minor.
Although conventional natural gas systems are not particularly efficient, the generally low cost of gas gives
them predominance where natural gas service is available. Where gas in not available, water heating is
done with oil, propane, or electricity. In most cases, electric resistance water heating is the technology of
last resort because of its cost.1 Conversion of electricity to heated water is almost 100% efficient in terms of
site energy. However, generating and distributing electricity generally uses about three times as much
energy as is delivered to the site where it is converted to heat. Thus, the source or “primary” energy use for
resistance water heating is very high. Because of this, electricity is much more expensive than natural gas,
per unit of site energy. Correcting for both the low fuel conversion efficiency for electricity at the
generating plant and the relatively low efficiency of gas water heaters, electric resistance heating is
typically about twice as expensive as natural gas heating, which is why the latter is preferred.
Heat pump water heaters are a promising “electro-technology” alternative to resistance water heating.
HPWHs use the same mechanical principles as refrigerators and air conditioners. While refrigerator remove
heat from the interior and discharge it to the (kitchen) environment, the HPWHs take heat from the
environment (from the indoor environment, or occasionally from the outdoors) and concentrate it to heat
water for service needs. The underlying technology is straightforward, using the same compressors as
heating, ventilating, and air conditioning (HVAC) equipment. As tested in the laboratory, HPWHs typically
do about 2.5 times as much heating as resistance water heaters.2 Indeed, counting the energy used at the
power plant to produce the electricity for the heat pump, HPWHs can be more efficient than conventional,
atmospherically vented natural gas water heaters.
In addition, many commercial situations require water heating and spot cooling of work areas at the same
time. Some examples include commercial laundries, linen services, and restaurant/food service kitchens.
The heat and humidity in these areas often makes work extremely unpleasant, leading to low productivity
1 In some buildings, resistance electric units are chosen for low first cost. They are also chosen where
building features preclude the flues required by fossil-fired water heaters
1
and high employee turnover. HPWHs provide spot cooling by extracting heat from the surrounding space.
Despite such obvious matches for HPWHs, the present commercial market is very small—perhaps not as
large as 1000 units/year nationally. As an indication of market potential, there are an estimated 19,000
restaurants in New York alone. If only 10% of them used electrically heated hot water, converting them to
HPWHs would require roughly the entire U.S. manufacture of these products for a year.
BACKGROUND
Nationally, the predominant energy sources for commercial building water heating are natural gas and
electricity; propane and oil have much lower shares (DOE 2002). In the Northeast, among all non-
residential buildings, electricity and natural gas have roughly equal market shares (see Table 1). However,
the market share of electric and gas water heating varies greatly with building type. Food services and
lodging are two of the building types with high water heating intensity (water heating is a larger fraction of
energy use and building operating expenses). High energy use and high costs for heating water make these
building types attractive targets for HPWHs, where efficiency promises reduced life-cycle costs.
Interestingly, in these market segments, natural gas has approximately twice the market share of electricity.
Table 1. Electricity as Primary Water Heating Source for Commercial Buildings, Food Service Buildings, and Lodgings (Hotels, Motels, etc.) .*
Northeast Buildings with Electric Water Heating (1000s)
Electricity Natural Gas % Electric
All Buildings 1,546 1,520 50%
Food Service 90 223 29%
Lodging 46 86 35%
* U.S. Department of Energy. 2002. Buildings Energy Databook: 1.3 Commercial Sector Energy
Consumption. Table B-25.
http://buildingsdatabook.eren.doe.gov/frame.asp?p=/chapterdisplaymain.asp?ChapterID=1.
Washington, D.C. U.S. Department of Energy.
HPWHs have very low market penetration. For the entire United States, including both residential and
commercial applications, the total number of units shipped was much less than 10,000 in 2001. It was
probably only 1000–2000.3 This compares with approximately three million each for electric resistance and
2 This is strictly true only if extracting heat from the environment is “free” or valued. This is the case
when building or area heat loads require air conditioning all or most of the time, as in the next paragraph. 3 Estimate developed based on discussions with manufacturers and other market actors.
2
gas water heaters4 (predominantly with storage volumes less than 120 gallons, with about 90% of sales
thought to be for residential applications).
Today’s prices for commercial HPWHs are higher than would be expected from a manufacturing cost
analysis focusing on the units themselves. The reasons are clear. Because few units are sold, the price of
each unit has to cover relatively high engineering, assembly, and overhead costs. It also must cover the
costs of training and support for the small numbers of contractors who sell, install, and service HPWHs.
Low cash flow precludes efforts to systematically improve awareness of HPWHs and their benefits to
decision-makers. In addition, high purchase prices discourage customers, even when the life-cycle cost is
lower than for any competing way to heat water for their businesses. Furthermore, many commercial
situations require water heating and spot cooling of work areas at the same time (as discussed above).
Because of the potential for energy savings and economic advantages for New York State, the contrast
between potential and reality is an opportunity; if we would focus on the market segments in which the
potential is greatest, then we would assist in market transformation in these niches. In turn, profits from
sales to these markets would give the cash flow for attacking other, larger, niches. Iteratively, and hopefully
without need for additional public support, this would lead to market transformation (the acceptance of
cost-effective commercial-scale products, in this case HPWHs to provide heating services for businesses).
Of particular interest is the contrast between “mature” or “mainstream” products and “emerging” products
in the former’s projection of a mature infrastructure to market actors, both customers and key middle-
market decision-influencers. As pointed out by Moore (1999),5 mainstream products are fully supported by
an infrastructure that lowers the cost of choosing the product and decreases risks associated with specifying
it. Some parts of this infrastructure are physical assets, such as inventory in a warehouse that reduces the
perceived risk of product installation delays. People are even more important in this infrastructure. One
aspect is contractor confidence that the technology works and does not require costly call-backs that can
jeopardize customer relationships that have been nurtured for years. The infrastructure also includes
knowledgeable advocates who make the sales, experienced technicians who install and maintain the
equipment, and satisfied owners who spread the word to colleagues and even to competitors. Developing
this infrastructure generally takes years and many satisfactory installations.
Other infrastructure components, while costly in the framework of an emerging business with very limited
cash flow, are easier to provide. Examples include:
4 Gas water heater certification programs include propane; units are differentiated by model numbers.
Oil-fired water heaters are much less common. 5 See particularly the discussion of “whole product planning, starting p. 112.
3
• Engineering case studies that give confidence that the technology can be installed and deliver
value to customers.
• Impartial sizing methods and other software tools that help contractors and design engineers
choose the right combination of parameters (such as HPWH capacity and hot water storage
capacity to best balance first costs, operating costs, and user needs for both hot water and
cooling).
• Web presence that serves as a hub for information for the industry at large. The existence of a
web site with independent information would add credibility to efforts to market an emerging
technology.
GOALS
With this background, the goal of the present study is to discover the elements and paths required for
market transformation. By this we mean making commercial HPWHs an easy choice for situations where
their use would save money and energy. To achieve this goal, the project had several discrete objectives:
1. To identify the particular market segments and end-use applications for which the most
compelling case can be made for the application of commercial HPWHs in New York State.
2. To identify key barriers to greater acceptance of the technology for the most highly ranked
market segments.
3. To develop elements of the missing infrastructure in order to encourage decision-makers and -
influencers to feel comfortable choosing HPWH. These elements include a rating method
procedure, installation sizing methods, and a case study of a large installation.
PROJECT SUMMARY
The first task was a survey of industry experts. The interviews were designed to pool the experts’ wisdom
and knowledge in order to determine the most promising markets for HPWHs and to identify the most
significant barriers to their application. This effort led to an Options Spreadsheet that identifies the most
promising market segments based on the insights of the industry experts interviewed. The sheet is
populated with New York State-specific data on the size of potential markets. The experts’ assumptions
guided the rest of this project. However, the Options Spreadsheet is also a tool that allows program
designers to quickly identify the other promising market segments and to carry out “what-if” analyses to
evaluate alternative assumptions from those of the interviewees.
Next, to document the cost-effectiveness of commercial HPWHs and to optimize system performance to
improve design for other facilities, a project subcontractor monitored the performance of a large HPWH
4
system (40 tons, or 480,000 British thermal units [Btus]) installed in a hotel in Geneva, N.Y. The
installation chosen was the only commercial HPWH installation identified in New York State, an indication
of the immaturity of the market today. The hotel actually uses water-source heat pumps instead of the air-
source units that are thought to be the major market opportunity. The data generated from March–May
2002, were very detailed, and allowed simulation of performance with air-source units, if they were
substituted in this hotel. This facilitates understanding of sizing issues and documentation of spot cooling
(air conditioning) benefits.
Another important component was developing and providing support tools for the design and sales process.
One part of this was developing a performance standard to be used in conjunction with an ASHRAE test
method. Adoption of a performance standard can simplify specifications. It is an important part of helping
new technologies become mainstream applications. This was complemented by the development of a sizing
tool, a spreadsheet that allows middle-market participants (designers, vendors, etc.) to choose the best
possible combination of heat pump capacity and storage capacity for a mix of hot water and air
conditioning needs (which may not be simultaneous).
FINDINGS
ACEEE draws the following conclusions from this study.
1. There is large technical and economic potential for energy savings by using HPWHs to
replace resistive water heating in commercial installations in New York State. For example,
29% of food service buildings and 35% of lodgings in the Northeast used electricity as the
primary water heating energy source. Each could save about 60% of its water heating bill with
a well-designed heat pump water heating system. The effect on peak demand is likely to be
small—it has not been directly estimated. Doing so would require detailed assumptions about
water use and cooling needs in each class of business. For example, if hotel laundries
primarily operate during day shifts, there would be greater peak reduction than if they
primarily run on a night shift.
2. The highest priority market segments are (in order of declining estimated attractiveness):
• Full-service restaurants—dishwashing, food preparation, wash-down, and lavatories;
• Health care and assisted living facilities, beginning with kitchen and laundry uses;
• Coin-operated laundries;
• Larger-scale commercial laundries and linen services,
5
• Hotel and motel applications, ranging from laundries to restaurant kitchens, pools,
and guest services;
• K-12 schools, starting with food service and possibly including other applications
(lavatories, labs, locker rooms, or pools);
• Health clubs, including locker room, hot tub, and indoor pool uses; and
• Fast food restaurants: primarily for washdown and secondarily for lavatories.
Other applications were considered less attractive for various reasons discussed in the
text. They included prisons, college dormitories, and highway rest areas.
3. Across all applications, the key market barriers most often identified by industry experts were
• Low awareness of the technology among customers, specifiers, and the trades. Too few
people know that HPWHs can meet needs better than conventional alternatives in many
applications.
• The first cost premium for HPWHs relative to conventional water heaters (or boilers) is
perceived as too high. This has the following factual and perceptual components:
• Objectively, the price premium reflects actual costs of an emerging technology and
its infrastructure. Each unit sold carries a higher burden of development,
certification, marketing, and corporate overhead costs than mass-produced products.
• In addition, the perception of high costs (and the discounting of life-cycle savings)
reflects a business bias toward putting capital into core aspects of the business
instead of areas considered more peripheral. Managers are more likely to invest in
areas they know than in less-visible “utility” infrastructure. In addition, when capital
is rationed, life-cycle cost considerations are less important to decision-makers than
first costs.
4. Where public policy objectives, such as increased energy efficiency, provide a rationale for
intervention, market transformation has been quite successful for many technologies (such as
compact fluorescent lights and condensing furnaces). One component (possibly required for
HPWHs) is using financial incentives to address awareness and first cost issues.
5. Detailed performance monitoring of a commercial kitchen whose hot water needs are met by
HPWHs documented that the internal loads of the kitchen (lights, stoves, heat rejected by
refrigerators and freezers, etc.) are large. Space heating was required only 168 hours during
the winter of 2001–2002. Thus, HPWHs that extract heat from the kitchen will rarely lead to
additional heat being required and will generally provide low-cost air conditioning. In
6
addition, for the full-service restaurant in Geneva, N.Y. that served meals from breakfast
through supper, the water use was rather constant throughout the day (which tends to
minimize storage requirements). The monitoring provided data that allowed simulation
(modeling) of kitchen water heating and space conditioning needs. This model evaluated the
performance and economics of an air-source system that could be installed either upstate
(Rochester) or downstate (New York City) to meet the loads characteristic of this commercial
kitchen.
6. This project was premised on the assumption that HPWHs, like many other emerging
technologies, might diffuse more readily from the commercial to the residential sector since
larger commercial jobs generally can support more custom treatment in design and
installation. To our surprise, there seems to be some minimum level of market share that is
required before market transformation can aspire to success. Since the project began,
additional manufacturers have exited the commercial-scale HPWH market and there are
virtually no contractors who seem at all interested in the technology.6 The only region in
which there are significant sales of commercial products seems to be Hawaii, where the
combination of very high energy prices and a moderate climate that allows heat to be
extracted from the outside air year-around has supported sales and infrastructure
development.
SUMMARY OF RECOMMENDATIONS
Based on the results of this project, ACEEE recommends that NYSERDA consider ways to encourage
greater use of this promising technology. Success will require both time and investment, but the great
energy savings potential for customers may make it worthwhile. ACEEE proposes that NYSERDA (1)
select and focus on one market segment: the goal is to develop allies among the users and vendors who
serve a particular segment, so the word can be spread credibly by its market participants. We recommend
full-service restaurants. (2) Put 5–10 HPWHs into full-service restaurants and monitor the results. Use
these for effective case studies. (3) Consider collaborating with an in-state manufacturer. This would be a
logical step in NYSERDA support for the evolution of the industry and would bridge the gap between
NYSERDA research and market transformation activities. (4) Exploit the case studies from the monitored
sites. With the information on the web site, manufacturers’ materials, and other literature, a “circuit rider”
could carry the story to the industry’s meetings (as talks and exhibits) and to franchisers and owners of
6 Of 14 manufacturers listed by FEMP (2002), several (including DEC) have left the market during the
course of this project. Several others are niche vendors who may build to order. With the exception of Colmac and the successor to AER-ETech, there may be no production manufacturers in the United States today.
7
multiple restaurants, etc. (5) Consider using financial incentives to buy down the incremental cost of design
and purchase for the first hundred or so installations in order to give all parties reasons to want to try the
technology. Finally, back out. After two years or so of buy-downs, ramp down the incentives in order to
expose the market to some discipline.
These recommendations are more fully developed in the “Discussion” section of this report.
8
Section 2
METHODS AND RESULTS
IDENTIFICATION OF THE MOST ATTRACTIVE MARKET SEGMENTS7
Three distinct subtasks comprised this phase of the project. The first was an industry study that began early
in 1998. It included participating in industry meetings, developing programs, and listening to the concerns
of practitioners. It also included observing short courses offered by Dr. Carl Hiller, formerly of the Electric
Power Research Institute (EPRI) and Mr. Alan Shedd, P.E., of Jackson EMC. The second subtask was a
review of all accessible literature prepared by EPRI, ASHRAE, and other organizations; a bibliography is
attached (see Appendix 1). In parallel with these tasks, a comprehensive survey instrument was developed,
tested, and trialed. Analysis of the 16 structured interviews of industry experts and leaders became the basis
for recommendations of the most attractive market segments and the most critical market barriers (Sachs
2002).
Literature Resources
The bibliography in Appendix 1 lists available documents dealing with commercial-scale HPWHs. Some
are accessible via the World Wide Web, and are so identified. Important categories include technology
assessments, applications handbooks, case studies and similar materials, short course materials, internal
reviews by utilities and others, and standards documents giving test and rating methods. In general, these
documents focus on the technology and its application from a technical perspective. This is different from
an attempt to understand the markets and the barriers to the technology (which is the focus of the present
report). This bibliography is available through the ACEEE/NYSERDA commercial HPWH web site
(http://aceee.org/buildings/coml_equp/hpwh/index.htm); for more information, see below.
Interviewing Experts
The core of this project phase was interviewing industry experts and analyzing their responses to an
extensive set of questions. The survey instrument was developed, tested, and then trialed with Chris Reohr8
of NYSERDA before being used. Appendix 2 presents the survey instrument. Sixteen industry experts
participated (separately) in the structured interviews. The interviewees and their interests are listed in
Appendix 3 and summarized in Table 2.
7 This section is largely adapted from Sachs (2002). 8 Chris graciously consented to a “practice interview” in which he pretended to be an industry expert to
help remove ambiguities and otherwise improve the survey instrument.
9
Table 2. Interviewees and Affiliations Summary. Industry Number
Manufacturers of HPWHs 7
Research managers, non-manufacturer 3
Utility marketing 3
Installation specifiers and designers 2
Other government (building codes) 1
The original project objective was to interview 25 industry participants. However, only 18 candidates were
identified and all but two of these were interviewed.9 The interviewees included manufacturers, designers,
research managers, marketers, specifiers, and others. The one group that is missing from this tabulation is
owners: managers or owners of facilities with commercial HPWHs. Except for the field study described in
the next section of this report, no appropriate New York installations were found.
The interviewer took extensive notes during each telephone interview and compiled each in a standard
form. Each of these was then sequentially folded into a compilation of interview results. Interviewee
rankings (segments and barriers) were compiled quantitatively and all comments and suggestions were
compiled as text for synthesis. These data, stripped of information that would identify the source of any
particular statement, were a basic input to the subsequent analyses designed to build an Options
Spreadsheet.
Building an Options Spreadsheet
A tool was needed to combine data from the interviews and other key information in a form that would
allow program designers to select the highest-priority market segments for early transformation programs.
In addition to the interview information, the second kind of key data includes the load characteristics (the
match between water heating and space air conditioning requirements) and the flatness (constancy) of the
load through the day. Finally, the Options Spreadsheet requires information about the size of the market in
New York State, as represented by the number of installations of each type in the State now.
The output of this exercise is shown in Table 3 for the most highly rated market segments from this phase
of the study. The full sheet and its explanation are given in Appendix 4. To summarize, the principal rows
name and describe a discrete market segment (sub-industry) and an application in it, such as the
dishwashing application in the full-service restaurant segment. Two rows are weighting factors for the
column parameters in order to allow policy analysts to re-weight the variables. Columns include
10
“Evaluations,” rank by interviewees, load characteristics, and the size of the potential market. “Load
Characteristics” and ”Load “Flatness” are defined above. “Coincidence” estimates the extent to which air
conditioning and water heating loads occur together. For HPWHs, the best applications need nearly
constant hot water and spot air conditioning, simultaneously. The last columns in this group estimate the
installation potential in New York State for that particular use.10
Table 3. Options Spreadsheet, Showing Highest-Rated Market Segments
to Illustrate Structure.11 Evaluations Load Characteristics
Market Segments
or End Uses
Auxiliary Uses
Proposed Rank Score
Ranked by
Inter-views
Flat-ness12
HW–A/C Coinci-dence13
NY Potential Install-ations
Log of NY
Potential
Install-ations
Parameter Weight 1 1 1 1 1 Maximum Possible
Score 3 3 3 3 3
Full-Service Restaurant
Dish Washing 1 11.3 3 2 2 19,087 4.3
Full-Service Restaurant
Food Prep,
Cleaning Lavatory 1 10.3 3 1 2 19,087 4.3
Health Care, Assisted
Living Laundry 2 11.5 3 2 3 3487 3.5
Health Care, Assisted
Living
Food Prep,
Cleaning Lavatory 2 11.5 3 2 3 3487 3.5
For a particular water heating application, the score is calculated by a formula that includes modified values
of the four decision parameters: rank by the interviewees; judgment of load flatness; judgment of
9 We were unable to arrange interviews with two experts. One was a semi-retired research engineer
who had developed materials for EPRI but we were able to interview his co-author. We were also unable to formally interview one utility expert who was in the process of retiring.
10 The values used in the computations are those of Column J, the logarithm of the potential number of installations in Column I. This weights equal proportions equally, rather than equal differences. From a pragmatic perspective, this is appropriate: the difference for program selection and design purposes between 500 and 1000 potential installations may be as important as the difference between 19,000 and 20,000 installations.
11 See Appendix 4 for details. 12 The more hours per day that the application calls for water heating, the smaller the required storage
for a given heat pump capacity. Flatter loads can be met more economically. 13 An example might be a restaurant kitchen dishwashing station, where the air conditioning and
dehumidification will be valued whenever dishwashing needs hot water. Poor coincidence (and in this case, poor load flatness) would be represented by a kitchen that only used hot water for hand-washing (small amounts) and daily wash-down (large amounts). The kitchen might need 14-hour cooling in the cooking area, but use the vast majority of its water during a single hour.
11
coincidence of hot water and air conditioning demand; and an estimate of the number of potential
installations in New York State. However, the structure of the Options Spreadsheet allows NYSERDA or
others to alter weighting factors to aid in further evaluation or decision-making. The formula is specified in
this indirect way to allow analysts to re-rank applications by carrying out “what-if” exercises. NYSERDA
elected to use the default weighting factors selected by ACEEE. The value of the Options Spreadsheet is
that it systematically ranks market opportunities, as discussed below.
Result 1: Ranking Market Opportunities. The Options Spreadsheet (Appendix 4) presents the criteria
developed to aid the contractor and NYSERDA in prioritizing industries and their market segments. The
criteria are estimations of the potential and effort required for the contractor and NYSERDA to help market
transformation take place. This includes judgments by the investigator, ranking by interviewees, load
characteristics, and an estimate of the number of opportunities in New York State.
Based on the Option Spreadsheet analysis, ACEEE concludes that the following priorities would be
appropriate for New York State, in order from most to least attractive.
1. Full-service restaurants (without natural gas service). If 15% of full-service restaurants do
not have natural gas service, this is a market of almost 3000 relatively homogeneous targets
with excellent economics and strong motivation to install spot cooling for dishwashing and
other areas. Although we have focused on dishwashing as an application, these facilities also
use substantial hot water for food preparation and smaller quantities for lavatory service.
2. Health care and assisted living. An unknown fraction of these facilities, primarily rural, is not
served with natural gas. The combination of food service needs and patient care needs
suggests applicability of HPWHs in the kitchens and patient wings. In the latter application,
outside evaporators may be required for winter use.
3. Coin-operated laundries. There is a wealth of experience, primarily in the Southeast, with
HPWHs in laundry service. The “coolth” is a valued customer amenity. In New York State,
the economics are likely to be rather attractive. Where natural gas is available, the HPWH will
be sized to meet cooling needs, and will serve as a preheater for the washing machine hot
water. Where natural gas service is not available, larger HPWHs will provide as much water
heating as the cooling load will tolerate.
4. Linen services. Large linen services (greater than 10,000 pounds/day) use enormous amounts
of hot water and tend to have uncomfortably hot and humid work spaces year-around.
Installation of enough heat pump water heating capability to assure worker comfort will offset
some water heating load. Although the technology is not known to be widely used, the
fraction of water heating provided by heat pumps could be substantial if two other tricks were
applied: gray water heat recovery to the incoming stream of cold water; and maximum heat
12
extraction from the waste water with a refrigerant-to-waste water evaporator. This can safely
cool the waste water to 40°F.
