rcx 06 office building final report peci

8/6/2019 RCx 06 Office Building Final Report PECI

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Retrocommissioning ReportBuilding X

City Y, California

Prepared with funding from

Utility

By

Portland Energy Conservation, Inc.1400 SW 5th Avenue, Suite 700Portland, OR 97201

In partnership with IMPORTANT NOTICE: This sample document isprovided for instructional purposes only. CCC is notrendering advice concerning any commission project orpractices. This document is neither approved nor intendedto serve as a standard form. The user of these documentsshould confer with qualified advisors with respect to itscommissioning and other documentation.

Partner

Final ReportMarch 2002


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TABLE OF CONTENTS

EXECUTIVESUMMARY................................................................................................ 1

Overview of Results...................................................................................................... 1Measure Prioritization and Tracking ............................................................................... 2

Recommendations, Cost and Savings Summary Tables ................................................... 2Findings And Implementation Plan Summary Table ........................................................ 4

INTRODUCTION.......................................................................................................... 5

METHODOLOGY........................................................................................................... 5

Investigation & Data Collection ..................................................................................... 5Analysis of Data ........................................................................................................... 8Implementation of Recommendations.......................................................................... 12Verification of Energy Savings ..................................................................................... 12

BASELINE FACILITY DESCRIPTION......................................................................... 13

General Information ................................................................................................... 13Hvac Systems ............................................................................................................ 13Electrical Systems....................................................................................................... 15Operations & Maintenance Procedures......................................................................... 16Energy Utilization ....................................................................................................... 16End-Use Breakdown ................................................................................................... 17

FINDINGS,RECOMMENDATIONS& IMPLEMENTATION......................................... 18

Detailed Findings........................................................................................................ 18

IMPLEMENTATION OF RECOMMENDATIONS.......................................................... 37

Implementation Plan .................................................................................................. 37MEASUREMENT &VERIFICATION OF SAVINGS...................................................... 38

Measurement & Verification Plan................................................................................. 38Measurement & Verification Results............................................................................. 39

MAINTENANCE OF SAVINGS.................................................................................... 43

Implementation Persistence ........................................................................................ 43Benchmarking & Continuous Monitoring of Energy Use ................................................. 43Energy Reduction Targeting........................................................................................ 43Recommissioning ....................................................................................................... 43

APPENDICES............................................................................................................. 44

Appendix A. Photos ................................................................................................... 45Appendix B. Utility History Analysis Figures................................................................. 49Appendix C. Pre-retrofit Data Logging Trend Analysis Figures ...................................... 50Appendix D. Pre-retrofit Monitored Average Daily Load Shapes .................................... 57Appendix E. Post-retrofit Data Logging Trend Analysis Figures..................................... 62Appendix F. Retrocommissioning Plan......................................................................... 63Appendix G. Savings and Cost Estimates..................................................................... 69

Portland Energy Conservation, Inc. (PECI) Page i


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Building X City Y, CA

Retrocommissioning ReportBuilding X

City Y, California

EXECUTIVE SUMM ARY

OVERVIEW OF RESULTS

Portland Energy Conservation Incorporated (PECI) in conjunction with Partner and Utility) performed aretrocommissioning evaluation on the 125,000 SF Building X office facility in City Y, California. Theretrocommissioning process involved a coordinated effort between PECI, Partner, and the buildingoperating staff. Documents were provided for review, interviews and field investigations were conducted,building systems were monitored and analyzed, energy conservation measures were implemented by theowner, and these measures were monitored to verify savings. This report presents the results of theseefforts.

Retrocommissioning, or existing building commissioning, is an event in the life of a building that applies asystematic investigation process for improving and optimizing a buildings operation and maintenance. It istypically an independent process that focuses on the buildings energy using equipment such as the HVACand other mechanical equipment, lighting equipment, and related controls. It may or may not emphasizebringing the building back to its original intended design specifications. In fact, via the process, theretrocommissioning team may find that the original specifications no longer apply. The process may resultin recommendations for capital improvements, but its primary focus is to optimize the building systems viatune-up activities, improved operation and maintenance (O&M), and diagnostic testing. Details of the

process used in this project are provided later in the report.

The retrocommissioning process involved obtaining documentation about the facility equipment and itsoperation as well as making a site visit for further review of operating parameters and conditions with themaintenance staff. Selected systems were monitored with data loggers for a two-week period to trendsystem operation. Eight findings with associated energy savings were identified at the facility and fourfindings were recommended by PECI for implementation. Energy savings estimates were made for thesignificant findings where sufficient data was available and project scope allowed. An additional fivemeasures were identified but not formally presented because the payback was too long, there wasinsufficient information, or the measure was not energy related.