5. Hotels/motels. At least one New York State hotel meets all its service water, restaurant, and
indoor pool water heating needs with 40 tons of HPWH capacity. It is, however, a special case
in which the water heaters extract heat from a ground-source heat pump “loop” or ground heat
exchanger. One benefit of this application has been to help cool the ground loop during the
summer, improving its efficiency and decreasing the field size required. Hotels and motels
will require more engineering than some other applications (e.g., restaurants) since the end-
uses are heterogeneous. The full-service application described above is one extreme. At the
other end, some hotel kitchens will install local HPWHs to relieve stress conditions in
dishwashing and other work areas.
6. K-12 Schools. Most schools seem to use central water heaters with distribution through a
pumped loop. The advantage of this “hotel loop” is that hot water is immediately available
where needed. The disadvantages are radiative losses from the hot water pipes and pumping
costs. Opportunities would include commercial-scale water heaters dedicated to support of
particular services, such as cafeteria or locker room loads. Another opportunity may be for
smaller HPWHs locally sited to serve lavatories, laboratories, and other classroom
applications. These units could be designed as heat recovery ventilators, extracting heat from
code-mandated toilet room ventilation.
7. Health clubs and similar applications. One elegant application is simultaneously heating hot
tubs and cooling/dehumidifying the air in those areas. This can be expanded to indoor pool
services (heating and dehumidification) or to locker room water and similar applications.
8. Fast-food restaurants have been debated extensively in the HPWH community. Where the
loads are restricted to washdown and lavatory service, there is poor coincidence between
cooling load and hot water load. This requires large hot water storage to balance needs, and
there is not always enough physical “real estate” for retrofitting the tank(s). Vendors have
been relatively unsuccessful in securing endorsement from franchisees or their central
organizations, so we consider it a relatively low priority.
Other applications considered included prisons, college dormitories, and highway rest areas. Each was
found less attractive as an early target. However, the spreadsheet is set up so NYSERDA staff and others
can easily play “what-if” games by changing the parameter weights assigned for any of the selection
criteria.
Identifying and Ranking Barriers. The next objective of this task was to analyze barriers to the adoption
of commercial HPWHs. This effort was based on questions in the industry interviews about primary market
barriers facing the technology. Based on their own experiences with different business challenges,
interviewees often ranked barriers differently. For example, manufacturers are less likely to consider high
13
purchase prices as a barrier than downstream market participants such as contractors who sell and install
equipment.
ACEEE undertook a systematic analysis of both quantitative and qualitative questions, with particular
attention to what interviewees said in response to the open-ended questions that invited broad-ranging
comments. The quantitative responses were tabulated to find central tendencies. The qualitative responses
were transcribed and sorted to have all responses to the same question grouped together so they could be
studied. From these analyses, fairly strong trends emerged about the most significant barriers. In the text
that follows, we name and describe each barrier. This is followed by ACEEE’s interpretation, in italics.
Across all applications, the most important market barriers identified by respondents were the following:
1. Not enough (customer, specifier, and trades) awareness of the technology: Few people know
that there is an opportunity to meet needs better with commercial HPWHs. In addition,
managers tend to be primarily focused on core product or service delivery. Too seldom do
they understand needs of workers for relief from high temperatures and humidity levels.
ACEEE Interpretation: Awareness is a key issue. However, experience of the Geothermal
Heat Pump Consortium strongly suggests that raising awareness raises expectations of
product availability. Newly aware customers become frustrated and negative when they
cannot find credible vendors if awareness increases more rapidly than product
availability and middle-market capability. As product becomes more available and better
supported, it will become appropriate to consider additional awareness efforts such as
industry-specific trade show participation for target segments such as commercial
restaurants.
2. The first cost premium for HPWHs relative to conventional water heaters (or boilers) is
perceived as too high. In part, this reflects the actual costs of an emerging technology and its
infrastructure. It also reflects the inability of advocates to develop a compelling value
proposition that includes all the benefits of HPWHs, including productivity related to air
conditioning at stressed work stations. Ironically, this problem is made harder because, in
many instances, the cost of water heating as a utility service is too little to warrant significant
attention by the owner or manager. Assume that water heating is 3% of the cost of operating a
restaurant. If one cuts that cost in half, the 1.5% saving goes straight to the bottom line of the
business. Intuitively, a 3% item might be thought to attract 3% of the manager’s attention
(perhaps 20–30 hr/yr), but an ancillary utility service is unlikely to get as much attention as
customer service, labor, and quality.
14
ACEEE Interpretation: Marketers have not been able to make a strong case for the value
of air conditioning benefits in work areas that are otherwise too hot and humid. The air
conditioning or spot cooling benefits are a byproduct of using air-source HPWHs. Again
using the results of the case study at the Geneva Lakefront Hotel (discussed in the “Field
Study” section, below) as an example, its restaurant kitchen requires heat very few hours
of the year. This means that there are few hours when an air-source HPWH would cause
the space to become too chilly, thus requiring heat. For the bulk of the operating hours,
an air-source heat pump system would make working conditions better by dehumidifying
and cooling the air at uncomfortable work stations, such as stoves and dish washing
areas. Unless managers are shown and value these benefits for improving productivity
and reducing turnover, HPWH systems will be undervalued, and thus seen as overpriced.
Sometimes, of course, HPWHs do not work as well as promised, which compromises their
reputation. The Geneva Lakefront Hotel illustrates this point. The measured performance
suggests that one of the four heat pumps may be performing poorly in a way that is not
obvious without careful technical work. For this reason or others, the cost of water heating
with this system is higher than with a natural gas system (because it extracts heat from a
ground loop used to air condition the hotel, this system does have ancillary benefits, not
accounted for, in improving the efficiency of the overall system at the hotel). The possibility
that some installations are not as good as they could be was not mentioned by any
interviewee.
3. Not enough credible, appropriate, third-party information on the technology. This relates to the
first barrier, lack of awareness.
ACEEE Interpretation: This is despite the effort of other third parties such as EPRI and the
Federal Energy Management Program (FEMP) that have commissioned and published some
outstanding reports and reviews (see Appendix 1). One of the goals of the present project has
been to increase the amount of credible, third-party information. In particular, the field study
at the Geneva Lakefront Hotel demonstrates how to build a case study that can be used by
manufacturers for training, and presented to clients. Also, the sizing method/spreadsheet
gives an easy-to-use method for “good-enough” sizing,14 and the performance-rating method
would allow manufacturers and advocates to proceed toward standards implementation.
4. Uncertainties about how to go to market with the equipment. The commercial market supports
a number of overlapping and competing delivery channels. Smaller equipment may be handled
14 EPRI published research-grade models that have not been widely adopted by contractors and
designers of typical, smaller systems for restaurants, schools, etc. The models are expensive and require more input data than generally can be made available.
15
by residential plumbing and heating contractors. Plumbing contractors have not been quick to
recommend heat pumps, which they may see as refrigeration equipment more than water
heaters. Mechanical contractors serving larger establishments could handle the technology, if
they knew about it and had seen it in action. For some jobs, they implement plans developed by
professional engineers. In other cases, they recommend equipment to the owner. Unless a
representative of the heat pump manufacturer “catches” the contractor or system designer at the
right time, the heat pump water heating option just will not be thought about due to the general
lack of awareness (Barrier 1). The manufacturer must provide his representatives with
persuasive materials so the decision-makers and -influencers are comfortable choosing the
HPWH option. These representatives may be much more comfortable with the “easy” sale of
the known product than risking their relationships with a “new” technology that may not meet
expectations—or may fail in the field.
ACEEE Interpretation: This problem is difficult for public interest market transformation
projects to address since it deals with varying business models adopted by different
manufacturers and their middle-market allies. In another NYSERDA project (dealing with
distribution transformers for commercial buildings), extensive outreach efforts by
contractors to all market segments may have modestly lifted awareness of the benefits of
energy-efficient transformers (Sachs and Smith Forthcoming).
5. “Early adopters are hard to find.” Conventional wisdom in the market transformation
community includes the idea that everyone wants to be early with a competitive advantage—
but very few want to assume the risks of being first. This is particularly true for “utility”
services like hot water, functions that are not perceived as part of the core functions of the
businesses that managers operate.
ACEEE Interpretation: Many market transformation programs, including some offered by
NYSERDA, have elected to offer financial incentives to compensate early adopters for the
perceived incremental risks they feel. In return, the sponsor of the incentives might insist
on the right to monitor hot water and electricity use.
Only when these needs are met do respondents mention information products, such as the
following.
6. Case studies. Case studies give owners and managers enough information to let them know
they are not the first, but are early enough to gain some competitive advantage. Since case
studies show successes, they tend to remove the risk of being an “early adopter,” thus
validating the technology—and the manufacturer, designer, or installer who is the source of the
information.
16
ACEEE Interpretation: The Geneva Lakefront Hotel case study provides useful data
(electricity and hot water use). Even more, it uses the data to show what is possible for other
installations, which can build confidence. It also calibrates the air conditioning benefits that
have been subject to much speculation.
7. Applications guidance (including software tools) to avoid sizing wrongly. Oversizing means first
costs that are unnecessarily high, which kills sales. Undersizing, particularly storage, risks running
out of hot water or paying too much for supplementary water heating services, such as resistance
electric elements.
ACEEE Interpretation: This project has led to the development of a sizing method that will be
made available to the industry through the ACEEE/NYSERDA web site
(http://aceee.org/buildings/coml_equp/hpwh/index.htm) without charge. It is unbiased with
respect to any manufacturer’s products.
8. Good articles in target market trade press outlets. Specialty magazines and tabloids are a key
vehicle for raising awareness. They may be more credible than a manufacturer’s own case studies.
Controlled circulation publications (free to industry participants) generally have small editorial
staffs and thus rely on industry sources for (free) submissions of articles, case studies, etc.
9. “Generic specifications” to help the owner specify what is actually needed.
Result 2: Ranking Market Barriers. Clearly, there are major barriers to greater use of
commercial HPWHs, even in applications where they offer substantial life-cycle advantages. The
barriers described above are common to emerging technologies. Industry participants argue that
potential customers are simply unaware of the technology, although it has been available for over
a decade. The few who know (or are made aware) discount the direct (lower costs for water
heating) and indirect benefits (local air conditioning). In part, these problems reflect the lack of
credible third-party information (such as case studies and rating methods). Because the benefits
are real, we infer that the industry has not been able to consistently establish a customer value
proposition that works.
17
ESTABLISHING INFORMATION RESOURCES FOR CUSTOMERS
The objective of this task is to increase the supply of credible, independent information about commercial
HPWHs available to all market actors. As noted in the “Background” section of this report, one of the
differences between emerging and mature products in the marketplace is the latter’s projection of a mature
infrastructure. Mainstream products are fully supported by an infrastructure that lowers the cost of choosing
the product and decreases the risks associated with specifying it (Moore 1999).15 Information is a key
component of this infrastructure. Some information items are costly in the framework of an emerging
business with very limited cash flow. In addition, a single firm that invests in activities that raise general
awareness or meet general industry needs will incur costs not borne by its competitors, disadvantaging it in
the marketplace.16 Public interest market transformation projects can fund other some information
resources, and do so as credible third parties perceived as objective and independent.
This project particularly addressed the following important components:
1. Web presence, as a hub for information for the industry at large.
2. Industry performance standards, to allow customers, contractors, and other designers to
compare performance across models. This is discussed in the “Establishing Industry
Standards” section, below.
3. Impartial sizing methods and other software tools that help contractors and design engineers
choose the right combination of parameters (such as HPWH capacity and hot water storage
capacity to best balance first costs, operating costs, and user needs for both hot water and
cooling). This is covered in the “Developing Technical Tools” section, below.
4. Engineering case studies that give confidence that the technology can be installed and deliver
value to customers. This is discussed under the “Field Study” section, below.
Addressing the first issue, web presence, part of the web site has been developed as a locus for information
on commercial heat pump information. The ACEEE/NYSERDA HPWH site is
http://aceee.org/buildings/coml_equp/hpwh/index.htm. This information includes the products of this
research project. It also includes links to NYSERDA, sites of manufacturers, other industry participants,
and other public interest projects. From time to time, research reports and other public domain information
will be added or linked. Of particular interest may be the performance-rating method and sizing method
developed in this project.
15 See particularly the discussion of “whole product planning, starting p. 112. 16 Anecdotally, the manufacturer who had been most active in raising awareness of the technology was
a key proponent for forming the Geothermal Heat Pump Consortium (GHPC) to spread these costs among manufacturers and interested parties such as utilities and the Department of Energy.
18
ACEEE is also undertaking a major revision and update of prior work on emerging technologies (Nadel
et al. 1998). A major difference between the new work and prior efforts is that the primary work product of
the new effort will be published dynamically on the World Wide Web at the ACEEE site. Ongoing work on
this project is likely to extend the HPWH component of the ACEEE site.
Results: Information Resources
The results of the information resources phase of this project are an increase in key kinds of information
available to market participants. In part, this material will be latent and will not have its full impact until
market forces, regulation, or other influences increase interest in commercial heat HPWHs.
ESTABLISHING INDUSTRY STANDARDS
The objective of this project phase was to help establish industry standards to facilitate comparing products
from different manufacturers. The ability to do “comparison shopping” gives potential customers
confidence that the technology is real and subject to some market discipline. In addition, just as a shopper
finds it hard to compare prices of milk sold in quarts with milk sold by the liter, until there are
standardized, industry-wide test conditions and rating methods, it is not possible to evaluate the potential of
competing products.17 In the case of commercial-scale HPWHs (sizes greater than 6 kW), a method of
testing was developed, but has not been converted into a standard in a form that could be adopted by a
technical organization. The method of testing is ASHRAE 118.1–2001 (ASHRAE 2001). During this
project, subcontractor Caneta Research developed the language required for 118.1 to be made a (consensus
or regulatory) standard for commercial HPWHs. This document (Appendix 6) is now available for use by
any industry group that would adopt a standard to allow competition on a “level playing field.”
Two different trade associations would be logical hosts for a commercial heat pump water heating standard
in the United States. GAMA (Gas Appliance Manufacturers Association) tests and certifies boilers and
water heaters. On the other hand, ARI (Air-conditioning and Refrigeration Institute) generally rates “hard-
wired” (installed) vapor compression (refrigeration) devices such as central air conditioners and heat
pumps.18 Both organizations have been made aware of this project’s work through letters to their technical
17 Performance standards and rating methods of this type are generally developed as industry
consensus documents by trade associations for their manufacturer members. One example would be the ground-source heat pump standards maintained by the Air-conditioning and Refrigeration Institute (ARI). In many cases, these standards are adopted into mandatory performance regulations, such as the minimum legal performance allowed for central air conditioners and furnaces under U.S. law.
18 A third organization, AHAM (Association of Home Appliance Manufacturers) rates refrigerators, room air conditioners, and similar “plug-in” refrigeration devices.
19
staff directors.19 When there are again enough manufacturers with enough interest, the standard developed
by Caneta will be available for adoption, with ASHRAE 118.1–2001 as its method of testing.
In conjunction with this task and its work on a sizing method, Caneta Research also compiled a report on
performance data for the industry today. That report, attached here as Appendix 7, is discouraging because
it suggests a decline of the commercial-scale HPWH market since this project began. This appendix and
subsequent manufacturer inquiries have been used to populate the model’s database for the sizing tool (as
discussed in “Developing Technical Tools”). Unfortunately, it appears that most of the half dozen or so
manufacturers20 who were active when the project began have left the commercial HPWH market and that
Colmac and E-Tech are the only manufacturers still serving the market.21
The result of the industry standards work has been to make additional foundation stones available for the
industry. At such time as there is market demand, whether induced by energy prices or other factors,
standards are available and ready for adoption through customary consensus processes—it is much easier to
begin the process with a draft document than with a blank sheet.
FIELD STUDY One objective of the project was to build confidence in the technology by documenting performance in the
field. To accomplish this, ACEEE and its subcontractor (CDH Energy) located a suitable site and
monitored system performance from March through May, 2002. The field study (see Appendix 8) included
performance documentation of the HPWH and determined any improvements in the system that might be
recommended. The selected site, the Geneva Lakefront Hotel, had been the subject of earlier monitoring
studies by CDH Energy (of its ground-source heat pump space conditioning system) and thus was
accustomed to working with field engineers. Almost as important, the site was close to the office of the
CDH Energy, who had equipment still in place.22
For this project, CDH Energy studied the kitchen of the hotel restaurant as a case study example for “full-
service” or “sit-down” restaurants in New York State. In addition to diners and events in the community,
19 Letters from H. Sachs, ACEEE, to F. Stanonik (GAMA) and M. Menzer (ARI). Sachs also met with
both to discuss the opportunity. When there is sufficient interest, each is expected to poll his manufacturer members to determine which organization they prefer to handle the certification program.
20 Including Addison Products, Dectron, and Nordyne. At least the latter two were regarded as important vendors.
21 HPWHs seem to have been a product on the verge of widespread adoption for at least a decade. One can only speculate why individual firms exited, but one principal reason would seem to be that prices (and expected future prices) of alternative fuels have not risen enough to increase the attractiveness of investments that would reduce these costs.
22 The subcontractor, CDH Energy, Cazenovia, N.Y., contributed use of sophisticated monitoring equipment that was already in place as a cost-sharing component.
20
the restaurant provides guests of the 100,000 square foot hotel (149 guest rooms) with a full-service
restaurant open from early morning until 10:00 pm. The CDH instrumentation monitored total hot water
use and also the use by each of six sinks and the dishwasher in the 1500 square foot kitchen. CDH also
monitored outdoor air temperature, and the kitchen air temperature and relative humidity at two locations in
order to infer the value of air conditioning that could be provided by HPWHs. An initial finding is that the
internal loads of the kitchen (stoves, heat rejected by refrigerators and freezers, etc.) are large enough that
space heating the kitchen was required only 168 hours in the winter of 2001–2002.23 This suggests that the
cooling action of HPWHs that extract heat from the kitchen will rarely lead to additional heat being
required.
The facility studied uses four 10-ton water-to-water HPWHs that extract heat from the ground-source heat
pump loop that provides space conditioning (heat and air conditioning) for the entire hotel. Because the
hotel rejects so much heat to the ground (relative to heat extracted), using the loop for water heating lowers
loop temperatures, improving the performance of the space conditioning system in the cooling season.
CDH determined that it is highly likely that one of the HPWHs is not performing optimally. This leads to a
lower COP (coefficient of performance) for the system than would have been inferred from the
manufacturer’s literature (and is one reason why a performance standard will be helpful for the industry).
Using water-to-water HPWHs integrated with the ground-source heat pump system was smart design for
this building. But this design does not give the kitchen any (air-source) HPWHs that would provide spot
cooling with dehumidified air for individual work areas. This complicates determining what the
performance of more common air-source HPWHs would be since there is no direct measure of the value of
the air conditioning benefits to the kitchen. However, by carefully monitoring outdoor temperature, indoor
temperature and humidity, and hot water energy use, CDH was able to build a simulation (model) of the
kitchen water heating and space conditioning needs. CDH used this model to examine the performance and
economics of an air-source system that could be installed either upstate (Rochester) or downstate (NYC) to
meet the loads characteristic of this commercial kitchen.
Results of the Field Study
The most important result of the monitoring study is the demonstration that water heating needs, on
average, are rather even through the hours when the restaurant is open. The upper line of Figure 1 shows
the hot water use by the hotel, including the kitchen. The use is highly variable through the day, peaking
when guests shower in the morning (and later when the laundry operates, from 9:00 am till 2:00 pm). In
contrast, the lower line shows the steady hourly profile for hot water used by the kitchen. For the three
23 Commercial structures generally have relatively high cooling loads compared to their heating loads,
but 168 hours is only about 6% of the roughly 2700 heating load hours of a house in the same region.
21
months of data acquisition, it appears that hot water is being used whenever the kitchen is open, and little
hot water is used when it is closed. This means that the spot cooling benefits of an air-source HPWH would
be available when they are needed, with relatively little hot water storage required to “buffer” the relatively
small fluctuations of hot water use and kitchen occupancy. This implies that full-service restaurants are
likely to be a very attractive application for HPWHs. This is particularly true for hotel kitchens that
typically serve breakfast, lunch, and supper, and thus have the long staff occupancy to benefit from cool air
and dehumidification.
Figure 1. Hot Water Use Profile for Kitchen and Entire Building. Source: Henderson et al. 2002
Building and Kitchen Average Flow Profile
22: 0: 2: 4: 6: 8: 10: 12: 14: 16: 18: 20: 22: 0:0
2
4
6
8
10
12
Flow
(gpm
)
Building Average (6,208 gpd) Kitchen Average (1,982 gpd)
In addition, the restaurant kitchen requires heat very few hours of the year. This means that there are few
hours when an air-source HPWH would cause the space to become too chilly, thus requiring heat. For the
bulk of the operating hours, an air-source heat pump system would make working conditions better by
dehumidifying and cooling the air at uncomfortable work stations, such as stoves and dish washing areas.
Finally, there was one surprising finding, not forecast by any of the interviewees. Sometimes, HPWHs do
not work as well as promised, which compromises their reputation. The measured performance at the
Geneva Lakefront Hotel suggests that one of the four heat pumps is likely to be performing poorly, in a
way that is not obvious without careful technical work. For this reason or others, the cost of water heating
with this system is higher than with a natural gas system. (Because it extracts heat from a ground loop used
to air condition the hotel, this system does have ancillary benefits, not accounted for, in improving the
22
efficiency of the overall system at the hotel.) This surprise notwithstanding, this study has demonstrated the
relatively high potential of HPWHs to serve full-service restaurants.
DEVELOPING TECHNICAL TOOLS
The objective of this phase of the project was to design and develop a tool to help contractors and other
middle-market participants easily select the right HPWH and ancillary equipment to meet the needs of
particular applications. This “tool” is a spreadsheet24 available on the ACEEE/NYSERDA web site. The
user begins with a screen labeled “HPWH Input” by choosing a model from the database or populating the
database with information for a new unit. She then enters values for the water heating load, and for the
costs of the HPWH system and an alternative to be compared. At the command “calculate,” the tool
presents “Economic Output” values including simple payback and return on investment. It also calculates
system performance parameters (HPWH COP, System COP, and HPWH Daily Operating Hours).
This tool responds to two different market barriers identified during the interview phase of the study. First,
choosing a water heating technology does not rank high relative to all the other decisions that a designer (or
business owner) has to make. If the process takes more time than the decision-maker perceives it to be
worth, she will simply infer that the risks are too high and the benefits too low, and choose a conventional
technology instead. Because HPWHs have high initial costs relative to other water heating methods,
oversizing is expensive, but undersizing leads to very high bills (if resistance heaters are used for back-up)
or dissatisfaction if tasks cannot be discharged for lack of hot water. An easy-to-use sizing tool will reduce
the time and cost of choosing a good water heating option. Second, manufacturer-specific sizing methods,
like other aspects of the sales process, are likely to be perceived as biased. By having an independent third
party with no connection to the vendors provide the sizing method, this barrier can be neutralized.
Success in this task required a sound underlying algorithm for sizing. Thus, this task was built on the
ASHRAE 118.1 method of testing, which was developed by a consensus process including manufacturers
and other experts. It also requires good input data from tests done by the selected standard rating method.
Because such data are not yet available, the present sizing tool currently uses manufacturer’s uncertified
performance data. When there is manufacturer interest, the performance standard developed in this project
will be available as a basis for a certification program.
24 Developed by Caneta Research, Inc, under a subcontract with ACEEE.
23
24
Section 3
IMPACTS FOR NEW YORK STATE
This section focuses on the potential benefits to New York State of this commercial HPWH project. The
objective is to examine energy or peak demand reductions, and market transformation impacts.
Because no installations of commercial-scale HPWHs in New York State are known to have occurred
because of the efforts of this program, no savings of energy can be claimed at this time. As shown by the
field study and the simulation work as part of that project phase, commercial HPWH installations can save
substantial energy while improving working conditions. If properly sized and installed in an appropriate
application, the COP of the units suggests that such an installation would use about 40% as much electricity
as resistance water heating. Compared to gas water heating, it would use perhaps 60% as much site energy,
but much more source (power plant) energy. However, because of the price of gas per Btu of delivered site
energy is much less than that of electricity, HPWHs may not appear to save money for the owner if the
evaluation excludes air conditioning benefits.
Peak demand is also a key parameter for planning the power system. However, estimating the impact on
system demand of large numbers of commercial HPWHs is more complex than estimating energy savings.
Figure 2 illustrates the data requirements and analysis pathways required to provide a definitive response.
Appendix 5 develops the topic more completely. For a given installation, the likely result ranges from
adding to peak requirements (alternative fuel is fossil, space is not air conditioned and the HPWH is in use
during system demand peaks) to a significant peak reduction (factor of 2.5, if the space is air conditioned,
uses resistance water heating, and does not have a mechanism to limit peak power draw). Of course, system
demand will be less than the unit demand, unless all the heat pumps in all installations are running at the
same instant. The reduction factor is called load diversity.
25
Figure 2. Analysis Framework for Evaluating HPWH Impact on System Peak Demand. Per Installation Impact Depends on Whether the Space Served Is Air Conditioned, the
Alternative Source of Water Heating Energy, and the Pattern of Water Use (Relative to Storage). SHW means Service Hot Water.
Is the space air-conditioned?
NoHPWH will probably add to peak
Yes
Is SHW produced by fossil fuel?
Yes
NoThen SHW is elec. resistance
Is SHW on a time clock (no peak draw)?
Modest effect, depends on efficiency of A/C & HPWH
No
Roughly 2.5-fold peak reduction
Yes
Add a bit to peak unlessstorage is large relative to use
MARKET TRANSFORMATION IMPACTS IN NEW YORK STATE
During the time between contract award and the project’s end, there were signs of increasing challenges to
the commercial HPWH industry. Although two firms entered the residential market in the last two years,25
several firms have exited the commercial HPWH market. There is now a small but significant commercial
market in Hawaii, where high utility and fuel prices, combined with very temperate year-around outdoor
temperatures (with no freezing danger), has led to roof-top installations that extract heat from ambient air.
We are unable to find substantial evidence of real business activity elsewhere.26 The withdrawal of
manufacturers has seriously slowed market transformation. The HPWH web site developed under project
auspices, the case study from field monitoring, and the sizing spreadsheet are all in place to support future
market transformation efforts by NYSERDA or others. ACEEE will maintain the web site (which indicates
25 One of these, ECR International, is a New York State firm manufacturing a product developed and
brought to market with federal and NYSERDA assistance. 26 We informally surveyed participants in a recent DOE workshop in Atlanta, Georgia.
26
NYSERDA sponsorship) and augment it as project work leads to additions, or as significant work products
by others are made available for linking.
On the other hand, the identification of priority market segments and significant barriers in this project will
help the market grow when new opportunities arise. As outlined in the “Discussion” section below, the
near-term outlook could be changed by a major program by NYSERDA or others. This could
simultaneously address lack of awareness and high purchase prices, and could draw new middle-market
practitioners and suppliers into the market. In the residential sector, such a program would traditionally be
structured around rebates or other direct incentives to purchasers. The commercial sector is characterized
by smaller numbers of sales of much larger capacity, and by more-or-less “engineered” (customized)
installations. Under these circumstances, design assistance, training, or even incentives to middle-market
participants could be more effective. As one example, a public entity could underwrite the cost of having
certain common HPWH capacities available from in-state distributors, eliminating perceived risks of
delivery delays.
27
28
Section 4
DISCUSSION
This section recapitulates the major findings of the project and evaluates its major successes and shortfalls.
The last component of this section is a set of recommendations for NYSERDA consideration.
MAJOR FINDINGS
The major findings of this report include the following:
• Identification of the market segments that industry experts rate as having the greatest potential
for early exploitation of commercial HPWHs. These segments include full-service restaurants
(dishwashing, food preparation, wash-down, and lavatories), health care and assisted living
facilities (kitchen and laundry uses), and coin-operated laundries. Lower priority targets
would include larger scale commercial laundries and linen services, and hotel and motel
applications (laundries, kitchens, pools, and guest services). This work was done in a way that
allows public interest agencies such as NYSERDA to change input parameters to study how
respective “weightings” of the variables would change the segments selected, allowing a form
of sensitivity analysis to be applied to program design.
• Documentation of the major barriers to installing more commercial HPWHs in New York
State. The two most important are inadequate awareness of the technology among potential
middle-market participants and their customers, and the perceived high first cost premium for
HPWHs relative to conventional water heaters (or boilers).
• Documentation of system performance by monitoring a relatively large restaurant kitchen in a
hotel and extending the results by simulation of upstate and downstate installations. This has
shown, for the first time, that full-service restaurants may be a very attractive early target for
HPWHs.
• Production of a performance standard for use with the ASHRAE 103 rating method. When
manufacturers and the market are ready for a certification program, this is available for rapid
adoption by one of the potential trade associations.
• Development of a sizing tool (spreadsheet) populated with manufacturer capacity data. As a
third-party, independent, and free tool available to all designers, contractors, and owners, this
will ease the burdens of determining the appropriate HPWH size and storage capacity
required for a particular application. As a third-party product, it is more likely to be seen by
stakeholders (particularly customers) as unbiased.
29
• Construction of a web site that will continue to offer the HPWH community and all potential
market participants improved understanding of the field. The web site includes the practical
sizing method, and performance standard, this report, and links to other relevant sites.
PROJECT SUCCESS AND FAILURES
ACEEE believes that the most important obstacle to increasing sales of commercial HPWHS in New York
State is a market that is so immature that market transformation programs cannot yet get traction. When
there is very low awareness of the product, essentially no market participants interested in seeing more
units installed, and virtually no customers who could find products even if they want them, the market may
not yet be ready for transformation.27 One perspective on this problem, an analogy, is that trade
associations often do not publish sales data for product categories where fewer than three manufacturers
have significant market presence. To do otherwise would tell each firm what the other is doing. Until there
are multiple vendors whose success requires major efforts on behalf of the industry, market transformation
programs may be premature for capital equipment. In the present case, the collapse of the commercial
HPWH market to two active vendors means that the remaining firms must focus their efforts where sales
seem most likely. Today, that is Hawaii (and some export markets).
As the precarious position of the industry became clearer, it seemed preferable to reduce resources and
focus on activities that would have long-term benefit to New York State. This meant deferring “close
support” such as trade show activities in favor of activities that would have longer-term benefits. Thus, the
Project Manager and Principal Investigator agreed to focus on a field study, and information and tools that
would be relevant for designers, contractors, and their clients when the market is ready. These tasks have
been completed successfully.
RECOMMENDATIONS
Based on the results of this project, ACEEE recommends that NYSERDA consider ways to encourage
greater use of this promising technology. Because of the severe limitations of the market today, success
will require both time and investment, but the great energy savings potential for customers may make it
worthwhile. ACEEE proposes the following course of action (in approximate priority order from most to
less important):
• Select and focus on one market segment. The goal is to develop allies among the users and
vendors who serve a particular segment so that the word can be spread credibly by its market
30
participants. We recommend full-service restaurants for two reasons: they were most highly
ranked by our interviewees and we now have good data and a case study supporting the value
of HPHWs for this segment.
• Put 5–10 HPHWs into full-service restaurants and monitor the results. Restaurants where natural
gas is not available should be selected, if feasible. Suitable locations can be found by
announcements through the restaurant industry of New York State. It may be advisable to seek
sites by making the installation free to selected participants, in return for the right to monitor
energy and water use. Participants should be required to share appropriate data (such as meals
served) with NYSERDA as a condition. Build both engineering studies and marketing materials
from the performance documentation of the exemplary installations. Be sure they are exemplary
by contracting with one or two firms to design and install all of the systems so that the installer(s)
can be held accountable and will have incentives to make it work right.
• Consider collaborating with an in-state manufacturer. ECR International has developed a smaller
HPWH, primarily designed for residential applications, that may be suitable for smaller
restaurants—or ECR may be interested in providing prototypes of a larger commercial design.
This would be a logical step in NYSERDA support for the evolution of the industry and would be
a bridge between NYSERDA research and market transformation activities.
• Exploit the case studies from the monitored sites. The proposed case studies would all be within
the same industry, full-service restaurants (or other segment selected by NYSERDA). With the
information on the web site, manufacturers’ materials, and other literature, a “circuit rider” could
carry the story to the industry’s meetings (as talks and exhibits), and franchisers and owners of
multiple restaurants, etc.
• Consider using financial incentives to buy down the incremental cost of design and purchase for
the first hundred or so installations in order to give all parties reasons to want to try the
technology. Many market transformation programs, including some by NYSERDA, have offered
financial incentives to compensate early adopters for perceived incremental risks. In return, the
sponsor of the incentives can insist on the right to monitor hot water and electricity use. These
financial incentives could take many forms. In the residential sector, such programs have generally
been structured around direct financial incentives to purchasers, as rebates or tax credits. The
commercial sector is characterized by smaller numbers of sales of much larger unit capacity and
by more-or-less “engineered” (customized) installations. Although incentives to purchasers will
raise awareness, other approaches cold be effective at lower cost. These might include design
assistance, training, or even incentives to middle-market participants. As one small example, a
public entity might underwrite the cost of having certain common HPWH capacities available
from in-state distributors, eliminating perceived risks of delivery delays.
27 This observation seems to be generally applicable to high capital cost products. It may not be true for
31
• Back out. After two years or so of full buy-downs, ramp down the incentives for purchase, to
expose the market to some discipline.
CONCLUSIONS
Commercial-scale HPWHs are a very promising technology. However, their present market share is
extremely low, and only two or three manufacturers are seriously involved in the market.28 The market
needs further conditioning for successful market transformation. The next step in this market conditioning
is likely to be further demonstrations and developing additional, well-documented case studies that will
support sales efforts to designers and customers.
The current project has successfully identified high-potential market segments for early adoption of
HPWHs, documented barriers, and developed support tools and information. All of these will be useful in
supporting increased utilization of the technology. However, as a practical matter, this project has not
succeeded in market transformation. It has not (yet) increased the sales or installation rates for commercial
HPWHs in New York State. In retrospect, after the project was launched the number of HPWH
manufacturers declined substantially. There seems to be virtually no sales infrastructure for commercial-
scale HPWHs left in New York State today.29
On the other hand, the identification of priority market segments and significant barriers in this project will
help the market grow when new opportunities arise. As outlined in the “Discussion” section above, the
near-term outlook could be changed by a major program by NYSERDA or others. This could
simultaneously address lack of awareness and high purchase prices, and would draw new middle-market
practitioners and suppliers into the market. ACEEE remains optimistic that the future will see much-
expanded market penetration of this promising technology.
low-cost products, which have low risks to the purchaser.
28 None of these manufacturers is based in New York State. 29 ECR International, Utica, NY, is launching a line of small (residential) HPWHs whose development
has been fostered by NYSERDA. These products are smaller than those considered in this report.
32
REFERENCES
ASHRAE, 2001. Method of Testing for Rating Commercial Gas, Electric, and Oil Water Heaters. American Society of Heating, Refrigeration, and Air-conditioning Engineers. Atlanta, Ga. American Society of Heating, Refrigeration, and Air-conditioning Engineers. [DOE] U.S. Department of Energy. 2002. Buildings Energy Databook: 1.3 Commercial Sector Energy Consumption. Table B-25. http://buildingsdatabook.eren.doe.gov/frame.asp?p=/chapterdisplaymain.asp?ChapterID=1. Washington, D.C.: U. S. Department of Energy. [FEMP] Federal Energy Management Program. 2002. Federal Technology Alerts: Commercial Heat Pump Water Heaters, Manufacturers. http://www.eren.doe.gov/femp/prodtech/10_comm.html#manu. Washington, D.C.: Federal Energy Management Program. Henderson, H., D.E. Ciolkosz, PhD., Walburger, A.C., 2002. Heat Pump Water Heater Performance in a Restaurant: Monitoring and Simulation Results from the Geneva Lakefront Hotel, Geneva, NY. Available at http://www.aceee.org/buildings/coml_equp/hpwh/index6.htm. Washington, D.C.: American Council for an Energy-Efficient Economy. Moore, Geoffrey A. 1999. Crossing the Chasm: Marketing and Selling High-Tech Products to Mainstream Customers. Revised Edition. New York, N.Y.: Harper-Collins. Nadel, S, L. Rainer, M. Shepard, M. Suozzo, and J. Thorne. 1998. Emerging Energy-Saving Technologies and Practices for the Buildings Sector. ACEEE A985. Washington, D.C.: American Council for an Energy-Efficient Technology.
Sachs, H. 2002. Market Opportunities for Commercial-Scale Heat Pump Water Heaters in New York State: Task 1 Report, NYSERDA Project 6299. Washington, D.C.: American Council for an Energy-Efficient Economy. Sachs, H. and S. Smith. Forthcoming. Market Transformation for Distribution Transformers: Final Report for NYSERDA Project 6298. Washington, D.C.: American Council for an Energy-Efficient Technology.
33
34
APPENDIX 1: AN ANNOTATED BIBLIOGRAPHY
ON COMMERCIAL-SCALE HEAT PUMP WATER HEATERS
ASHRAE, 1994. Technical Service Bulletin: New Information on Service Water Heating. V. 10, #2.
ASHRAE, 1791 Tullie Circle, Atlanta, GA 30329
Five essays. Two deal with measured use patterns in commercial buildings and multifamily
buildings, respectively. Another addresses a computer simulation developed for EPRI.
ASHRAE, undated, Commercial Heat Pump Water Heaters – Technology and Application. ASHRAE Short
Course Notes, A. Shedd, Presenter.
Excellent introduction to the topic, including sizing.
R.L.D. Cane and S.B. Clemes, 1996. Heat Pump Water Heaters for Residential and Commercial Buildings.
IEA Heat Pump Centre, Sittard, The Netherlands
General overview; excellent schematics; includes incentive programs
Caneta Research, Inc. Guidelines for the Evaluation of Resource and Environmental Benefits of Heat
Recovery Heat Pumps. Final Report, RP-807, ASHRAE, 1791 Tullie Circle, Atlanta, GA 30329.
Primary focus is industrial processes such as drying processes and mechanical vapor
recompression. However, the report includes a hospital kitchen application, a large water heating
and air -conditioning application in a resort complex, and a chicken processing plant.
Dupey, T., and M. Michel, (undated). Heat Pump Water Heater Market Potential Assessment: Consumer
End User. Prepared for Alabama Power Co. Decision Analyst, Inc, Arlington TX, 76011.
Rare survey of customer values and motivations.
EPRI, Commercial Heat Pump Water Heaters Applications Handbook, 1990. Prepared by A.C. Shedd and
D. W. Abrams. Electric Power Research Institute Report CU-6666s.
A thoroughly professional and well-written report on HPWH potential and applications.
Unfortunately, availability to others than EPRI members who support that business line has been
very spotty. Interested readers may want to begin with ASHRAE Short Course notes by A. Shedd,
one of the authors of the EPRI report.
FEMP (Federal Energy Management Program, US DOE), 1997. Commercial Heat Pump Water Heaters.
Federal Technology Alert. 28 pp. Available from
http://www.eren.doe.gov/femp/prodtech/pdfs/FTA_HPWH.pdf
35
The best and most concise resource available. Overview of the technology, sizing, manufacturers,
a case study, and other guidance.
FEMP (Federal Energy Management Program, US DOE), 1995. Residential Heat Pump Water Heaters.
Federal Technology Alert, 32 pp. Available from
http://www.eren.doe.gov/femp/prodtech/water_heat.html
Excellent review. Includes breakeven electricity costs for replacing resistive water heating, annual
entering cold water temperatures by city, manufacturers, design guidance, etc.
Hiller, Carl. Water Heating Technology Review and Competitive Technology Issues. Short Course Notes.
For information, contact author, [email protected], (530)758-3035.
These notes are largely a compilation of articles from EPRI “Electric Water Heating News.”
Hiller is assumed to have been the principal author.
Shedd, Alan. Commercial Heat Pump Water Heaters – Technology and Applications. ASHRAE Short
Course, January, 2001. May be available from ASHRAE, 1791 Tullie Circle, Atlanta, GA 30329.
Excellent overview, with sections on loads and calculations; fundamentals, design, and
applications; installation design and maintenance; problems; and checklists. May be assumed to
cover the major points in the EPRI handbook, for which Shedd was the principal author.
Tennessee Valley Authority, (undated). Heat Pump Water Heater Reference Manual. (made available by
TVA staff). Four sections: “General” introduction; a Lotus-based computer simulation program;
equipment notes, and Applications and Examples.
TVA’s program was relatively dormant for several years, so some of this material is not current.
Includes:
• Sizing method logical development paper, for spot cooling/water heating applications
• Brief description of triple function heat pump with exterior supplemental evaporator.
• Extensive case study material on Super Wash House coin-operated laundry, Knoxville,
TN.
• Short blurbs on installations at full-service restaurant (600 meals/day, chain); solar/hp
hybrid nursing home (35 gal/patient-day) and motel; lots of other examples outlined.
• Equipment lists. Many of the devices described are not currently available.
Weingarten, L, and Weingarten, S., 1998. The History of Domestic Water Heating. PM Engineer, October,
p. 72 – 77.
A nice essay giving some historical context.
36
Some miscellaneous web sites, exclusive of those housing documents cited above:
http://www.greentie.org/class/ixf12.htm
very generalized four-paragraph introduction, not very helpful
http://hes.lbl.gov/hes/makingithappen/no_regrets/waterheaterheatpump.html
Nice 1-page description and suggestions, with a graphic.
http://www.fpc.com/learning/tips/pumps.html
Rather tepid endorsement for residential units.
http://www.energydepot.com/wpsc/library/htpumpwh.asp
Another utility site, pretty objective
http://www.pnl.gov/techguide/21.htm
Good introduction, with links to other sites.
http://www.ladwp.com/energyadvisor/EA-26.html
Excellent treatment, from E-Source.
http://www.ftc.gov/bcp/conline/edcams/appliances/tables/waterheater.htm
Federal Trade Commission site, showing how few models were on the market.
Manufacturer Web Sites for commercial-scale equipment:
http://www.aeretech.com/
http://www.colmaccoil.com/coil/hpwh.htm
37
38
APPENDIX 2: SURVEY INSTRUMENT
MARKET SEGMENTATION TERMS USED
Application: A task or service carried out by a commercial heat pump water heater. Examples include
heating water for dishwashing while cooling the dish washing work area, and heating water for showers
while cooling and dehumidifying locker room. That is, the term refers to an end use, regardless of the type
of organization employing it.
Industry: A major group of customers engaged in the same business. Examples include schools, hotels and
motels, and restaurants. Designations are specific to this study. In particular, some classifications would
combine hotels and motels with restaurants in a hospitality industry. Since they tend to have separate trade
associations (that is, see themselves as distinct), we find it helpful to consider them as different industries.
(Market) Segment. A more-or-less homogeneous subdivision of an industry. The restaurant industry is
readily divided into fast-food v. full-service establishments, and the division is useful for our study. In
general, the former use disposable plates, cups, and utensils, while the latter have substantial dishwashing
operations. In general, the former rely much more on pre-packaged food portions, while the latter do more
food preparation on site. This means more hot water use for clean-up.
39
ACEEE/NYSERDA COMMERCIAL HEAT PUMP WATER HEATER PROJECT INTERVIEW RECORD
Background Information:
Date: _______________________Time:___________________ Interviewer Initials:________
Interviewee:
Name:________________________________________Title:________________________
Firm:
Contact Information:
Address 1
Address 2
City State Zip Code
Phone: Fax
Segment represented (circle one):
Government Agency (named) Code officials
Manufacturers Distributors, Sales engineers
Ratings groups (GAMA, ARI) Other Trade Associations
Designers Installers
Owners and potential owners Utility staff (TVA, CLP, NY utilities…)
A bit on the project (background script)
• Hi, I’m Harvey Sachs, of ACEEE.
• As we discussed before I sent out the list of questions, we are conducting a commercial heat pump
water heater survey of key market participants in NY State on behalf, of NYSERDA, the New York
State Energy Research and Development Authority. I’m helping NYSERDA understand the market for
commercial heat pump water heat market. We have several goals:
• Understanding what commercial and institutional customer groups might gain most from these
units, which efficiently provide both water heating and spot air conditioning. We really want to
understand which segments you think are good (or bad) bets, and why.
• Gaining insights into the major market barriers you foresee.
40
• What are the levers that move the market players in the segments you consider the best bets? Who
are the decision-makers and influencers?
• Get your recommendations on others with experience in this area, and the trade groups that
represent them and can help us understand the size of the potential markets.
What is your estimate of the present size of the total US market for HPWH for commercial applications?
What, if anything, would improve the prospects for HPWH in commercial and institutional sectors?
The market segments
Attachment 1 (of this survey) is a list of segments we’re thinking about. We’d like your help with assigning
priorities for our efforts. Please feel free to assign each of the priority levels to as many segments as it
applies to, using the guidelines on the sheet with the table.
What important segments have we left out but should consider?
The market barriers
Attachment 2 (of this survey) is a list of market barriers that may discourage potential customers from
considering HPWH. As for Attachment 1, we’d like your help in ranking these, so we can allocate our
effort to make the most difference.
One of our tasks is to monitor the performance of some commercial heat pump water heater installations in
New York State. Do you know of any such installations, or know someone who is likely to be able to help
us find good sites? Info?
Another task is to make an applications selection tool available to the industry. We want to use a simple
and transparent spreadsheet approach. One manufacturer has offered the use of its software, which the
project will test for accuracy and bias. Do you know of any tools that you would prefer that contractors,
designers, and customers have?
As this project develops, do you want us to keep in touch with you? If so, what is the best way?
41
• Email updates, perhaps monthly?
• Let you use the web site with information resources?
• Fax updates?
What other advice would you offer the project team?
Other comments:
42
Survey Attachment 1: Potential Market Segments
Segments and Priorities
End Use type: Laundry Kitchen
HW
General Service
HW
Lavatory, heat
recovery water
heating
Customer type:
Hotel/Motel
Restaurants, Sit-Down, Real Dishes
Restaurants, Fast-Food
Prisons
Health Care, Assisted Living
Linen/Uniform Services
Schools, K-12
Colleges, Dorm Applications
Military Housing
Retail Laundro-Mats
School Locker Rooms, Health Clubs
Swimming Pools, Indoor
Other Good Targets:
Please note if Priorities differ for new construction v. retrofit/replacement:
3 Good as early target, highest likelihood of success, might reach hundreds of units/year in NY; good
access to decision-makers
1, 2 Less attractive, but worth considering since (a) lots of installations, or (b) good decision-maker access
0 Hopeless: poor access to capital, short time horizon
43
Survey Attachment 2: Market Barriers That Might Be Important…
Ranking Market Barriers for Commercial HPWH
Priority Barrier described
Market uncertainty for mfgs and customers: look to plumbers or mechanical contractors?
Cost of Capital
Access to Capital
First cost premium too high for perceived value as water heater (long payback)
Early adopters very hard to find
Not enough awareness of the technology for sales reps to build on
Cost of “real estate” – space to put anything except dedicated water heater
History of poor support by some manufacturers (CH)
Good applications guidance to avoid oversizing (CH)
Lack of committed "evangelists" to sell the product
Lack of credible third-party information, such as (don't need to rank each in subset):
Lack of trade association to promote
Lack of good, well documented, case studies,
Lack of well-written and persuasive articles in trade magazines
Lack of certification/ratings program
Lack of "accepted" sizing software
Lack of "generic specifications" owners and designers can use as templates
Lack of "design details" for AutoCad, etc
Do building codes or inspectors make it unusually hard?
certification beyond safety?
double-wall heat exchangers?
installation drawings stamped by a licensed engineer?
Do State regulations have any impact? Which and how?
DISCUSSION OF THE INTERVIEW INSTRUMENT
The first part of the interview solicits necessary biographical information about the interviewee. Part 2 is a
pair of open-ended questions designed to help the interviewee think broadly about the industry:
What is your estimate of the present size of the total US market for HPWH for commercial
applications?
•
• What, if anything, would improve the prospects for HPWH in commercial and institutional sectors?
44
Part 3 lists market segments and applications, and asks interviewees to assign priorities to each. It also asks
participants to suggest additional segments. Participants suggested a few additional segments or
applications in this part of the interview, such as highway rest areas.
Part 4 asked participants to evaluate market barriers. In addition to those initially listed, early interviewees
suggested some modifications that were incorporated for subsequent interviews. These were:
•
•
•
•
•
Differentiating between “cost of capital” and “access to capital.” Historically, some industries have
had trouble borrowing funds at any interest rate, presumably because they lack collateral. An example
might include restaurants in leased space.
History of poor support or field problems with products from some manufacturers, which may have
tarnished the reputation of the technology.
Inappropriate applications guidance (sizing). This includes different kinds of problems, such as:
Simple guides that suggest sizing so the HPWH can carry the entire peak load of the facility. This
tends to specify equipment that is very large, idle much of the time, and so expensive that the
owner declines the HPWH option.
Guidelines that do not adequately consider the interplay among key factors, including the
coincidence of water heating and spot cooling needs, and the role of hot water storage in bridging
coincidence gaps.
Part 5 of the questionnaire sought specific information to help the project. The interviewer asked each
participant if he had knowledge of any commercial installations in New York State that might be suitable
for performance monitoring. No sites were discovered through the interviews. The interviewer also asked
each participant if he had any recommendation of a preferred application sizing tool that this project should
make available to New York decision-makers. Several interviewees suggested reasons not to use specific
programs, but no new packages were found that would be absolutely “right” for New York use. One
package, for example, has a $5000 user license fee, but restructuring in the parent organization suggests
that support may not be adequate, and that licensing for state-wide access would be very difficult. Another
package, which would be available to the project, is considered by one former user as too complex for field
applications.
The final interview questions asked how participants would like to track the progress of the project, via
email, fax, or other media. It evoked only weak preferences. We then asked two open-ended, closing
questions designed to elicit other suggestions for the project: “What other advice would you offer the
project team?” and “Other comments:”
45
46
APPENDIX 3: LIST OF INDUSTRY INTERVIEWEES
Firm Name Contact Name Position Phone
Number
USDOE James Brodrick Program Manager 202-586-1856
NY Dept. of
State (Codes)
Michael Burnetter Code Officer 518-474-4073 [email protected]
Alabama Power
Company
John Calhoun Applications
Specialist
Nyle Specialty
Products
Geoffrey Clarke Mktg. Mgr.
Tennessee
Valley Authority
David Dinse Research
Manager
Consultant, ex
EPRI
Carl Hiller Consultant
ECR
International
Karl Mayer Sales Man. 716-366-5500
ext. 274
Crispaire
Corporation
Titu Doctor Director 770-734-9696
Florida Heat
Pump Mfg.
Larry Eitelman Sales Man. 918-835-4086
DEC
International
Bernie Mittlestaedt 800-533-7533 [email protected]
NYSERDA Chris Reohr
Jackson EMC,
ASHRAE TC 6.6
Allan Shedd Commercial
Services
Roberts Services Bob Roberts distributor
WFI Tony Cooper Commercial Mgr. 800-934-
5160x3221
Carrier,
Incorporated
Wayne Reedy 315-432-6734
ORNL John Tomlinson Research man 865-574-0291
Johnson
Research LLC
Johnson Russ designer
47
48
APPENDIX 4: OPTIONS SPREADSHEET FOR ASSIGNING PRIORITIES
TO MARKET SEGMENTS, WITH DISCUSSION
Prioritizing Market Segments
Evaluations Load Characteristics
Market Segments
or End Uses
Auxiliary Uses Proposed
Rank Score
Ranked by
Inter-viewees
Flat- ness
HW and A/C
Coincidence
NY Installed
Base
log of NY
base
Notes
Parameter Weight 1 1 1 1 1 Maximum Possible Score
3 3 3 3 3
Full-Service Restaurants
Dishwashing 1 11.3 3 2 2 19,087 4.3
Full-Service Restaurants
Food Prep & Cleaning
Lavatory 1 10.3 3 1 2 19,087 4.3
HCAL* Laundry 2 11.5 3 2 3 3487 3.5 HCAL Food Prep
& Cleaning Lavatory 2 11.5 3 2 3 3487 3.5
HCAL Other Washdown 8.5 3 1 1 3487 3.5 Coin-Op Laundries
Laundry Lavatory 3 8.2 1 2 2 1636 3.2 Ranked as near-optimum by FEMP FTA on HPWH
Linen Services
Laundry 4 11.3 2 3 3 2182 3.3
Hotel/Motel Guest Service Water 7.5 2 1 1 3200 3.5 Hotel/Motel Laundry 5 8.2 2 3 1600 3.2 Hotel/Motel Restaurant 5.9 1 2 800 2.9 K-12 Schools
Food Prep & Cleaning
Lavatory 6 6.6 1 1 1 4000 3.6
Health Clubs, etc.
Locker rooms
Lavatory 7 8.2 1 2 2 1520 3.2
Health Clubs, etc.
Indoor Pools 7 8.2 0 3 3 152 2.2
Fast-Food Restaurants
Food Prep & Cleaning
Lavatory 8 9.2 3 1 1 17,218 4.2
Prisons Food Prep & Cleaning
Lavatory 9.9 2 2 3 730 2.9
49
Prisons Laundry 10.9 2 3 3 730 2.9
Prisons Other Washdown 6.9 2 1 1 730 2.9 K-12 Schools
Locker rooms 6.1 1 1 1 1169 3.1
K-12 Schools
Pool Heating 9.7 1 3 3 500 2.7
College Dorms
service hot water 8.1 0 2 3 1159 3.1
Highway Rest Areas
lavatory Washdown 8.0 0 3 3 100 2.0
Military Housing
service hot water - 1 2 2 0 N/A
Light Ind. Processing
service hot water - 0 3 3 unknown N/A
Scoring: 3: >1shift/day 46627 4.7 sum of possible install- ations
2: 1 shift
1:epi-sodic
0:<1/ shift
Explanatory notes.
HCAL = health care, assisted living
The most important columns are D (proposed rank) and E (score determined from evaluation of interviewee
responses). The most important rows in the analysis are 4 and 5, parameter weight and potential score.
Rows 6–28 name and describe a discrete market segment (sub-industry) and an application in it, such as the
dishwashing application in the full-service restaurant segment. Rows 4 and 5 are weighting factors for the
column parameters. Row 4 is the Parameter Weight. It establishes the relative value for the parameters in
columns F through I. Changing the weight (say, from 1 to 10 or 0.1) changes the relative of the parameter
in that column (for example, number of installations, in Column I). Row 5 is the Maximum possible score.
This is set this to 3 for each column, to simplify analysis. This allows the analyst to focus on weighting
factors (Row 4) in considering alternative weights for the columns.
The columns are divided into four groups:
Group 1,The first three columns, carries the segment/application name information.
50
Group 2, columns D through F, is a set of evaluations of the segments/applications, and is the “output” of
the tool.
Column D, “Proposed Rank,” is ACEEE’s priority judgment. It is based on the scoring in column E.
However, it also incorporates other factors. One example of this is the high priority (2) assigned to coin-
operated laundries by the Federal Technology Alert (FEMP1997). The score (Column E) for this market is
relatively low, reflecting the experiences of the interviewees.
Column E, “Score,” reflects the weighted judgment of the interviewees and all of the group 3 (Evaluation)
technical and market factors.
Column F, “Ranked by Interviewees” is the priority assigned by interviewees, based on the feasibility and
importance of early market transformation for the specific segment. The scale for this parameter was
limited to range of 1 – 3, with higher numbers having higher importance.
Group 3, “Load Characteristics,” represents technical characteristics and present market penetration.
“Flatness” (Column G) is an estimate of the load constancy over the 24 hr day. The more hours per day
that the application calls for water heating, the smaller the required storage for a given heat pump capacity.
Flatter loads can be met more economically. HW and A/C Coincidence (Column H). The best applications
need hot water and spot air conditioning at the same time. An example might be a restaurant kitchen
dishwashing station, where the air conditioning and dehumidification will be valued whenever dishwashing
needs hot water. Poor coincidence (and in this case, poor load flatness) would be represented by a kitchen
that only used hot water for hand-washing (small amounts) and daily wash-down (large amounts). It might
need 14-hour cooling in the cooking area, but use the vast majority of its water during a single hour.
Columns I and J are two representations of the estimated installation potential in New York State for that
application. Column I is the raw count or estimate. Because it spans such a large range (from a few hundred
to 20,000), we actually did our scoring with the logarithm of the Column I numbers, in Column J. Since log
100=2, and log 10,000=4, this has the effect of compressing the range so the largest numbers do not
overwhelm the scoring.
Clearly, the most important columns are D (proposed rank) and E (score determined from evaluation of
interviewee responses). These have been the major contributors to ACEEE’s ranking of segments.
However, the structure of the Options Spreadsheet allows NYSERDA or others to alter weighting factors
(or even introduce new parameters) to aid in further evaluation or decision-making.
For a particular application (Rows 6 through 28), the score assigned is the outcome of a formula that
includes modified values of the four decision parameters: Rank by the interviewees, judgment of load
flatness, judgment of coincidence of hot water and air conditioning demand, and an estimate of the number
of potential installations in New York. For each of the four parameters, the value is the product of the
(parameter value) times the (parameter weight), divided by the (maximum possible score) for that
51
parameter. The sum of these four weighted values is divided by 4, the number of parameters, gives a score
that is the sum of the parameter values for the application (such as dishwashing in full-service restaurants).
The values of the potential installation estimates numbers were transformed to reduce the variability to
about the same scale as the other parameters. In particular, the values used are those of Column J, the
logarithm of the potential number of installations in Column I. From a pragmatic perspective, this is
appropriate: for program selection and design purposes the twofold difference between 500 and 1000
potential installations may be as important as the difference between 19,000 and 20,000 installations.
The formula is specified in this indirect way to allow analysts to re-rank applications by carrying out
“what-if” exercises. For example, if she decides that load flatness should have twice the emphasis of the
other parameters, she just changes the entry in cell G4 from “1” to “2”. Thus, the analyst can most easily
trace the effects of re-weighting by changing the parameter weight in row 4; she may also change the
potential score to achieve the same result.
NYSERDA elected to utilize the default weighting factors selected by ACEEE, leading to the identification
of priorities as discussed in the Results section, below.
Further Details and Documentation
Rows:
Row 4: Parameter Weight. This establishes the relative weights for the parameters in columns F through I.
Changing the weight (say, from 1 to 10 or 0.1) changes the relative of the parameter in that column (for
example, number of installations, in Column I).
Row 5: Maximum possible score. We have set this to 3 for each column, to simplify analysis. This
allows the analyst to focus on weighting factors (Row 4) as a single variable.
Row 6-7: Full-Service Restaurants. From http://www.restaurant.org/research/state_stats.cfm. Full-
service ratio assumed to be the same as national ratio, 53%.30
Row 8–10: Health Care and Assisted Living. Two estimates were found. The US Census estimate, from
www.census.gov/epcd/ec97/NY000_81.HTM#N812, is 3487 sites, but Dr. Vera Prosper, NY
State OFA, finds 527 licensed facilities (email of September 28)
30 Personal communication from Robert Ebbins, National Restaurant Association, 9/25/01.
52
Row 11: Coin-operated laundries. From U.S. Census,
www.census.gov/epcd/ec97/NY000_81.HTM#N812
Row 12: Linen Services. Data from http://www.census.gov/epcd/ec97/ny/NY000_81.HTM#N812
Row 13–15: Hotel/Motel. Our estimates are derived from U.S. Census data
http://www.census.gov/epcd/ec97/ny/NY000_81.HTM#N812, sequentially adjusted to exclude
the smallest establishments and to use estimated fractions with laundries, and with restaurants.
These values are suggestive, but not authoritative. No more definitive numbers were found.
Row 16: K-12 Schools. Taken from number of public schools, from
http://nces.ed.gov/pubs2001/digest/dt098.htm for elementary schools and
http://nces.ed.gov/pubs2001/digest/dt099.html for secondary schools.
Row 17–18: Health Clubs. The upper row is all health clubs/fitness centers (NAICS 71394), from
http://www.census.gov/epcd/ec97/ny/NY000_71.HTM#N713, while the lower row is an
estimate of the fraction with real indoor swimming pools.
Row 19: Fast-food Restaurants. From http://www.restaurant.org/research/state_stats.cfm. Fast-food
percent of total assumed to be the same as national, 47%.31
Row 20–22: Prisons. From 73 correction facilities www.docs.state.ny.us/faclist, multiplied by guess of
number of separate heat pump water heater opportunities per prison.
Row 13: Health Care and Assisted Living. Two estimates were found. The US Census estimate, from
www.census.gov/epcd/ec97/NY000_81.HTM#N812, is 3487 sites, but Dr. Vera Prosper, NY
State OFA, finds 527 licensed facilities (email of September 28)
Row 23: K-12 Schools with Locker Rooms. From the number of public schools with pools plus ¼
(estimate) of the non-public secondary schools.
Row 24: K-12 Schools with Swimming Pools. Estimate from personal communication, from Dave
Clapp, NYS Ed. Facilities.
31 Personal communication from Robert Ebbins, National Restaurant Association, 9/25/01.
53
Row 25: College Dorms. Data from census of private colleges, http://www.college-guide-
nys.org/maps/nys.html. The State University of NY has 64 campuses, and the City University
of NY has 19 campuses in the 5 boroughs. We assumed 5 dorms/private college + 10/state
college and one each from the CUNY campus, with hope that errors will compensate.
Row 26: Highway Rest Areas. We were unable to find a compilation, so set a “likely upper bound.”
Probably overestimates by a factor of 2. Opportunity suggested by interviewee.
Row 27: Military Base Housing. Set to zero by assumption that this population would be difficult to
serve with a NYSERDA program.
Row 28: Light Industrial Processing. Unknown. Excluded from analysis of “commercial sector”
opportunities, but listed as suggestion from interviewee.
Columns:
Column A: The market or industry which would apply commercial-scale heat pump water heaters. To the
extent feasible, column 1 is organized as the target industry would see itself. For example, we
differentiate “restaurants” into “fast-food” and “full-service.”
Column B: The principal end uses or applications within the market of column 1. In the case hotels and
motels, we recognize multiple principal applications, so more than one row is allocated.
Column C: Auxiliary end uses within the building, such as lavatories. By themselves, these applications
might or might not justify a residential or larger heat pump water heater, but they are
subordinate to the major market within the building type.
Column D: Priority suggested by ACEEE. This is based on the scoring in column E. However, it also
incorporates other factors. One example of this is the high priority (2) assigned to coin-
operated laundries by the Federal Technology Alert (FEMP 1997). The score (Column E) for
this market is relatively low, reflecting the experiences of the interviewees.
Column E: Score calculated from interviewee responses. The score combines XXX elements weighted by
the values in rows 4 and 5, discussed below.
54
Column F: Ranked by Interviewees is an integer value scaled from 1 – 3 reflecting the average value
assigned by the interviewees. Rounding to integer values limits the precision of the values in
Column E. This was intentionally done to reflect uncertainties expressed by most interviewees.
Column G: Load Flatness. This is the contractor’s estimate of the load shape. The more hours per day that
the application calls for water heating, the smaller the required storage for a given heat pump
capacity. Flatter loads can be met more economically.
Column H: HW and A/C Coincidence. The best applications need hot water and spot air conditioning at the
same time. An example might be a restaurant kitchen dishwashing station, where the air
conditioning and dehumidification will be valued whenever dishwashing is using hot water.
Poor coincidence (and in this case, poor load flatness) would be represented by a kitchen that
only used hot water for hand-washing (small amounts) and daily wash-down (large amounts).
This might need 14-hour cooling in the cooking area, but use the vast majority of its water
during a single hour.
Column I: NY Installation Potential. Where available, an estimate of the number of opportunities for heat
pump water heater installation. No effort has been made to partition these estimates between
sites with access to natural gas and those without. The data were gathered from numerous
sources, as indicated in the comments on the spreadsheet cells.
Column J: Log (base 10) of NY Installation Potential. This transformation just makes the scale of this
parameter commensurable with the scale of the others. It also reflects our judgment that the
value of this parameter is to differentiate very large applications from very small ones.
Knowing that one application is in the range of 500 – 1000 units and another is between
19,000 and 21,000 is important, but it matters less if the latter number is actually 19,253 or
some similar number.
55
56
APPENDIX 5: HPWHS AND PEAK ELECTRICITY DEMAND32
Peak system demand is a key parameter for planning the power system. Estimating the impact on system
demand of large numbers of commercial heat pump water heaters would require relatively sophisticated
analysis that includes data on present methods of providing service water heating for different market
segments. As an alternative, this attachment illustrates the analysis pathways. As shown in Figure A5-1, the
results will vary with water heating alternative energy sources and their controls.
Figure A5-1. Analysis Framework for Evaluating HPWH Impact on System Peak Demand. Per Installation Impact Depends on Whether the Space Served Is Air Conditioned, the Alternative Source of Water Heating Energy, and the Pattern of Water Use (Relative to
Storage). SHW Means Service Hot Water.
Is the space air-conditioned?
NoHPWH will probably add to peak
Yes
Is SHW produced by fossil fuel?
Yes
NoThen SHW is elec. resistance
Is SHW on a time clock (no peak draw)?
Modest effect, depends on efficiency of A/C & HPWH
No
Roughly 2.5-fold peak reduction
Yes
Add a bit to peak unlessstorage is large relative to use
If a heat pump water heater is to provide service, including air conditioning, it may add to peak demand (if
it is in use during system demand peaks, typically hot summer afternoon and evening hours). The per site
demand will be roughly:
57
32 This attachment is drawn from a letter from H. Sachs to L. Kokkinides, September 17, 2001/
Demand (kW) = Water heating capacity (Btuh)
COP * 3412 (Btuh/kW)
Of course, system demand will be less than the unit demand, unless all the heat pumps in all installations
are running at the same instant. The reduction factor is called load diversity.
The second major analytical factor is how the facility would otherwise heat water. If its alternative is using
fossil fuel (natural gas, propane, or fuel oil), then any electricity used for water heating during peak times
will add to peak demand, regardless how efficiently it is done. On the other hand, if the alternative water
heating method is resistive electric heating, then a heat pump water heater will reduce unit demand
proportionally to the COP (typically reduce demand by 2/3, to 1/3 the demand of a resistive system). On
the other hand, if the electric resistance system is on a time clock that locks out water heating during peak
times, and if the HPWH were not demand limited, then the HPWH conceivably would add to peak demand.
For a given installation, the likely result ranges from adding to peak requirements (alternative fuel is fossil;
space is not air conditioned) to a significant peak reduction (factor of 2.5, if the space was air conditioned,
used resistance water heating, and did not have a mechanism to limit peak power draw.
Overall, the potential impacts on peak power demand are modest, since there are relatively few commercial
facilities for which water heating is a major energy use. These would include laundries, hotels, and full-
service restaurants. For other types of buildings, service hot water, although it may represent the fourth
largest load, is lower than HVAC and lighting uses.
58
APPENDIX 6: 2002 PERFORMANCE STANDARD LANGUAGE
2002 DRAFT
STANDARD FOR
COMMERCIAL ELECTRIC AMBIENT AIR-SOURCE HEAT PUMP WATER HEATERS
Developed for NYSERDA by Caneta Research, Inc., under contract with the American Council for
an Energy-Efficient Economy
(NYSERDA Project 6299)
59
PREFACE
This is a draft of a performance Standard for ambient air-source heat pump water heaters with
input power in excess of 6 kW. These units would be applied in commercial and institutional
establishments.
The method of test is ASHRAE Standard 118.1 - 2001. Method of Testing for Rating Commercial
Gas, Electric and Oil Service Water Heating Equipment. The performance standard has been
modeled on those for other unitary air conditioning and heat pump equipment by Air-conditioning
and Refrigeration Institute (ARI), the Gas Appliance Manufacturers Association (GAMA) or similar
organization. The draft will be submitted to not less than one of these organizations (GAMA or
ARI). The goal would have the standard accepted/adopted after the deliberations of an
Engineering Committee drawn from manufacturers of the covered products.
60
TABLE OF CONTENTS
SECTION PAGE
Preface …………………………………………………………………………..1
Section 1. Purpose …………………………………………………….……………………3
Section 2. Scope ……………………………………………………………..……………..3
Section 3 Definitions and References ……………………………………………..……….3
Section 4 Test Requirements ……………………………………………………………....4
Section 5 Rating Requirements ……………………………………………………………5
Section 6. Published Ratings ……………………………………………………………….5
Section 7. Marking and Nameplate Data …………………………………………………..5
Section 8. Voluntary Conditions …………………………………………………………...5
TABLES
Table 1. Operating Conditions for Standard Rating Tests … ………… ………………… 5
61
Standard for Commercial Electric Ambient Air-Source Heat Pump
Water Heaters 1. Purpose
1.1 Purpose
The purpose of this standard is to establish
for commercial electric ambient air-source
heat pump water heater equipment:
definitions and references; test
requirements; rating requirements; minimum
data requirements for Published Ratings;
operating requirements; marking and
nameplate data; and conformance
conditions.
1.1.1 Intent
This standard is intended for the guidance of
the industry, including manufacturers,
engineers, installers, contractors and users.
1.1.2 Review and Amendment
This standard is subject to review and
amendment as technology advances.
2. Scope
2.1 Scope
This standard applies to factory
manufactured electric heat pump water
heaters in excess of 6 kW input rating and
all three-phase equipment regardless of
input.
2.1.1 Classifications
This standard applies to ambient air-source
heat pump water heaters that can be
operated without connection to a storage
tank and to heat pump water heaters that
include the use of an integral tank.
2.2 Units
The primary unit values are in foot-pound
units. The values given in brackets are in SI
(metric) units.
3. Definitions and References
3.1 Definitions
All terms in this document shall follow the
standard industry definitions in the current
edition of ASHRAE Terminology of Heating,
Ventilation, Air-conditioning and
Refrigeration, unless otherwise defined in
this section.
Coefficient of Performance(COP) - A ratio
of the water heating capacity in Btu/h (kW),
to the power input in (kW), at any given set
of rating conditions.
Standard Coefficient of Performance - The coefficient of performance at Standard
Rating Conditions.
Cooling capacity - the capacity associated
with the change in air enthalpy Btu/h (kW).
Water heating capacity - the capacity
associated with the change in temperature
62
of the water passing through the heat pump
water heater, Btu/h (kW).
Ambient Air-Source Heat Pump Water Heater - a device using the vapor
compression cycle to transfer heat from the
ambient air surrounding it to heat potable
water, including all necessary ancillary
equipment such as fan/blower, pump,
integral storage tank, piping and controls.
Heat pump water heater with integral tank - a heat pump water heater that
includes a hot water storage tank specified
and available from, the heat pump
manufacturer.
Heat pump water heater without tank - means a heat pump that is not supplied with
a specific water storage tank.
Ambient air - means air from the space
where the heat pump is located and is the
heat source for the heat pump water heater.
Published rating - A statement of the
assigned values of those performance
characteristics under stated Rated
Conditions by which a unit may be chosen to
fit its application. These values apply to all
units of like nominal size and type produced
by the same manufacturer. As used herein,
the term Published Rating includes the
rating of all performance characteristics
shown on the unit or published in
specification advertising, or other literature
controlled by the manufacturer, at stated
Rating Conditions.
Application Rating - A rating based on
tests performed at Application rating
conditions (other than Standard Rating
Conditions). <<out of alphabetical order…
Standard rating - A rating based on tests
performed at Standard Rating Conditions.
Rating conditions - Any set of operating
conditions under which a single level of
performance results and which causes only
that level of performance to occur.
"Shall" or "Should" - "Shall" or "Should"
shall be interpreted as follows:
"Shall"- where "shall" or "shall not" is
used for a provision specified, that
provision is mandatory if compliance with
the standard is claimed.
"Should" - where "should" is used to
indicate provisions which are not
mandatory but which are desirable as
good practice.
3.2 References
Listed here are all standards, handbooks
and other publications essential to the
formation and implementation of the
Standard. All references in this clause are
considered as part of the Standard.
63
ASHRAE* Standard
118.1-2001
Method of Testing for Rating Commercial
Gas, Electric and Oil Service Water Heating
Equipment.
*American Society of Heating, Refrigerating,
and Air-conditioning Engineers, Inc., 1791
Tullie Circle N.E., Atlanta, Georgia 30329,
U.S.A.
4. Test Requirements
4.1 Test Requirements
Standard Ratings shall be established at the
Standard Rating Conditions specified in
clause 4.2 and 4.3. Standard Ratings shall
be verified by tests conducted in accordance
with ASHRAE 118.1-2001
4.2 Standard Water Heating Capacity
Rating
Table 1 indicates the operating conditions
for Standard Water Heating Rating tests to
determine values of standard water heating
capacity.
4.3 Standard Ratings
Table 1 indicates the operating conditions
for Standard Cooling Rating tests. Standard
Cooling Ratings shall be net values,
including the effects of circulating fan heat.
Standard input ratings shall be the total
power input to the compressor(s) and fan
plus controls and other items (such as
onboard pumps) included as part of the unit
model number. Units not supplied with a
water pump are to include pump power input
as per ASHRAE Standard 118.1 Clause 7.
4.4 Electrical Conditions
Standard rating tests shall be performed at
the nameplate rated voltage and frequency.
For units with dual nameplate voltage
ratings, standard rating tests shall be
performed at both voltages, or at the lower
voltage if only a single rating is to be
published.
4.5 Equipment
The filter and any other grilles, deflecting
vanes, fittings and other Standard
equipment of the heat pump water heater
shall be in place during all tests, unless
otherwise specified in the manufacturers
instructions to the user.
4.6 Air Flow Rate
Heat pump airflow rate shall be that
specified by the manufacturer where the fan
drive is adjustable. Where non-adjustable, it
shall be the airflow rate inherent in the unit
when operated with all of the resistance
elements (i.e., inlets, louvers, any ductwork
or attachments) considered by manufacturer
to be normal installation practice. Once
established, the evaporator air circuit shall
remain unchanged throughout all tests,
unless automatic adjustment of airflow rate
by system function is made.
4.7 Water Flow Rate
Heat pump water heater flow rate shall be
that specified by the manufacturer. If a
64
range of flow rates are provided use the
minimum value for the tests.
5. Rating Requirements
5.1 Rating Requirements
Standard ratings for water heating capacity
and total cooling capacity shall be published.
Power input ratings shall be expressed in
increments or multiples of 500 W.
5.2 Values of Standard Capacity
Ratings
Capacity ratings are to be expressed in
multiples of 1000 Btu/h for ratings in range
up to 135,000 Btu/h; in multiples of 2000
Btu/h for ratings in range from 135,000 Btu/h
to 400,000 Btu/h; and in multiples of 5000
Btu/h for ratings in range above 400,000
Btu/h.
5.3 Values of Coefficient of
Performance
Standard measures of COP, whenever
published, for water heating shall be
expressed in multiples of 0.1.
5.4 Application Ratings
Ratings at other than Standard Conditions in
Table 1 may be published as Application
ratings, and shall be based on data
determined by methods prescribed in
Clause 4.1 and their values expressed as
specified in Clauses 5.1, 5.2 and 5.3.
5.5 Tolerances
To comply with this Standard, measured test
results shall not be less than 95% of the
Published Rating for COP and capacity and
shall not exceed 105% of Published Ratings
for power input.
6. Published Ratings
Published ratings shall include all standard
ratings.
Claims to ratings within the scope of this
standard shall include wording “Rated in
accordance with _________ standard
_________.”
Claims to ratings outside scope of this
standard shall include wording “Outside
scope of ___________ standard
__________.”
Application ratings shall include a statement
of the conditions at which the application
ratings apply.
Total water heating capacity and total
cooling capacity used in published
specifications, literature or advertising,
controlled by the manufacturer and rated
under this standard shall be expressed in
Btu/h (W)
7. Marking and Nameplate Data
7.1 Marking and Nameplate Data
As a minimum, the nameplate shall display
the manufacturer's name, model designation
and electrical characteristics.
65
8. Voluntary Conditions
8.1 Conformance
While conformance with this Standard is
voluntary, conformance shall not be claimed
or implied for equipment within its Purpose
and Scope unless such claims meet all the
requirements of this standard.
Table 1 . Operating Conditions for Standard Rating Tests.
Evaporator Entering Air Temperature in oF (oC)
Condenser Entering Water Temperature in oF (oC)
DRY-BULB Wet Bulb 80 (26.7) 67 (19.4) 55 (12.8)
80 (26.7) 67 (19.4) 110 (43.3)
66
APPENDIX 7: AVAILABLE PERFORMANCE DATA FOR COMMERCIAL HPWHS
REVIEW OF SIZING GUIDELINES AND PRODUCT LITERATURE
PREPARED FOR: AMERICAN COUNCIL FOR AN ENERGY EFFICIENT ECONOMY 1001 Connecticut Avenue N.W.
Suite 801
Washington, DC
U.S.A. 30036
Attn: Dr. Harvey Sachs
Director, Appliances, Buildings and Equipment
Prepared by: Caneta Research Inc.
7145 West Credit Avenue
Suite 102, Building 2
Mississauga, Ontario
L5N 6J7
67
May, 2002
1. Introduction
The purpose of this task was to contact heat pump water heater (HPWH) Manufacturer's for equipment
performance data on their commercial units and to review sizing guidelines for commercial applications.
Seven manufacturers were contacted with limited success. Only one manufacturer provided information on
their HPWHs. The other manufacturers either did not respond, did not provide any information or are no
longer manufacturing HPWHs. The manufacturer who responded did not have sizing guidelines that could
be contributed to the project. DEC (no longer manufactures HPWHs) indicated that unit sizing was done on
a case-by-case basis.
A review of the literature identified preliminary sizing guidelines for both the HPWH and the storage tank.
The consensus from the literature review indicates that HPWH sizing should be based on optimizing the
project economics, resulting in a balance of heat pump, supplemental (i.e.: electric resistance) and storage
capacity.
2. Manufacturer Information
A total of seven air-source heat pump water heater manufacturers were contacted for equipment
performance data (water heating efficiency/capacity, cooling capacity from evaporator and rating
conditions) and equipment sizing guidelines. It was also hoped that performance data at off-design
conditions could be obtained to assist in the energy calculations necessary for the economic evaluation. The
results of the manufacturer contacts are summarized in Table 2.1.
Only one manufacturer (ECR International) provided information on their HPWHs that could be used as
part of this study. This was limited to hot water capacity, cooling capacity and hot water heating COP. One
company no longer manufacturers HPWHs, another company's phone number is no longer in service and
no new contact information could be identified on the internet. Three companies did not respond to our
requests.
68
Table 2.1. Manufacturer Contacts. Manufacturer Contact Person Contact
Information Response
Nyle Specialty
Products
Geoffry Clarke [email protected] No information provided.
Colmac Coil
Manufacturing
Joel Lewinsohn (509)684-2595 No response
Crispaire Corp.—
E-Tech Division,
Now E-Tech Division,
Applied Energy
Recovery Systems,
Inc.
Titu Doctor (770)453-9323
AER:
(770)734-9696,
x109
No response
DEC International—
Therma-Stor Products
Bernie
Mittlestaedt
(608)222-5301
No longer manufactures
HPWHs. Sizing was done on
a case-by-case basis.
Paul Mueller Co. Richard Steimel (800)683-5537 No response
Wallace Energy
Systems
Joe
Pendergrass
(404)534-5971 Phone no longer in service.
Web search could not identify
new contact info.
Enviromaster
International—ECR
International
Carl Mayer [email protected] Residential 50 gal. capacity
unit only.
3. Existing Sizing Guidelines
A number of references that discuss sizing heat pump water heaters were identified and reviewed for the
possibility of incorporation in the life-cycle costing tool. The general theme in these references is that due
to high capital costs associated with HPWHs, a balance is required between installed costs of the heat pump
unit and energy savings.
Both the EPRI references summarized below suggest that it is better to under-size the HPWH and use a
combination of storage capacity and electric resistance supplemental capacity to meet the peak demands.
This increases the run-time of the heat pump and improves the cost effectiveness of the system. The
optimum sizing will depend on the daily hot water profile and local utility rates.
69
ASHRAE Handbook
The 1999 ASHRAE Applications Handbook [1] briefly discusses refrigerant-based water heaters such as
HPWHs. There is little useful information on sizing these systems, except that conventional sizing methods
for service hot water systems cannot be used for these systems due to output variations with operating
conditions. The handbook does go on to recommend that computer software should be used, although none
are recommended by name. It also recommends the heat pump and storage capacity be selected to achieve
high daily run times and balance operating and capital costs.
FEMP - Federal Technology Alert
The Federal Energy Management Program produced a Federal Technology Alert [2] entitled Commercial
Heat Pump Water Heaters which describes the technology, the type of systems available, equipment
available and manufacturer information. A simple sizing procedure is outlined based on the assumption that
the HPWH provides 100 percent of the water heating. The heat pump capacity is selected to provide the
entire day's hot water requirements during the time that cooling is required in the space. The capacity of the
storage tank is then selected to store sufficient hot water to meet hourly peaks in hot water demand.
This sizing strategy ignores the standby losses from the tank and assumes that no supplemental heating is
required. By ignoring the possibility of using supplemental heating to reduce installed capacity, this sizing
method does not necessarily identify the most cost effective heat pump capacity.
EPRI Fact Sheet
The Electric Power Research Institute produced a Commercial HPWH fact sheet [3], which recommended
that the water heating capacity of the heat pump be no larger than 7,000 Btu/hr for every 100 gallons per
day of hot water consumption. This assumes an 80°F water temperature rise, which translates into a daily
run time of 8.5 hours per day. No guidelines are provided to size the storage tank, however, once the water
heating capacity is known the storage capacity can be chosen based on the peak hot water loads.
EPRI HPWH Applications Manual
The Electric Power Research Institute published a Commercial HPWH applications manual [4]. The
manual provides some non-specific guidelines for sizing the HPWH. The design guideline chapter states
that unlike conventional water heating equipment, HPWH capacity is dependant on a variety of conditions
(entering water temperature, air dry bulb and wet bulb temperatures) and rated capacity cannot be used for
sizing purposes.
70
It goes on to recommend that when sizing these systems, a balance must be struck between maximizing the
energy savings and minimizing the installed cost and consequently the cost effectiveness. A HPWH sized
to meet the entire hot water load will be expensive and a significant portion of the capacity will not be used
to its potential. The HPWH should not be sized to meet 100% of the hot water load.
Guidelines for sizing tanks, based on a procedure developed from Hawaiian installations, recommended
that the tanks should hold the capacity for 1.5 to 2.5 hours of heat pump output. Based on a run time versus
storage volume plot provided in the EPRI manual (Figure 4-1), 2 hours of heat pump output should be
selected for an 80°F water temperature rise.
4. Results
The lack of manufacturer product literature collected in this task will not affect the economic screening tool
planned in Task 5. Instead of selecting a specific HPWH, the user will input the hot water heater capacity,
air cooling capacity and the heat pump COP at the rating conditions developed in the standard development
portion of this project.
Heat pump performance at off-design conditions will be extremely important for estimating energy
consumption of the heat pump water heater. The water temperature in the storage tank will vary with time,
which will affect the heat pump performance. The heat pump COP and capacity will be higher at lower
entering water temperatures. Two sources have been identified to implement performance at off-design
conditions. These include the DOE 2.1E Manual[5] and a report prepared by Oak Ridge National
Laboratory[6].
The sizing of the heat pump unit will be specific to each application (hot water draw profile, utility rates
and coincident cooling requirements). The preliminary sizing guidelines identified in Section 3 will provide
default capacities (HPWH, electric resistance and storage volume) for the screening tool software, but the
user will be allowed to vary these inputs to identify the most cost-effective HPWH design for the given
situation.
5. References
1. ASHRAE. 1999. "1999 ASHRAE Handbook - HVAC Applications". American Society of Heating,
Refrigerating and Air-conditioning Engineers. Atlanta, GA.
71
2. EPRI. 1993. Commercial Heat Pump Water Heaters - Fact Sheet. Electric Power Research Institute.
Palo Alto, California.
3. Federal Energy Management Program. 1997. Commercial Heat Pump Water Heaters - Federal
Technology Alert. U.S. Department of Energy.
4. Shedd and Abrams. 1990. Commercial Heat Pump Water Heaters Applications Handbook. Electric
Power Research Institute. Palo Alto, California.
5. Winkelmann, et. al. 1994. DOE-2 Supplement - Version 2.1E. Lawrence Berkeley Laboratory.
Berkeley, CA.
6. Zimmerman, K. 1986. Heat Pump Water Heater Laboratory Test and Design Model Validation. Oak
Ridge National Laboratory. Oak Ridge, TN.
72
APPENDIX 8
HEAT PUMP WATER HEATER PERFORMANCE IN A RESTAURANT: MONITORING AND SIMULATION RESULTS FROM THE GENEVA
LAKEFRONT HOTEL, GENEVA, NY
Completed as Part of
COMMERCIAL HEAT PUMP WATER HEATERS FOR THE “NEW YORK ENERGY $MART” REGION
30 June, 2002
Submitted to:
American Council for an Energy Efficient Economy 1001 Connecticut Ave NY, Suite 801
Washington, DC 20036
and:
New York State Energy Research and Development Authority 17 Columbia Circle
Albany, NY 12203-6399
Submitted by:
Hugh I. Henderson, Jr., P.E. Daniel E. Ciolkosz, PhD.
Adam C. Walburger
CDH Energy Corp. P.O. Box 641
Cazenovia, NY 13035 (315) 655-1063
i
EXECUTIVE SUMMARY Many commercial facilities are promising applications for Heat Pump Water Heater (HPWH) units. Hotels and commercial kitchens are two especially promising building types with substantial hot water loads. This field test capitalized on existing data acquisition equipment that was installed at a full-service hotel in Geneva, New York. This facility was built in 1996 with a geothermal heat pump space conditioning system. It also uses HPWHs coupled to the geothermal loop to meet the facility’s hot water needs. Monitoring equipment had previously been installed to collect detailed system performance at this site as part of a field monitoring project. This test resumed monitoring at the site to quantify total hot water loads in the hotel facility and confirm proper operation of this unique water source HPWH (WS-HPWH) system. We also added additional instrumentation to sub-meter the hot water load in the hotel’s kitchen – which was typical of commercial kitchens found in stand-alone restaurants and other similar applications in New York State. These measured data were used to simulate the performance of a more conventional air source HPWH (AS-HPWH) in this application. Data were collected at 5-minute intervals from March through May 2002. The data were used to assess the performance of the existing WS-HPWH system as well as to determine the potential for using an AS-HPWH for just the kitchen hot water loads. Geothermal WS-HPWH Performance The WS-HPWHs at the hotel operated with an average COP of 2.4, which was about one third lower than expectations based on manufacturers data. The discrepancy may have been due to poor performance of one of the four heat pumps or problems with sensor placement. After accounting for standby losses and other system effects, the COP based on the delivered hot water energy was 1.8. System losses were shown to equal an average of 19 kW (65.4Mbtu/h), or about 25% of the heat input to the system. The water heating system continued to suffer from low supply water temperatures during the early morning hours, as was previously observed during field monitoring in 1997 and 1998. While several plumbing changes have been implemented by the hotel over the past few months, water temperatures still dropped as low as 90°F on mornings with high occupancy. Based on our observations and measurements of system performance, we believe the best way to solve the capacity shortfall is to put an instantaneous gas-fired hot water heater in the hot water supply line to provide the necessary capacity boost required during the high load periods. We estimate that a 300 MBtu/h heater would allow the system to supply 125°F water for all but 2 hours of the year. The HPWH system could still efficiently supply hot water and extract heat from the geothermal loop so that loop temperatures will be modest and space cooling efficiency will remain high. The gas-fired booster would use an estimated 2,621 therms per year at the cost of $1,310/yr.
ii
Simulated AS-HPWH Performance for the Kitchen The kitchen hot water loads were estimated to be about 1,980 gallons per day, or about 32% of the total facility load. These hot water use data – along with measurements of space conditions in the kitchen – were used to simulate the performance of an AS-HPWH. These data were used to develop a full-year analysis of system energy use and operating costs using typical year weather data. The analysis predicted the annual operating costs of the AS-HPWH system, and compared it to conventional gas and electric water heating technologies for Geneva and the New York Metro area using appropriate weather and utility costs. The benefit or penalty of the cooling provided by the AS-HPWH was considered in the analysis. The annual average simulated COP of the AS-HPWH was 3.09 to provide hot water for the kitchen. System losses were assumed to be a similar percentage as was observed for the overall system at Geneva. On average the HPWH was predicted to provide 34.7 Mbtu/h of “free” cooling in the kitchen zone. Based on observations and measurements of space conditions in the kitchen, the cooling from the AS-HPWH reduced kitchen cooling loads on the warmest days of the year, since the space thermostat set point was set fairly high. The space-heating penalty was also demonstrated to be small because of the high internal loads in this space. The economic analysis indicated that the AS-HPWH would cost $3,250/yr to operate the site, assuming only a $94 net space-conditioning benefit. The predicted operating cost for conventional systems to serve the same loads is $3,600/yr for a gas water heater or $10,200/yr for an electric resistance water heater. Simulating the system with New York City weather data and utility rates gives similar results, but with lower energy use and slightly higher operating costs. Overall, the data collected for the kitchen area confirmed that this application is highly suitable for an air source HPWH. The hot water load for this typical commercial kitchen was about 1,980 gallons/day. The measured space temperatures in the kitchen confirmed that the internal loads meant that space heating was rarely required, so that the “free” cooling provided by the heat pump rarely was rarely a penalty.
iii
CONTENTS Introduction ...........................................................................................................................1
Background ........................................................................................................................1
Field Demonstration of HPWHs...........................................................................................1
Objective of Study ..............................................................................................................2
Site Description ..................................................................................................................3
Data Collection.......................................................................................................................6
Existing Heat Pump Water Heater Analysis ..........................................................................6
Kitchen Space Conditions and Hot Water Use.......................................................................7
Flow Meter Correction ........................................................................................................9
Measured Results – WS-HPWH............................................................................................11
Total Facility Hot Water Use .............................................................................................11
Heat Pump Performance ....................................................................................................12
Ground Loop Heat Exchanger Performance........................................................................16
Measured Results – Kitchen Hot Water Use...........................................................................18
Predicting AS-HPWH Performance .......................................................................................20
Simulation Approach and Assumptions ..............................................................................20
Simulation Results ............................................................................................................21
Comparing System Economics...........................................................................................22
Conclusions .........................................................................................................................25
Appendix A – Determination of Kitchen Hot Water Use from Temperature and Flow Data ….A-1
Appendix B – Datalogger Wiring and Programming Information ……………………………..B-1
Appendix C – Calibration of Flowmeter ……………………………………………………….C-1
Appendix D – Site Experiences With Present Heat Pump Water Heating System ….……...….D-1
iv
FIGURES Figure 1. Geneva Lakefront Hotel and WS-HPWH System.......................................................3
Figure 2. WS-HPWH Schematic .............................................................................................4
Figure 3. Photos of Commercial Kitchen at Geneva Lakefront Hotel.........................................5
Figure 4. Heat Pump Water Heater System Diagram, Showing Monitored Points.......................6
Figure 5. Kitchen Layout, With Locations of Monitored Points.................................................8
Figure 6. Installation of Temperature Sensor on Sink Hot Water Line .......................................9
Figure 7. Diagram of Transit Time Meter Installation. ............................................................10
Figure 8. Calibration of Flowmeter (Onicon) with correct flow values (Transit Time). .............10
Figure 9. Trends in Hot Water Temperatures Supplied to Facility ...........................................11
Figure 10. Building Hot Water Use Trends............................................................................12
Figure 11. WS-HPWH Coefficient of Performance (HP COP)................................................13
Figure 12. Heat Pump COP vs Delta T (DHW inlet minus Loop inlet).....................................14
Figure 13. Comparison of Rated to Measured COP of Heat Pumps .........................................14
Figure 14. Build ing Domestic Hot Water System Performance...............................................15
Figure 15. Shade Plot of Heat Pump Status............................................................................16
Figure 16. Geothermal Ground Loop Temperatures and Flow Rate. ........................................17
Figure 17. Kitchen Hot Water Use, With Daily Average.........................................................18
Figure 18. Hot Water Use Profile for Kitchen and Entire Building. .........................................19
Figure 19. Booster Heater Hourly kW, with Daily Average ....................................................19
Figure 20. Trends of Daily Average Outdoor and Indoor Conditions .......................................21
Figure 21. Results of Calculation of AS-HPWH Performance (Rochester TMY)......................22
v
TABLES Table 1. Monitored Data Points – Campbell Datalogger ...........................................................7
Table 2. Monitored Data Points – Portable Dataloggers............................................................8
Table 3. One-Time and Short-Period Measurements.................................................................9
Table 4. WS-HPWH Performance Summary .........................................................................16
Table 5. Assumptions for AS-HPWH Performance Calculations .............................................20
Table 6. Electricity and Gas Rates Used in Economic Analysis ...............................................23
Table 7. Comparing the Cost of Operation and Cooling Benefit of Hot Water Heaters..............24
Table 8. Summary of Operating Costs and Expected Savings..................................................24
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. 1 June 2002
INTRODUCTION
Background Heat pump water heaters (HPWH) use a vapor-compression cycle to heat water. An air source HPWH (AS-HPWH) extracts heat from the surrounding air to heat water for domestic or service water heating purposes. Water-source HPWHs (WS-HPWHs), on the other hand, extract heat from a low temperature water loop. Like all heat pumps, the refrigeration cycle for a HPWH is most efficient when the source temperature is warmest. One side effect of all HPWHs is that the source medium (either ambient air or the water loop) is cooled. Depending on the application, this cooling effect can be beneficial or can impose additional heating loads on other equipment. HPWHs have considerable promise for use in both residential and commercial applications. Residential HPWH units have been available for more than 20 years but have experienced limited success in the marketplace. A next-generation residential HPWH unit is currently being developed by EMI in Rome, New York (with support by NYSERDA). This new air source unit promises to provide a lower cost package that can be more easily applied in residential applications. Many commercial applications are promising for use of HPWH units. The Task 1 Draft Report for this project1 reviewed 13 industries and identified commercial kitchens as an especially promising application with substantial hot water loads plus an excessively warm environment. HPWH units can provide efficient water heating while also cooling (or reducing the cooling load) in these partially conditioned spaces.
Field Demonstration of HPWHs This field test capitalized on existing instrumentation and data acquisition equipment that was installed at a full-service hotel in Geneva, New York. This facility was built in 1996 with a geothermal heat pump space conditioning system. It also uses HPWHs coupled to the geothermal loop to meet the facility’s hot water needs. Monitoring equipment had previously been installed to collect detailed system performance at this site as part of a field monitoring project sponsored by the Geothermal Heat Pump Consortium2. The monitored data points and analysis also carefully evaluated the HPWH system in the previous study. This existing test site offered the opportunity to more closely examine the hot water loads imposed on the geothermal HPWH system in that application. The test site also offered the chance to separately monitor the hot water loads in the commercial kitchen at an operating facility. This report documents these additional monitoring efforts that were undertaken at the hotel.
1 Market Opportunities for Commercial-Scale Heat Pump Water Heaters in New York State, Submitted to NYSERDA by ACEEE on January 4, 2002. 2 Carlson, S.W. and A. Walburger. 1999. GeoExchange System Monitored Performance: Geneva Lakefront Hotel. Prepared for the Geothermal Heat Pump Consortium. Washington, DC.
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. 2 June 2002
Objective of Study The objectives of this field demonstration study were to: 1. Evaluate the performance of the existing WS-HPWH system at the hotel and confirm the
HPWH system still performed as expected. 2. Collect detailed data to characterize hot water loads in the hotel kitchen, 3. Collect space temperature and humidity data from the kitchen to confirm that conditions
would be favorable for a conventional AS-HPWH, 4. Use the measured hot water load and space condition data to simulate the annual
performance of a AS-HPWH in this commercial kitchen application; compare it to conventional water heating technologies.
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. 3 June 2002
Site Description The Geneva Lakefront Hotel, is a 100,000 ft2 hotel located in Geneva, NY. The building includes 149 guest rooms, a small indoor pool, conference and banquet facilities, and a full service restaurant. The hotel also includes an on-site laundry. Hot water is provided by four 10-ton WS-HPWHs, tied to a hot water circulation loop and 3,200 gallons of hot water storage (the site is more fully described in the summary report referenced earlier).
Hotel Exterior, from West
Hotel Exterior, from Northeast
WS-HPWHs and Storage Tanks
Closeup of WS-HPWH #4
Figure 1. Geneva Lakefront Hotel and WS-HPWH System
The water heating system uses four WS-HPWHs (WaterFurnace SXW-120, 10 tons each), connected to four 800-gallon storage tanks and a hot water circulation loop. A schematic of the system is given in Figure 2. The red dots on the schematic show the monitored data points, which are more fully described in the next section.
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. 4 June 2002
F H W
T H W R
T H W E
F H P W H
T H W L
W H P W H
H P 3 H P 2 H P 1H P 4
T a n k T a n k T a n k T a n k
E x p
Supp ly
R e t u r nM a k e u p
W a t e r
W a t e r
S o f t e n e r
Co ld
W a t e r t o B u i l d i n g Figure 2. WS-HPWH Schematic
The 1,500 ft2 kitchen area contains seven sinks, an automatic dishwasher, multiple cooking surfaces, ovens, and a walk-in cooler (see Figure 3). Exhaust hoods pull significant amounts of air from the zone when the kitchen is operating. Heating and cooling for the kitchen is provided by two heat pumps. The heating and cooling set points of 75°F and 80°F during the occupied periods and 50°F and 85°F at night (the occupied period is 6 am to midnight each day). One of the two heat pumps had been inadvertently been set to an “occupied heating” setpoint of 70°F during the test period. Hot water for the dishwasher is heated from the normal supply temperature of ~120°F to 180 °F by an in-line electric booster heater (Hatco C54). The capacity of the 54 kW booster heater has been reduced to one third by disabling two of the three phases of the direct resistance heating element.
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. 5 June 2002
Commercial Kitchen, from Southwest Corner
Service Sinks
Dishwasher
Booster Heater for Dishwasher
Figure 3. Photos of Commercial Kitchen at Geneva Lakefront Hotel
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. 6 June 2002
DATA COLLECTION Monitored data were collected from the site to ascertain the performance of the existing WS-HPWH system, and to assess the hot water loads and space conditions in the kitchen. This was ultimately used to predict the performance of an AS-HPWH in the restaurant of the facility.
Existing Heat Pump Water Heater Analysis A Campbell Scientific CR10X datalogger, which had been installed as part of an earlier study, was re-commissioned and used to monitor building hot water use and the operation of the building’s WS-HPWH system. The list of monitored points collected by the data logger is shown in Table 1 and in Figure 4. These data were recorded at 5-minute intervals. Data collection began on March 07, 2002, and stopped on June 06. Total building flow data were only available from March 20-25, and from April 16 to June 06.
Heat Pump Water
Heaters
To geothermal ground loop
To Building
From Building
Storage Tanks
THWE
THWL
THWR FLT
FHW
FHPWH WHPWH SWH1,2,3,4
TGR TGS
Makeup Water
Figure 4. Heat Pump Water Heater System Diagram, Showing Monitored Points
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. 7 June 2002
Table 1. Monitored Data Points – Campbell Datalogger
Data Point
Description Units Instrumentation
TGS Loop Temperature From Ground °F YSI Hermetic Thermistor TGR Loop Temperature Entering Ground °F YSI Hermetic Thermistor THWE Entering HPWH Temperature °F YSI Hermetic Thermistor
THWL Leaving HPWH Temperature °F YSI Hermetic Thermistor
THWR Recirculation Loop Return Temp. °F Mamac TE-211Z, 1000 ohm RTD FLT Total Ground Loop Flow gpm Onicon F-1200 Turbine Flow Meter FHW Hot Water Use gpm Onicon F-1100 Turbine Flow Meter FHPWH Flow through HPWHs gpm Onicon F-1100 Turbine Flow Meter WHPWH Hot Water Heat Pump Energy Use kWh Ohio Sem. WL40R w/ 1 set of CT SWH1 Hot Water Heat Pump 1 Status minutes Veris Series 900 Current Switch SWH2 Hot Water Heat Pump 2 Status minutes Veris Series 900 Current Switch SWH3 Hot Water Heat Pump 3 Status minutes Veris Series 900 Current Switch SWH4 Hot Water Heat Pump 4 Status minutes Veris Series 900 Current Switch Note – Several additional points were monitored, but are not shown here since they are not pertinent to this study. See Appendix B for a full list of points.
Kitchen Space Conditions and Hot Water Use Several portable dataloggers were installed in the kitchen to estimate water use patterns and space conditions. Table 2 lists the monitored points gathered with the portable loggers. Figure 5 shows the location of these monitored points in the kitchen. Space conditions were monitored using several HOBO Pro battery-powered dataloggers. The temperature and humidity loggers were used to assess whether space conditions in the kitchen are favorable for operation of an AS-HPWH. Other dataloggers were also installed to estimate hot water use for the kitchen. HOBO temperature loggers were mounted on the hot water supply lines near each fixture as shown in Figure 6. These data were used to determine when hot water was used by each sink as well as by the dishwasher. These data were combined with manual, one-time readings of sink and dishwasher flow rates to predict the flows. These data were aggregated to determine hot water usage patterns for the kitchen. The number of operating cycles and runtime of the dishwasher were also monitored in order to estimate hot water use. The current draw of the instantaneous or booster water heater provided yet another indication of dishwater use (since all hot water for the dishwasher passed through this device. Details of the analysis of the temperature data are given in Appendix A
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. 8 June 2002
Table 2. Monitored Data Points – Portable Dataloggers
Data Point Description Units Dataloggers Collection Period TAI_1 Kitchen Air Temp – location 1 °F HOBO T&RH Mar 7 – Jun 6 RHI_1 Kitchen RH – location 1 % HOBO T&RH Mar 7 – Jun 6 TAI_2 Kitchen Air Temp – location 2 °F HOBO T&RH Mar 7 – Jun 6 RHI_2 Kitchen RH – location 2 % HOBO T&RH Mar 7 – Jun 6 TAS Heat Pump Supply Air Temp °F HOBO T&RH Mar 20 – Jun 6 RHS Heat Pump Supply Air RH % HOBO T&RH Mar 20 – Jun 6 THW_D Hot water supply temp – dishwasher °F HOBO Ext T Mar 20 – Jun 6 THW_SA Hot water supply temp – sink A °F HOBO Ext T Mar 20 – Jun 6 THW_SB Hot water supply temp – sink B °F HOBO Ext T Mar 20 – Jun 6 THW_SC Hot water supply temp – sink C °F HOBO Ext T Mar 20 – Jun 6 THW_SD Hot water supply temp – sink D °F HOBO Ext T Mar 20 – Jun 6 THW_SE Hot water supply temp – sink E °F HOBO Ext T Apr 16 – Jun 6 THW_SF Hot water supply temp – sink F °F HOBO Ext T Apr 16 – Jun 6 SD Status of Dishwasher # of cyc Event Logger Mar 20 – May 3 DAMPS Dishwasher Current amps PS&T Elite Pro Apr 2 – Apr 16 BAMPS 54 kW Booster Heater Current amps PS&T Elite Pro Apr 16 – May 02 TAO Outdoor Air Temperature °F NCDC Mar 01 – May 29
Sink D
Sink B
Sink A
Sink F
Sink C
Sink E
SD
T H W _ D
THW_SC
THW_SB
THW_SA
THW_SD
TAI_1
RHI_1
TAS
TAI_2
RHI_2
Sink G
Figure 5. Kitchen Layout, With Locations of Monitored Points
Walk-in Freezer
Loading Dock
Stor.
Office
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. 9 June 2002
Figure 6. Installation of Temperature Sensor on Sink Hot Water Line
Several one-time or short-period measurements were taken to calibrate sensors, verify operation, and determine performance of various portions of the system. These measurements are listed in Table 3.
Table 3. One -Time and Short-Period Measurements
Description Units Equipment Reading Dishwasher water use rate Gpm Measuring Container and timer 1.42 Sink A water use rate Gpm Measuring Container and timer 5.0 Sink B water use rate Gpm Measuring Container and timer 5.0 Sink C water use rate Gpm Measuring Container and timer 1.5 Sink D water use rate Gpm Measuring Container and timer 4.0 Sink E water use rate Gpm Measuring Container and timer 2.0 Sink F water use rate Gpm Measuring Container and timer 2.0 Building Hot Water Use Gpm Polysonics Transit-Time Flowmeter Kitchen Booster Heater Power kW Tif 200A Wattprobe 16.8 Dishwasher Power Use kW Tif 200A Wattprobe 17.7
Flow Meter Correction The total flow readings from the Onicon flowmeter (point FHW in Table 1) were suspect even though a new flow meter was installed. Recent modifications to the plumbing system had affected the flow patterns at the turbine, decreasing our confidence in the output from the meter. In order to evaluate wheter the flow rate was correct, an ultrasonic transit-time flow meter was installed on the same pipe for 11 days (Apr 22 – May 3). A portable datalogger recorded the readings from
Temperature Sensor
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. 10 June 2002
the transit time meter at a time step similar to the turbine flow meter so that the two values could be directly compared. Transit time flowmeters measure flow through a pipe by measuring the speed of an acoustic signal passed through the pipe, between two sensors. Figure 7 shows an example of the installation of the transit-time flowmeter, showing sensor placement and signal processing equipment.
Flow
Signal Processing Module
Sensor Path of Signal
0-100 gpm = 4-20 mA output
4” Copper Pipe
Mounting Bar
Figure 7. Diagram of Transit Time Meter Installation.
The continuous data collected over the 11day period were correlated with multi-linear regression analysis to develop the 2nd order polynomial shown in Figure 8. The correction was applied to all the plots of FDHW shown in this report.
Transit Time vs. Onicon Readings
0 5 10 15 20 25
Onicon (gpm)
0
5
10
15
20
25
Tra
nsi
t T
ime (
gpm
)
TT = 0.689+1.215 * Onic + -0.013 * Onic 2
Figure 8. Calibration of Flowmeter (Onicon) with correct flow values (Transit Time).
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. 11 June 2002
MEASURED RESULTS – WS-HPWH This section reports the measured performance of the existing geothermal HPWH system and shows the hot water use patterns for this facility.
Total Facility Hot Water Use The hot water system provided an average of 4.31 gpm of hot water to the building at an average temperature of 123 °F. The temperature ranged from 89 to 137 °F across the period. The lowest of these temperatures occurred periodically, as shown in Figure 9 below, typically during the morning hours, when guests took their morning showers.
4 11 18 25 1 8 15 22 29 6 13 20 27 3
March April May
100
110
120
130
140
150
Bld
g H
W T
emp
(F)
80 90 100 110 120 130 140
Bldg HW Temp (F)
0
200
400
600
800
Num
ber o
f Hours
0 5 10 15 20 25
Hour of Day
80
100
120
140
160
Ave
Bld
g H
W T
emp
(F)
0 20
HW Use (GPM)
80
90
100
110
120
130
140
Bld
g H
W T
emp
(F)
Figure 9. Trends in Hot Water Temperatures Supplied to Facility
Figure 10 shows the variations in total building hot water use. Hot water use ranged as high as 27.1 gpm (average in a 5-minute interval) and averaged 4.31 gpm (6,208 gallons per day) across the monitoring period . The maximum water use rate for for an hour (22.9 gpm) occurred from 8-9 am on May 12. High flow rates tended to occur during the early to mid morning hours, corresponding to the times when guests would tend to use the showers (and temperatures would drop).
Average and +/ - 1 Std Dev
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. 12 June 2002
4 11 18 25 1 8 15 22 29 6 13 20 27
March April May
0
2000
4000
6000
8000
10000B
ldg
HW
(gp
d)
1.0 2.8 4.7 6.5 8.3 10.2 12.0
Bldg HW (gpd x 1000)
0
2
4
Num
ber
of H
ours
0 5 10 15 20 25
Hour of Day
5
10
15
Ave
Bld
g H
W (gp
m)
Figure 10. Building Hot Water Use Trends
Heat Pump Performance The Coefficient of Performance (COP = kW of heat added to water divided by kW of electricity used) averaged 2.40 during the test period (Figure 11). System COP (accounting for losses in the piping) was lower, averaging 1.86. Note that system COP only applies across a day, due to thermal storage effects of the hot water tanks.
Shows average and +/- 1 SD
Sensor Offline
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. 13 June 2002
18 25 1 8 15 22 29 6 13 20 27
March April May
0
2
4
6
HP C
OP
18 25 1 8 15 22 29 6 13 20 27
March April May
0
2
4
6
Sys
CO
P
0 5 10 15 20 25
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0
1
2
3
4
Ave
CO
P
0 20 40
HW Use (gpm)
0
1
2
3
4
5
HP C
OP
Figure 11. WS-HPWH Coefficient of Performance (HP COP)
The four heat pumps in the system did not perform equally – heat pump #1 gave a much lower COP than the other units (Figure 12). This may be due to faulty construction of the unit, although the unit was inspected, and the level of refrigerant charge was checked. One other possible cause of the readings would be faulty placement of the temperature sensor that measures heat pump temperature rise. The temperature sensor for water leaving the heat pumps is mounted immediately downstream from the input of hot water from Heat Pump #1. Thus, the flow past the sensor may not be fully mixed. As a result, the temperature sensor may be reading erroneously low when Heat pump #1 is on.
Shows average and +/- 1 SD
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. 14 June 2002
30 40 50 60 70 80 90
Heat Pump Delta T
0
1
2
3
4
5
Heat P
um
p C
OP
Figure 12. Heat Pump COP vs Delta T (DHW inlet minus Loop inlet)
The measured and rated performance of the heat pumps are compared in Figure 13. Ratings for the 10 ton units were not available, so data from the 7.5 ton unit were used instead, and fitted to a bi-quadratic equation. Measured COP is based on temperature rise and water flow measurements at the heat pumps. The measured COP is lower than the rated performance, especially when heat pump #1 is running (average ratio = 0.54). Removing points when heat pump #1 is on, and plotting the expected vs the measured COP (Figure 13, Right Side), shows that the measured COP tends to be lower by 1 to 1.5.
25 1 8 15 22 29 6 13 20 27
April May
0
2
4
6
8
Hea
t Pum
p C
OP
1 2 3 4 5 6
Expected COP
1
2
3
4
5
6
Mea
sure
d C
OP
Figure 13. Comparison of Rated to Measured COP of Heat Pumps
Rated Measured
Plot includes data only if HP #1 is off
Heat Pump #1 Off Only Heat Pump #1 Operating
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. 15 June 2002
Heat pump power and hot water energy supplied is shown as a function of hot water use in Figure 14. This plot shows the relative amount of heat lost to the piping (y intercept) versus the amount of heat in the delivered hot water. This plot shows that ”standby” losses in the system are about 19 kW. This corresponds to a 1.5°F temperature drop in the distribution loop, at the measured reciculation rate of 85 gpm3, which is consistent with observed values.
Heat Pump kW vs Bldg Hot Water Use
0 5 10 15 20 25 30
Hot Water Use (gpm)
0
20
40
HP
WH
Input P
ow
er (k
W)
Hot Water Energy vs. Bldg Hot Water
0 5 10 15 20
Hot Water Use (gpm)
0
50
1 0 0
1 5 0
Hot W
ate
r E
nerg
y (k
W)
HW = 19.16 + 6.94 * GPM
Figure 14. Building Domestic Hot Water System Performance
Figure 15 shows a shade plot of the number of heat pumps operating at the facility. Generally, at least one heat pump is always in operation, with all often operating during the period from 8 am to around 4 pm. The heat pumps are running during this period to make up for high morning usage of hot water. Some days required all four heat pumps to run until about midnight – these were probably days with high hotel occupancy, since they tend to occur on weekends. Average power use by the heat pumps is 19.5 kW, and average heat output is 48.6 kW.
3 The recirculation rate of 85 gpm corresponds to the domestic water flow rate through the heat pump water heaters.
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. 16 June 2002
# of Heat Pump Water Heaters Operating
Day (MAX/MIN = 4.00/ 0.00 kW)
March April May Jun
2002
0
2
4
6
8
10
12
14
16
18
20
22
24
Hour
of
Day
MAX
MIN
Figure 15. Shade Plot of Heat Pump Status
A summary of the performance of the WS-HPWH system is given in Table 4.
Table 4. WS-HPWH Performance Summary
Average Supply Temp 123.7 °F Min/Max Supply Temp 89.1 / 136.7 °F Average Building Hot Water Use 4.3 gpm (6208 gal/day) Average COP, heat pumps only 2.40 Average System COP1 1.80 Electricity Use/gallon of hot water 0.074 kWh/gallon
1 – System COP takes into account system heat losses, but not circulation pump power
Ground Loop Heat Exchanger Performance The water source HPWHs at the site draw heat from the building’s geothermal ground loop. Temperature and flow rates for the loop were monitored, and are shown in Figure 16. Loop temperatures and flow rates jumped in mid April, when the region experienced a brief hot spell. Temperatures and flow rates began to rise again towards the end of May, as the heat of summer began to increase the cooling load of the building.
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. 17 June 2002
Ground Loop Temperature
4 11 18 25 1 8 15 22 29 6 13 20 27 3
March April May
40
60
80
Tem
pera
ture
(F)
4 11 18 25 1 8 15 22 29 6 13 20 27 3
March April May
0
200
400
Loop
Flo
w R
ate
(gpm
)
Figure 16. Geothermal Ground Loop Temperatures and Flow Rate.
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. 18 June 2002
MEASURED RESULTS – KITCHEN HOT WATER USE This section uses the data collected in the kitchen to estimate the hot water use patterns for that portion of the facility. While we had originally hoped to directly measure kitchen water flow with an ultrasonic flow meter, the facility plumbing did not allow a direct measurement. Therefore we used indirect techniques to estimate the water use profile. The data reduction techniques used to estimate flow are described in Appendix A. Kitchen hot water use averaged 1.38 gpm (1982 gal/day), with peak flow rates as high as 14 gpm (the average in a 5-minute interval). An average of 0.33 gpm is used by the dishwasher (about 24%) with the remainder used by the sinks. The red data Figure 17 show the instantaneous flow readings over 7 weeks. The daily average hot water use rates are show as diamonds on the plot.
Calculated Hot Water GPM
15 22 29 6 13 20 27 3
April May June
2002
0
5
10
15
Wate
r U
se (
GP
M)
Figure 17. Kitchen Hot Water Use, With Daily Average.
The daily average hot water use profile for the kitchen is shown in Figure 18 along with the profile for entire hotel. Hot water use during the day (7 am-10 pm) is relatively steady, with an average of 1.82 gpm. The highest water use in an hour was 5.88 gpm, which occurred at 1 pm on May 1. The coefficient of variation (standard deviation divided by mean) of the hourly daytime readings was equal to 0.43.
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. 19 June 2002
Building and Kitchen Average Flow Profile
22: 0: 2: 4: 6: 8: 10: 12: 14: 16: 18: 20: 22: 0:
0
2
4
6
8
10
12
Flo
w (
gpm
)
Figure 18. Hot Water Use Profile for Kitchen and Entire Building.
Hot water for the dishwasher passes through an electric booster heater, which raises the water temperature from 120°F to 180°F. The instantaneous and daily average power use by the booster heater is shown in Figure 19. These data were used in the analysis described in Appendix A to predict the hot water use of the dishwasher.
Booster Heater kW
16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 1 2
April May
0
2
4
6
8
10
Hourly
Dem
and (
kW)
Figure 19. Booster Heater Hourly kW, with Daily Average
Building Average (6,208 gpd) Kitchen Average (1,982 gpd)
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. 20 June 2002
PREDICTING AS-HPWH PERFORMANCE The water heating system in this facility uses WS-HPWH since a geothermal loop was available for heat extraction. In more general commercial kitchen applications, conventional AS-HPWH systems would typically be used to provide water heating. This section uses the measured data collected for the commercial kitchen to predict the performance of a more typical AS-HPWH. A full-year simulation was driven by typical year weather data to determine the performance of an Air Source Heat pump Water Heater (AS-HPWH) at the site.
Simulation Approach and Assumptions Performance of a typical AS-HPWH at the site was simulated using measured water use and space conditions, a model of HPWH performance based on manufacturers data, and typical year hourly weather data. Using measured data from the site, indoor space humidity was calculated as a function of outdoor humidity. The indoor temperature was assumed to be constant. HPWH performance was based on manufacturer’s rated performance data for heat pump output and efficiency as a function of outlet temperature and entering air conditions. The hot water supply temperature was assumed to be 120°F, with makeup water temperatures varying according to the calculated ground temperature at a depth of 8 feet4. The model assumptions are listed in Table 5.
Table 5. Assumptions for AS-HPWH Performance Calculations
HPWH Performance Data Etech 400 Series Air Source HPWH 51,600 Btuh heating output – 3.0 COP 34,600 Btuh cooling output – 6.9 EER
Outdoor Weather Data Rochester TMY, New York TMY data
Hot Water Use 1.38 gpm average, profile from Figure 17 Indoor Air Temperature 80°F A summary of outdoor and indoor conditions measured at the site are shown in Figure 20. Indoor temperature varies somewhat, with an average of about 80°F. This high value (higher than the setpoint) implies that the kitchen heat pumps were rarely in heating mode. In fact, examination of the building’s control system records revealed that the kitchen air conditioning heat pumps operated in heating mode for an average of only 168 hours during the winter of 2001-02. Indoor absolute humidity varies linearly with outdoor absolute humidity, although the slope of the relationship changes at an outdoor humidity of about 60 grains.
4 The ground temperature was calculated using the simple approach from the NRECA GSHP design manual (pages 82-88) using data for Rochester.
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. 21 June 2002
4 11 18 25 1 8 15 22 29 6 13 20 27
March April May
50
60
70
80
90
100
TA
I (F)
4 11 18 25 1 8 15 22 29 6 13 20 27
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HU
M_I
(gr
)
4 11 18 25 1 8 15 22 29 6 13 20 27
March April May
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TA
O (F)
0 20 40 60 80 100
HUM_O (gr)
0
20
40
60
80
100
HU
M_I
(gr
)
HUM_I = 9.37 + 0.86 * HUM_O<60
HUM_I = 30.12 + 0.47 * HUM_O>60
Figure 20. Trends of Daily Average Outdoor and Indoor Conditions
Simulation Results Simulation results with Rochester TMY data are shown in Figure 21. The HPWH system heats water with an average COP of 3.09, which is higher than the measured value for the WS-HPWH, but lower than the WS-HPWH rated value. The AS-HPWH system also provides an average of 35,000 Btu/h of cooling (~3 tons) to the kitchen zone. Although some of the cooling during winter months may be a penalty, the measured space and supply air temperatures from the kitchen imply that the space conditioning heat pumps rarely operated in heating mode. The kitchen appears to be primarily heated by the cooking equipment and other appliances in the space.
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. 22 June 2002
Jan F Mar Apr MayJun Jul AugSepOct NovDec
2002 2003
0
20
40
60
80
100
TA
O (F
)Ave tao= 47.55
Jan F Mar Apr MayJun Jul AugSepOct NovDec
2002 2003
0
50
100
150
200
HU
MO
(gr
)
Ave humo= 60.21
Jan F Mar Apr MayJun Jul AugSepOct NovDec
2002 2003
2.6
2.8
3.0
3.2
3.4
3.6
Hea
ting
CO
P
Ave cop= 3.09
Jan F Mar Apr MayJun Jul AugSepOct NovDec
2002 2003
3.0E4
3.2E4
3.4E4
3.6E4
3.8E4
4.0E4
Clg
Btu
h
Ave btuh= 34654.
Figure 21. Results of Calculation of AS-HPWH Performance (Rochester TMY)
Comparing System Economics The results of the simulation were used to compare the economics of the AS-HPWH system to the current WS-HPWH system as well as other more conventional water heating systems. The annual cost of operation is calculated for the systems using calculations for two locations – one upstate location (Rochester), as well as one downstate location (New York City). Power use and output for the AS-HPWH is based on the calculations above. Power use for an electric resistance water heater is calculated assuming 95% efficiency (COP=0.95). The gas water heater efficiency was assumed to equal 80%. A system loss factor of 0.75 (heat losses in distribution lines, etc. – similar to measured values from Figure 11 above) is applied to all of the systems. Utility rates for the two locations are given in Table 6. The energy costs given in the table are annual averages (some rates vary according to time of year). When blocked rates were used, the middle block rates were assumed.
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. 23 June 2002
Table 6. Electricity and Gas Rates Used in Economic Analysis
Location Electric Rate Gas Rate Rochester RG&E SC7:
$13.661/kw $0.058/kWh
RG&E SC1: $0.456/therm (energy)1 +$0.178/therm (delivery)
New York City
ConEd SC9: $18.749/kw $0.0667/kWh
ConEd SC2: $0.456/therm (energy)1 +$0.286/therm (delivery)
1 – based on commodity gas costs from 2001 (Niagara Mohawk) Cold water temperatures for Rochester and New York City were assumed (as is described in the previous section) equal to ground temperatures at a depth of 8’. Benefit of AS-HPWH Cooling One benefit of the AS-HPWH is that it provides cooling to the space. The direct economic benefit of this cooling depends on whether or not other mechanical cooling is displaced as a result. The economic analysis is considered with two different scenarios, in order to bound the possible benefits:
a) None of the cooling from the AS-HPWH is displacing mechanical cooling, and half of the cooling must be made up for by mechanical heating (space heating COP=3.5).
b) All of the cooling from the AS-HPWH is displacing mechanical cooling (12 SEER ).
A third case is analyzed, which corresponds to the most likely performance of the AS-HPWH system at the site. Analysis of temperature data at the site indicates that the site is never in heating mode, even at outside temperatures as low as 20°F. This is most likely due to the high internal heat load from the ovens and stoves. Thus, the cooling effect of the AS-HPWH can be assumed to have no impact on space heating loads. The space does appear to go into cooling mode on afternoons when the daily outdoor air temperature rises above about 70°F. This case occurs about 47 days of the year at the site, and 86 days per year downstate. Thus, the direct economic benefit to the site is probably limited to those times. Value of cooling from the AS-HPWH is calculated assuming that the facility’s cooling system operates at a SEER of 12. Results of the economic analysis are shown in Table 7.
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. 24 June 2002
Table 7. Comparing the Cost of Operation and Cooling Benefit of Hot Water Heaters.
Rochester, New York Value of Cooling ($/yr) System Energy Usage Water
Heating Cost ($/yr)
Min Probable Max
Existing WS-HPWH 55,618 kWh/yr 4,320 - - - AS-HPWH 43,041 kWh/yr 3,343 -936 94 1,946 Electric Resistance 132,237 kWh/yr 10,197 - - - Natural Gas 5,639 therms/yr 3,576 - - - New York City Value of Cooling ($/yr) System Energy Usage Cost
($/yr) Min Probable Max
AS-HPWH 36,745 kWh/yr 3,800 -1,108 181 2,249 Electric Resistance 113,871 kWh/yr 11,701 - - - Natural Gas 4,856 therms/yr 3,952 - - - Operating costs for the AS-HPWH system are slightly lower than for the natural gas water heater, and much lower than an electric resistance hot water heater. This trend is true for both sites, although the absolute value of the costs is higher in New York City, and the energy use in New York City is lower. The AS-HPWH is less expensive to operate than the existing WS-HPWH system, although the existing system was operating significantly below its rated efficiency. The maximum possible value of the cooling is quite high, but this upper bound would only occur if the kitchen were calling for cooling every hour of the year. The minimum possible value of the cooling is actually a cost, due to the amount of heating that would be required to make up for the space cooling during winter months. Actual conditions would probably result in a modest positive value of the cooling provided to the space. Additional benefits from the AS-HPWH cooling may result from cooler (and more comfortable) conditions on days when the cooling system is not being activated, but indoor conditions are still warmer than optimum. A summary of the annual operating costs and savings (relative to electric resistance hot water heaters) is given in Table 8.
Table 8. Summary of Operating Costs and Expected Savings
Rochester, New York Hot Water System Annual Operating
Costs (probable) Savings (relative to electric resistance heater)
Existing WS-HPWH $ 4,320 $ 5,877 AS-HPWH $ 3,249 $ 6,948 Natural Gas $ 3,576 $ 6,621 New York City Hot Water System Annual Operating
Costs (probable) Savings (relative to electric resistance heater)
AS-HPWH $ 3,619 $ 8,082 Natural Gas $ 3,952 $ 7,749
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. 25 June 2002
CONCLUSIONS Operating characteristics of the test facility, a hotel and restaurant in Geneva, New York, were examined, and appear to be suitable for use of Heat Pump Water Heater technology. The existing Water-Source Heat Pump Water Heater (WS-HPWH) provided an average of 6,200 gal/day of hot water to the building, at an average COP of 2.4 for the heat pumps. This is significantly lower than the rated performance of these units. The COP dropped to an average of 1.8 when heat losses in the distribution system are taken into account. The WS-HPWH had difficulty providing hot water during periods of high load, resulting in occasional low water temperatures in the building. However, water temperatures were high most of the measured period, with an average of 124°F. Kitchen hot water was estimated to be about 1,980 gal/day (1.38 gpm). This corresponded to about 32% of the total building hot water load. Although direct measurement of flow is preferable, a good estimate of hot water use can be obtained using temperature sensors at the points of use. Analysis of data collected at the site indicates that commercial kitchens in New York State are highly suitable for use of Air Source Heat Pump Water Heaters (AS-HPWHs). Operating costs for an AS-HPWH are slightly lower than for a gas-fired water heater, and cooling is provided to the space as an added benefit. The direct economic benefit of the cooling appears to be relatively small in this climate, due to the low cooling load. Extending these results to a New York City location resulted in similar annual costs, although energy use was slightly lower and energy rates were slightly higher.
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. A-1 June, 2002
APPENDIX A – DETERMINATION OF HOT WATER USE FROM
KITCHEN TEMPERATURE AND FLOW DATA
Introduction Hot water is supplied to the building through a continuously circulating hot water loop. This design insures that hot water is always quickly available at the many points of use throughout the building. Unfortunately, this approach also makes it impractical to isolate and directly measure hot water use by the commercial kitchen. As a result, a temperature-flow approach had to be relied upon to determine the amount of hot water used in the kitchen. The temperature-flow approach consists of monitoring the temperature of the hot water supply line for each water-using appliance in the kitchen, and making one-time measurements of the hot water flow rate from each appliance. Temperature data are used to determine how often and how long hot water is used by each appliance, and flow data are used to transform these readings into hot-water-usage data.
Algorithm Calculations of hot water use are based on the following assumptions regarding the kitchen hot water:
1. Hot water is flowing if the temperature of the hot water line is steady or increasing, and is higher than ambient temperatures.
2. Flow rate at a fixture is proportional to the temperature of the hot water line (relative to the temperature of the supply water and the ambient temperature).
Translating these assumptions into a mathematical algorithm results in the following equation for water use from a fixture. FHW = K * FM * (THL-TA)/(THS-TA) Where FHW = Hot Water Flow from fixture (GPM) K = Coefficient = 1 if THL is rising or steady = 0 otherwise FM = Measured hot water flow rate for fixture (gpm, see Table A1) THL = Temperature of hot water line entering fixture (°F) TA = Ambient air temperature (°F) THS = Temperature of Hot Water Supply Loop (°F) Hot water for the dishwasher is boosted to 180°F by an in-line electric booster heater. Thus, calculations for dishwasher hot water used a value of 180 for THS, rather than the measured temperature of the hot water supply loop.
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. A-2 June, 2002
Data Collection Temperature data were gathered using Onset Hobo Pro Remote Temperature dataloggers. These loggers measured both the temperature of the hot water line (THL) and the ambient air temperature at the fixture (TA). Figure A1 shows photos of the temperature sensors installed on the sinks and the dishwasher in the kitchen.
Sink A
Dishwasher Hot Water Supply
Fixture
Sensor
Insulation (cut away view
Datalogger
Hot Water Supply
Typical Sensor Placement Detail
Sink E
Figure A1. Hot Water Temperature Sensors Installed in Kitchen
Flow data were gathered by manually measuring hot water flow, using a bucket and a stopwatch. Temperature data for the building supply loop were measured and logged by the Campbell datalogger located in the hotel’s mechanical room.
Sensor Datalogger
Sensor Datalogger
Sensor Datalogger
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. A-3 June, 2002
Results Applying the temperature-flow algorithm results in an average hot water usage rate of 1.4 gpm (April 17-June 05). Table A1shows the average flow rates calculated for each of the fixtures in the kitchen.
Table A1. Hot Water Flow Rates
Fixture Average gpm over period
Max Flow Rate of Hot Water (gpm)
Average Hot Water Flow Rate (gpm)
Sink A 0.11398 5 5 Sink B 0.21404 5 5 Sink C 0.19723 1.5 0.75 Sink D 0.27766 4 2 Sink E 0.23516 2 1 Sink F 0.00893 2 1 Dishwasher 0.33065 1.42 1.42 Total 1.37766
Sample hot water temperatures are shown for two different fixtures in Figure A2 and Figure A3, as well as the corresponding calculated hot water use. Points at which the hot water was determined to be flowing (coefficient K = 1) are shown on the figures with triangles. Note that dishwasher water temperature rises to around 180°F due to the booster heater.
6: 7: 8: 9: 10: 11: 12: 13: 14: 15: 16: 17:
27
0
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HW
Tem
p (
F)
02
4
6
810
HW
Flo
w (
Gal)
Figure A2. Hot Water Temperatures and Calculated Flow for the Dishwasher, April 27
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. A-4 June, 2002
:0 :30 :0 :30 :0 :30 :0 :30 :0 :30 :0 :30
12: 13: 14: 15: 16: 17:
020
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Tem
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02
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1012
HW
Flo
w (
Gal)
Figure A3. Hot Water Temperatures and Calculated Flow for Sink D, April 27
Resulting water flow rates for the entire kitchen are shown in Figure A4. Both 5-minute interval data and daily average data are plotted. While short-time usage rates can rise to nearly 14 gpm, daily averages tended to be no more than 2gpm.
Calculated Hot Water GPM
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April May June
0
5
10
15
Wate
r U
se (
GP
M)
Figure A4. Calculated Hot Water Use for Kitchen
Water use (temp rising) No water use
(pipe cooling)
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. A-5 June, 2002
The daily pattern of water use for the kitchen is relatively repeatable, with most water use occurring between 8am and 10pm. Figure A5 shows the average kitchen water use profile, with lines for +/- 1 standard deviation. While the average pattern is fairly steady, the standard deviation is quite high, indicating a fair amount of variation in use rate over the course of a day. Figure A6 shows the average flow profile for the kitchen, as well as the average flow profile for the entire hotel. Kitchen usage fits nicely under the building usage profile, with most of the difference attributable to guest showers (6-8am, 9-11pm) and laundry (9am-2pm).
22: 0: 2: 4: 6: 8: 10: 12: 14: 16: 18: 20: 22: 0:
0
1
2
3
4
5
Kitc
hen H
ot W
ate
r U
se (
gpm
)
Figure A5. Kitchen Hot Water Use Profile, with +/- 1 Standard Deviation
Building and Kitchen Average Flow Profile
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0
2
4
6
8
10
12
Flo
w (
gpm
)
Figure A6. Hot Water Use Flow Profile, Kitchen and Whole Building.
Building Average Kitchen Average
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. A-6 June, 2002
Analysis of Dishwasher Hot Water Use There is only one method available for estimating hot water use by the entire kitchen. However, there are four possible ways to use the measured data to calculate dishwasher hot water use. These four methods are compared in this section, to see if there is reasonable agreement between them, to provide give greater confidence in the accuracy of our calculations of water use for the entire kitchen.
Calculation Techniques Used The four calculation techniques investigated here are as follows: 1. Temperature – Flow Model. This approach uses the temperature of the hot water supply line entering the dishwasher and the published hot water use rate for the equipment to calculate water usage. This technique can also be used to estimate hot water use from the sinks in the kitchen. Details of this approach are given in Appendix A. 2. Booster Heater Current Model. This approach uses the measured current of the dishwasher booster heater along with the temperature increase of the water to calculate the hot water flow rate. The equation for this method is as follows: GPM = kW * eff * 56.8833 / (8.334 * ∆T) Where GPM = Hot Water Flow Rate (gallons per minute) kW = Booster Heater kW (derived from current measurement) eff = efficiency of booster heater (assumed 1.0) 56.8833 = Conversion – Btu/min per kW 8.334 = Conversion – Btu/gal °F ∆T = Temperature increase of water due to booster heater 3. Dishwasher Status Model. This approach uses measurements of Dishwasher Status (# of operating cycles) to estimate water use, assuming that a fairly equal amount of hot water is used each time the equipment is activated. The equation for this model is as follows: GPM = # * 1.3 Where # = number of times dishwasher was activated 1.3 = gallons of hot water used per activation 4. Dishwasher Current Model. This approach uses measurements of Dishwasher Current, and derives water use, assuming that water use is directly related to the average current draw of the dishwasher. The equation for this method is as follows:
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. A-7 June, 2002
GPM =( ID / 43.) * 1.3 Where GPM = Hot Water Flow Rate (gallons per minute) ID = Measured Dishwasher Current (amps) 43 = Dishwasher Current when on continuously 1.3 = Dishwasher Water Flow Rate when on (gallons per minute)
Results The resulting values for dishwasher water use are shown in Figure A7 (4-hourly) and Figure A9 (daily). Direct comparisons between the temperature model and the other three methods are shown in Figure A8 (4-hourly) and Figure A10 (daily). Average daily hot water use rates are about 0.5 gpm for the Temperature, Dishwasher Status, and Dishwasher Current methods, and about 1.5 gpm for the Booster Heater Current method. The methods show good agreement, with the exception of the booster heater method, which predicts hot water use rates much higher than the other three methods. These results suggest that the temperature method is in line with the Dishwasher Status, Booster Heater, and Dishwasher Current methods. While the data are not perfectly correlated, they do predict similar absolute values for water use. Thus, the temperature method appears to be reasonably robust, and can be used with confidence for estimating hot water use by the entire kitchen.
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March April May
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tem
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ture
model
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boost
er
htr
mod
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eve
nt lo
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0.0
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ash
er
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ent m
odel
Figure A7. Dishwasher Hot Water Use (gpm), Using Four Calculation Methods.
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. A-8 June, 2002
0.0 0.5 1.0 1.5
temperature model
0.0
0.5
1.0
1.5
tem
pera
ture
mod
el
0.0 0.5 1.0 1.5
temperature model
0.0
0.5
1.0
1.5
boost
er
htr
mod
el
0.0 0.5 1.0 1.5
temperature model
0.0
0.5
1.0
1.5
eve
nt lo
gger
mod
el
0.0 0.5 1.0 1.5
temperature model
0.0
0.5
1.0
1.5
dw
ash
er
curr
ent m
odel
Figure A8. Comparison of Calculation Methods to Temperature Model.
4 11 18 25 1 8 15 22 29 6 13 20 27 3
March April May
0.0
0.2
0.4
0.6
0.8
1.0
tem
pera
ture
model
4 11 18 25 1 8 15 22 29 6 13 20 27 3
March April May
0.0
0.2
0.4
0.6
0.8
1.0
boost
er
htr
mod
el
4 11 18 25 1 8 15 22 29 6 13 20 27 3
March April May
0.0
0.2
0.4
0.6
0.8
1.0
eve
nt lo
gger
model
4 11 18 25 1 8 15 22 29 6 13 20 27 3
March April May
0.0
0.2
0.4
0.6
0.8
1.0
dw
ash
er
curr
ent m
odel
Figure A9. Daily Average Hot Water Flow Rate (gpm) Using Four Calculation Methods.
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. A-9 June, 2002
0.0 0.2 0.4 0.6 0.8 1.0
temperature model
0.0
0.2
0.4
0.6
0.8
1.0
tem
pera
ture
mod
el
0.0 0.2 0.4 0.6 0.8 1.0
temperature model
0.0
0.2
0.4
0.6
0.8
1.0
boost
er
htr
mod
el
0.0 0.2 0.4 0.6 0.8 1.0
temperature model
0.0
0.2
0.4
0.6
0.8
1.0
eve
nt lo
gger
mod
el
0.0 0.2 0.4 0.6 0.8 1.0
temperature model
0.0
0.2
0.4
0.6
0.8
1.0
dw
ash
er
curr
ent m
odel
Figure A10. Comparison of Daily Calculations to Temperature Model.
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. B-1 June, 2002
APPENDIX B – DATALOGGER WIRING AND PROGRAMMING
INFORMATION
Overview This appendix gives the wiring and programming information for the Campbell Datalogger, which was re-commissioned for use in this study. The logger had been installed at the site for a previous study, so its adaptation for the current project allowed monitoring of many data points at a relatively low cost.
Re-Commissioning Process The datalogger was still in place at the site, with all sensors still intact. Two of the flow meters had stopped working, but the rest of the system was in good working order. The re-commissioning process consisted of double checking the equipment and sensors, replacing the faulty flowmeters, and adding a power transducer to measure the power used by Heat Pump #4. Table B1 lists the added sensors.
Table B1. Sensors Added or Replaced During Re-Commissioning
Data Point
Sensor Datalogger Connection Point
Comments
FHW Onicon F-1100 Single Turbine Flow Meter, 3” Pipe
Switch Closure Module #0, Input #11
Replaced malfunctioning sensor
FHPWH Onicon F-1100 Single Turbine Flow Meter, 4” Pipe
Switch Closure Module #0, Input #2
Replaced malfunctioning sensor
WHW4 (Replaces WPP)
Ohio Semitronics WL40R Multiplexer Module #1, Input #7
New data point – measures power to Heat Pump #4
1 – Sensor signal was moved to P1 on April 16, 2002. A Phone multiplexer was also added to the system, to allow modem access to the datalogger through the building’s DDC phone line.
System Description The data acquisition system or DAS was installed in the Geneva Lakefront Hotel on May 22, 1997. The DAS was designed to measure and record temperatures, power use, and equipment statuses related to the performance of the geothermal ground loop and the hotel’s hot water system. Since only a limited DDC was planned, we installed a DAS dedicated to our purposes. A CR10X data logger scanned all channels every five seconds and continuously collected 5-minute data records. The data interval was chosen due to the variation of the loop flow rate. Each record was either averaged or totaled over the 5-minute period, depending on the data point. Data records were stored in the data logger’s memory for nightly retrieval. Table B2 displays the hardware comprising the DAS.
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. B-2 June, 2002
Table B3 lists each monitored point and type of sensor used.
Figure B1. Data Acquisition System Central Panel
Table B2. DAS Component Schedule
Component Manufacturer Description CR10X Campbell Scientific Data logger AM416 Campbell Scientific Analog Multiplexer (2) SDM-SW8A Campbell Scientific Switch Closure Module DC-112 Campbell Scientific Modem PS12LA Campbell Scientific 12 VDC Power Supply PS-200-1-A-1-N Mamac 24 VDC Power Supply
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. B-3 June, 2002
Table B3. List of Monitored Points and Sensors
Data Point Name Description Manufacturer Model Number
TAO Outdoor Air Temperature (moved to hot water return 1/98)
Mamac TE-211Z, 1000 ohm RTD
RHO Outdoor Air Relative Humidity Alta Labs HXD Series TB1 Bore Field Circuit 1 Return Temperature YSI Inc. YSI-030-55031, 0.1C Hermetic Thermistor TB2 Bore Field Circuit 2 Return Temperature YSI Inc. YSI-030-55031, 0.1C Hermetic Thermistor TB3 Bore Field Circuit 3 Return Temperature YSI Inc. YSI-030-55031, 0.1C Hermetic Thermistor TB4 Bore Field Circuit 4 Return Temperature YSI Inc. YSI-030-55031, 0.1C Hermetic Thermistor TB5 Bore Field Circuit 5 Return Temperature YSI Inc. YSI-030-55031, 0.1C Hermetic Thermistor TB6 Bore Field Circuit 6 Return Temperature YSI Inc. YSI-030-55031, 0.1C Hermetic Thermistor TB7 Bore Field Circuit 7 Return Temperature YSI Inc. YSI-030-55031, 0.1C Hermetic Thermistor TB8 Bore Field Circuit 8 Return Temperature YSI Inc. YSI-030-55031, 0.1C Hermetic Thermistor TB9 Bore Field Circuit 9 Return Temperature YSI Inc. YSI-030-55031, 0.1C Hermetic Thermistor TB10 Bore Field Circuit 10 Return Temperature YSI Inc. YSI-030-55031, 0.1C Hermetic Thermistor TPI1 Interior Pilling Circuit 1 Return Temperature YSI Inc. YSI-030-55031, 0.1C Hermetic Thermistor TPI2 Interior Pilling Circuit 2 Return Temperature YSI Inc. YSI-030-55031, 0.1C Hermetic Thermistor TPI3 Interior Pilling Circuit 3 Return Temperature YSI Inc. YSI-030-55031, 0.1C Hermetic Thermistor TPI4 Interior Pilling Circuit 4 Return Temperature YSI Inc. YSI-030-55031, 0.1C Hermetic Thermistor TPO1 Outer Pilling Circuit 1 Return Temperature YSI Inc. YSI-030-55031, 0.1C Hermetic Thermistor TPO2 Outer Pilling Circuit 2 Return Temperature YSI Inc. YSI-030-55031, 0.1C Hermetic Thermistor TPO3 Outer Pilling Circuit 3 Return Temperature YSI Inc. YSI-030-55031, 0.1C Hermetic Thermistor TPO4 Outer Pilling Circuit 4 Return Temperature YSI Inc. YSI-030-55031, 0.1C Hermetic Thermistor na Spare Pilling Circuit 1 Return Temperature YSI Inc. YSI-030-55031, 0.1C Hermetic Thermistor na Spare Pilling Circuit 2 Return Temperature YSI Inc. YSI-030-55031, 0.1C Hermetic Thermistor TGS Bulk Loop Temperature Returning From Ground YSI Inc. YSI-032-46041, 0.05C Hermetic Thermistor TPS Bulk Loop Temperature Returning From Pilings YSI Inc. YSI-032-46041, 0.05C Hermetic Thermistor TBS Bulk Loop Temperature Returning From Bore field YSI Inc. YSI-032-46041, 0.05C Hermetic Thermistor TGR Bulk Loop Temperature Entering Ground YSI Inc. YSI-032-46041, 0.05C Hermetic Thermistor THWE Entering Heat Pump Water Heater Temperature YSI Inc. YSI-032-46041, 0.05C Hermetic Thermistor THWL Leaving Heat Pump Water Heater Temperature YSI Inc. YSI-032-46041, 0.05C Hermetic Thermistor FLT Total Ground Loop Flow Onicon F-1200 Dual Turbine Flow Meter FLB Bore Field Flow Onicon F-1200 Dual Turbine Flow Meter FHW Hot Water Use Onicon F-1100 Single Turbine Flow Meter FHPWH Flow through Water Heating Heat Pumps Onicon F-1100 Single Turbine Flow Meter IP1 Loop Pump 1 Current Veris Series 921 Analog Output Current Sensor IP2 Loop Pump 2 Current Veris Series 921 Analog Output Current Sensor IP3 Loop Pump 3 Current Veris Series 921 Analog Output Current Sensor WB Total Building Energy Utility Pulse KYZ Contact on utility meter WLP Total Loop Pumping Energy Ohio Semitronics WL40R-071 w/ 3 sets of CTs WHPWH Hot Water Heat Pump Energy (hp 1-3) Ohio Semitronics WL40R-053 w/ 1 set of CT WPP Total Pool Space Conditioning Energy Ohio Semitronics WL40R-053 w/ 1 set of CT SWH1 Hot Water Heat Pump 1 Status Veris Series 900 Split Core Current Switch SWH2 Hot Water Heat Pump 2 Status Veris Series 900 Split Core Current Switch SWH3 Hot Water Heat Pump 3 Status Veris Series 900 Split Core Current Switch SWH4 Hot Water Heat Pump 4 Status Veris Series 900 Split Core Current Switch SPOOL1 Pool Dehumidification Unit Status Veris Series 900 Split Core Current Switch SPOOL2 Pool Space Conditioning Heat Pump Status Veris Series 900 Split Core Current Switch
Figure B2 through Figure B6 show connection diagrams for all the DAS equipment and sensors. Figure B7 displays a detailed connection diagram of the power transducer equipment used for the hot water heat pumps and pool heat pumps. Figure B8 displays the pump power transducer connection diagram with three sets of current transducers (CT’s) in parallel as used for the loop pumps.
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. B-4 June, 2002
CR10X DataloggerAnalog Terminal
SE 3
G
SE 4
G
SE 5
G
SE 2
SE 6
G
SE 7
G
SE 8
G
G
IP2 (+) 24VDC
121Ω
IP1 (+) 24VDC
121Ω
Black Red
Black Red
RHO (+) 24VDC
121Ω
Black Red Outdoor Air Relative HumidityGENERAL EASTERN RHT-2
SE 9
G
SE 10
G
SE 11
G
IP3 (+) 24VDC
121Ω
Black Red
Loop pump current and statusVERIS Hawkeye 921
TAO (+) 24VDC
121Ω
Black Red Outdoor Air TemperatureGENERAL EASTERN RHT-2
SE 12
G
AM416 COM L1
AM416 COM H2
AM416 COM L2
E1 AM416 COM H1
Figure B2. CR10X Analog Terminal Connection Diagram
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. B-5 June, 2002
SDM-SW8A#0
CR10X DataloggerControl Ports
Communications withdigital multiplexer
C1
C3
GND
C1
C2 C2
C3
GND
C4
C5
C6
C7
C8
Pulse 1
GND
24 VDC
FLT
Green
Black
Red
Pulse 2
GND
24 VDC
FLB
Green
Black
Red
Total Loop FlowONICON F-1200 dualturbine flow meter
Total Pilling FlowONICON F-1200 dualturbine flow meter
AM416 Clock
AM416 Reset
Figure B3. CR10X Digital Terminal Connection Diagram
L2
Black
RedH2
L1
H1Black
Red
Black
Red
(6)YSI-032-46041, 0.05C,Super stable thermistor(TGS, TGR, TPS, TBS,TDHWE, TDHWL) A
M41
6 T
erm
inal
s
L2
Black
RedH2
L1
H1Black
Red
Black
Red
(20) YSI-030-55031, 0.1Chermetically sealed thermistor(TPI1-4, TPO1-4, TPS1-2, TB1-10)
AM
416
Ter
min
als
Figure B4. AM416 Analog Multiplexer Sensor Connection Diagram
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. B-6 June, 2002
CR10XDatalogger
C3Communications withCR10X Datalogger
C1 IN
C1 OUT
C3
C2
SDM-SW8ATerminal
C2
C1
12 VDC
GND G
Campbell12 VoltPS12
Gnd
+12
JumperPositions
Address#0
InputConfiguration
8765
1234
20VDC@ 350 mA
SupplyCHG
CHG
654
123
654
123
IN 3
GND
5 V654
123
IN 4
GND
5 V654
123
IN 5
GND
5 V654
123
IN 6
GND
5 V654
123
IN 7
GND
5 V654
123
IN 8
GND
5 V654
123
VERIS Hawkeye 900self-powered current relay,
mount in breaker panel
+SPOOL2
-
Dessert Air PoolDehumidification HPRed / Black
VERIS Hawkeye 900self-powered current relay,mount in breaker panel
+SPOOL1
-
Pool Air HeatPumpsRed / Black
24 VDC
IN1
GND
FHW
Red
Green
Black
24 VDC
IN1
GND
FHPWH
Red
Green
Black
Figure B5. SDM-SW8A Switch Closure Module #0 Connection Diagram
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. B-7 June, 2002
SDM-SW8A #0
C3 Communications with CR10X Datalogger
C1 IN
C1 OUT
C3
C2
SDM-SW8A Terminal
C2
C1
12 VDC
GND G
Jumper Positions
Address #1
Input Configuration
8 7 6 5
1 2 3 4
IN 1
GND
5 V 6 5 4
1 2 3
VERIS Hawkeye 900
self-powered current relay, mount in breaker panel
+ SHW1
-
Hot Water Heat Pump #1
Red / Black
IN 2
GND
5 V 6 5 4
1 2 3
VERIS Hawkeye 900 self-powered current relay, mount in breaker panel
+ SHW2
-
Hot Water Heat Pump #2
Red / Black
IN 3
GND
5 V 6 5 4
1 2 3
VERIS Hawkeye 900 self-powered current relay, mount in breaker panel
+ SHW3
-
Hot Water Heat Pump #3 Red / Black
IN 4
GND
5 V 6 5 4
1 2 3
Utility Supplied Pulse 0.09 kWh/pulse
Red / Black
WB
IN 5
GND
5 V 6 5 4
1 2 3
Total Loop Pumping Energy OHIO SEMITRONICS WL40R-071 0.03 kWh/pulse
White / Black
WLP
IN 6
GND
5 V 6 5 4
1 2 3
Total Water Heating Heat Pump Energy OHIO SEMITRONICS WL40R-053 0.01 kWh/pulse
White / Black
WHPWH
IN 7
GND
5 V 6 5 4
1 2 3
Heat Pump Water Heater #4 Energy OHIO SEMITRONICS WL40R-053 0.01 kWh/pulse
White / Black
WHP4
IN 8
GND
5 V 6 5 4
1 2 3
12VDC
Figure B6. SDM-SW8A Switch Closure Module #1 Connection Diagram
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. B-8 June, 2002
White
1
2
4
3
5
6
9
10
12
11
13
14 CR10X Pulse Ch
CR10X Pulse Ch
fuse
fuse
LoadInput
L2
L3
H
Black
7
8
H
L1
White
fuse fuse
fuse
Figure B7. WL40R-053 Power Transducer Connection Diagram On a Single Circuit
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. B-9 June, 2002
White
1
2
4
3
5
6
9
10
12
11
13
14 CR10X Pulse Ch
CR10X Pulse Ch
fuse
fuse
Pump 3Input
L2
L3
H
Black
7
8
L1
White
fuse fuse
fuse
Pump 1Input
L2
L3
H
L1
Pump 2Input
L2
L3
H
L1
H
H
H
Figure B8. WL40R-071 Wiring Schematic to combine all loop pumps
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. C-1 June, 2002
APPENDIX C – CALIBRATION OF FLOWMETER
Background
Plumbing changes in the mechanical room of the Geneva Lakefront Hotel since 1997-98 resulted in sub-optimal flow conditions for the previously-installed Building Hot Water flowmeter (point FHW, Onicon F-1100). Ideally, the meter should be installed in a section of straight pipe with no elbows or fittings for at least 20 pipe diameters upstream and 10 pipe diameters downstream. Figure C1 shows the site of the meter, which is surrounded by fittings and elbows (as a result of recent plumbing changes). The meter was replaced with a new model at the beginning of this study, because the old meter had broken down.
Figure C1. Site of Building Hot Water Flowmeter
Clearly, readings from this meter could not be used until its output was checked for accuracy.
Procedure
A PolySonics Transit Time flowmeter was temporarily installed upstream from the Building Hot Water flowmeter. The Transit Time meter uses acoustic signals to remotely measure the flow through the pipe (no plumbing required). The Transit Time meter was left in place for 10 days, recording flow (gpm) data each minute. These data were then compared to the Onicon flowmeter for accuracy.
Flowmeter
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. C-2 June, 2002
Table C1. Settings for Transit Time Meter
Pipe Outer Diameter 4.125” Pipe Material Copper Pipe Lining None Type of Fluid Water Wall Thickness 0.110” Sensor Mounting “V” Configuration Sensor Spacing 2.292” Output (4-20 ma) 0-1000 gpm
Results Hot water use data from the two meters (hourly average) are shown in Figure C2. Readings from the two meters appear to correspond well to each other, although the Transit Time meter gives higher readings, with an average of 4.235 gpm for the period of April 23 – May 3, compared to 3.134 gpm for the Onicon meter.
23 24 25 26 27 28 29 30 1 2 3 4
April May
2002
0
5
10
15
20
25
30
Hot W
ate
r U
se (
gpm
)
Transit Time MeterOnicon Meter
Figure C2. Flow Readings From the Two Meters
The relationship between the readings from the two meters is shown in Figure C3 and Figure C4. Variability in the signals from the two instruments appear to be too high to give close agreement for the 5-minute data, probably because the timing of the loggers was off. However, hourly averages of the data show a close correspondence, with an R2 value of 0.946 for a second order polynomial curvefit. The second order polynomial equation shown in Figure C4 was thus employed as a transformation for the Onicon data, resulting in flow readings from the Onicon meter that are quite accurate.
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. C-3 June, 2002
Transit Time vs. Onicon Readings
0 20
Onicon (gpm)
0
5
10
15
20
25
30
Tra
nsi
t Tim
e (
gpm
)
Figure C3. Transit Time vs. Onicon Readings – 5 Minute Timestep
Transit Time vs. Onicon Readings
0 5 10 15 20 25
Onicon (gpm)
0
5
10
15
20
25
Tra
nsi
t Tim
e (
gpm
)
TT = 0.689+1.215 * Onic + -0.013 * Onic 2
Figure C4. Transit Time vs. Onicon Readings (Hourly Average)
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. D-1 June, 2002
APPENDIX D – SITE EXPERIENCES WITH PRESENT WS-HPWH SYSTEM The following pages contain the text of a letter prepared for the facility manager, which outlines our experiences and recommendations for the existing system.
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. D-2 June, 2002
Mike Dewaele Ramada Inn, Geneva Lakefront 41 Lakefront Drive Rtes. 5 & 20 Geneva, New York, 14456 Dear Mike, I’ve looked over the loading data that we’ve collected on your DHW system, and the following are my findings. The most significant complaint about the water heating system stemmed from the lack of water heating capacity that occurred during the winter months when the ground loop temperature was the coldest. The rated water heating capacity of the heat pumps are 20% less at the 40°F entering ground loop temperature observed in the winter than at 90°F entering ground loop temperature in the summer. This reduction in capacity causes slow recovery from the high DHW load that occurs during the morning, and low (105°F or less) DHW supply temperatures to the building. As we discussed, installing a natural gas fired heat source would alleviate the capacity and recovery problems. I believe the following is a description of the system you are considering:
• Replacing (or supplementing) all four HPWH units and 3,200 gallons of storage with a 900,000 BTUh boiler producing water at 130°F. Also replace the booster heater in the kitchen with a 150,000 BTUh instantaneous water heater producing water at 180°F (for the dishwasher).
Based on the measured data, we believe that removing the HPWHs would result in higher ground loop temperatures during the summer cooling season, resulting in lower system efficiencies and the possibility of space heat pumps locking out on high loop temperature – in fact this had occurred during the previous summer when the water heating heat pump had shut down because they had reached the system setpoint. Our recommendation is to pursue a gas-fired instantaneous water heater sized to meet the load required to maintain 125°F supply water temperature. This load was calculated from the monitored data using the measured hot water use and the supply temperature leaving the heat pumps. This load is equal to:
Load (hourBTU
) = 500 × DHW USE (GPM ) × ( 125°F – Recirc. Water Temp (°F))
CDH Energy Corp. P.O. Box 641 132 Albany Street Cazenovia, New York 13035
315-655-1063 FAX: 315-655-1058 [email protected]
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. D-3 June, 2002
Each morning, the high water draw caused by guest showers and laundry pulls down the supply water temperature leaving the HPWHs. The following plot displays the daily minimum hot water temperature and the corresponding hot water use (both on a 15-minute basis).
Minimum DHW Supply Temperature Variation with Water Use
0 20 40 60
Hot Water Use (gpm)
40
60
80
100
120
140
160
Tem
pera
ture
(F
)
Maximum Additional Load(31.8 F lif t, 41.8 gpm = 664.3 MBTUh)
Figure 1. Daily Minimum Hot Water Supply Temperature and Corresponding Water Use
The difference between the measured heat pump supply temperature and the desired supply temperature multiplied by the hot water use represents the load not met by the heat pumps. The highest 15-minute load not met was 664 MBTU/h, more than 1.5 times the capacity of the heat pumps. Load spikes of this magnitude were uncommon, as shown in Figure 2. This figure displays the distribution of the capacity deficit (or additional capacity required to maintain 125°F supply water temperatures). Typically only 200 MBTU/h of capacity would be required to meet the majority of this extra load, and installing as much as 300 MBTU/h of capacity would meet the water heating loads for all but 2 hours of the year.
125°F Desired Supply Temperature
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. D-4 June, 2002
0 200 400 600 800
Required Additional Capacity to Meet 125 F Supply Water Temp. (MBTUh)
0
200
400
Num
ber
of H
ours
Additional Unit Percent of Hours w/
Capacity (MBTUh) Additional Load Met
0 MBTUh 0.0%
100 MBTUh 89.6%
200 MBTUh 97.7%
300 MBTUh 99.4%
400 MBTUh 99.8%
500 MBTUh 99.9%
600 MBTUh 99.9%
700 MBTUh 100.0%
Figure 2. Capacity Deficit Distribution Histogram
An example of an instantaneous water heater that will meet this extra load is the Raytherm – Model NH-514, manufactured by Raypak, Inc. (www.raypak.com). This unit provides 420 MBTUh of heating capacity with up to 8 stages of capacity control. To minimize pressure drops in the piping system, it may be desirable to install the unit in a parallel flow arrangement with the supply water piping as shown:
Instantaneous WaterHeater
Shut OffValve
Shut OffValve
Existing 4" DHW SupplyPiping
To HotelFromTanks
New 2" PipingFor IWH
T1
T2
Figure 3. Simplified Piping Diagram
This piping arrangement will allow continuous flow through the water heater, and simple controls can be established to operate the unit when the temperature at aquastat T1 falls to a certain level (possibly a 5°F deadband). Also it may be desirable to control the unit capacity to maintain a
HPWH Analysis Project Geneva Lakefront Hotel
CDH Energy Corp. D-5 June, 2002
maximum outlet temperature at aquastat T2 (possibly 130-135°). Many instantaneous water heaters offer multiple-stages or continuous modulation of burner capacity to meet this need. The quote supplied to the hotel for the installation of a 900 MBTU/h boiler and 150 MBTU/h instantaneous water heater was $40,000. It was not detailed what fraction of the total cost was for the boiler installation and what fraction was for the kitchen water heater, but standard costing guides (such as RS Means) indicate that the 900 MBTU/h boiler system will be on the order of $25,000 (installed as a retrofit). The 420 MBTU/h instantaneous water heater is estimated to cost $10,000-$15,000 (installed as a retrofit), requires significantly less labor to install, and requires no additional storage tanks. The total additional load to be met by the gas water heater is estimated at 215 MMBTU/year (using data collected during March 1998 – December 1998 and Spring 2002). Total gas input and cost to meet this load (assuming 82% efficient equipment) is 2,621 therms/year with a cost of $1,310/year (assuming $0.50/therm average annual cost). Your price for gas is slightly lower than this now, but $0.50/therm is a reasonable price point given the volatility of the gas prices recently. We agree that the hotel should pursue the gas fired kitchen water heater to replace the electric instantaneous water heater supplying the dishwasher. I hope this helps in your decisions about your future modifications to the hotel’s DHW system. Please call with any questions. Sincerely,
Adam C Walburger Project Engineer