PECI then met with the Building X management staff to discuss and review all of the findings, and themanagement decided to implement three of the measures. PECI offered limited assistance duringimplementation, but Building X took full responsibility for contracting out the implementation orperforming the work themselves. The measures and findings selected by Building X for implementation aresummarized below.

Portland Energy Conservation, Inc. (PECI) Page 1 2005, Portland Energy Conservation, Inc. (PECI). All rights reserved.


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B

Portland 2005,

uilding X City Y, CA

Energy Conservation, Inc. (PECI) Page 2Portland Energy Conservation, Inc. (PECI). All rights reserved.

RECOMMENDATIONS,COST AND SAVINGS SUMMARYTABLES

Each measure was originally prioritized by PECI on a scale of 1 to 3 to assists the owner in determining theorder in which to implement the findings. A ranking of 1 represents a high priority finding, 2 representsa medium priority finding, and 3 represents a low priority finding. The ranking is subjective, but based on

an overall evaluation with consideration given to the criteria of energy savings, project cost, likelihood ofbeing implemented, indoor air quality, safety, and comfort. The table was also used to track measureimplementation. Refer to the following Finding and Implementation Plan Summary table for details.

M EASURE PRIORITIZATION AND TRACKING

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Other Measures Considered. Five measures were identified but not formally presentedbecause the payback was too long, there was insufficient information, or the measure wasnot energy related.

Total Project Summary. The combined measures implemented by the owner result intotal annual savings of 237,937 kWh and a utility cost savings of $20,062, whichcorrespond to a 9.9% reduction in annual energy usage and 4.7% reduction in annualutility costs. The calculated savings have been reduced by 5% to account for minorinteractive effects between measures that reduce the savings from one measure whenanother is implemented. The total cost to implement all of the measures was $14,393,resulting in an overall simple payback of 0.7 years. Refer to the following SavingsSummary Projection table and Energy Usage and Cost Index Comparison Projection

graph for details of the total project savings and costs.

Capital Improvement Measures. One combined O&M/Capital Improvement measurewas implemented to bring the building back to its original design intent. The totalestimated annual savings for this measure is 29,450 kWh and $3,800 in annual utilitycosts. Estimates of energy savings have been reduced by 5% to account for minor

interactive effects between measures that reduce the savings from one measure whenanother is implemented. The total cost to implement this measure was $14,150 based oncontractor invoice. This results in a simple payback of 3.7 years.

Operation and Maintenance Measures. Four operation and maintenance (O&M)measures were identified but only two measures were selected by the owner forimplementation. However, since energy savings for one of these O&M measures directlyimpacts the savings associated with the selected capital improvement measure, overall

energy savings for the combined O&M/Capital Improvement measure is presented in thesection below. Therefore, the total estimated annual savings for the O&M measureimplemented by the owner are 208,487 kWh and $16,262 in annual utility costs.Estimates of energy savings have been reduced by 5% to account for minor interactiveeffects between measures that reduce the savings from one measure when another isimplemented. The total cost to implement this measure was $243 based on contractorinvoice. This results in approximately a month payback.

Building X


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Portland Energy Conservation, Inc. (PECI) 2005, Portland Energy Conservation, Inc. (PECI). All rights reserved.

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Building X


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Building

Portland Energy Conservation, Inc 2005, Por

X City Y, CA

. (PECI)tland Energy Conservation, Inc. (PECI). All rights reserved.

ID Finding Recommendation Name1

Packa e2

Prio

01 CSI scheduling and control sequences need to be optomized Scheduling and Programming Improvements 1

02 Supply fans cycle on and off during unoccupied hours Rewire Heat Pump Supply Fans 1

03 Single speed fans short cycle to meet cooling load Install Variable Frequency Drives on Fluid Cooler Fans* 2

04 Single speed fans short cycle to meet cooling load Install Two-speed Motors on Fluid Cooler Fans* 2

05 Water loop temperature and fan control should be optimized Reduce Condenser Water Loop Temperature* 1

06 Water loop temperature and fan control should be optimized Reduce Condenser Water Loop Temperature and Install Two-speed Motors* 2

07 Water loop temperature should be optimized Reduce Condenser Water Loop Temperature and Install VFDs* 2

08 West loop pump is circulating too much water Trim West Loop Pump Impellers 1

09 Heat pump have never been tuned-up Tune-up Heat Pumps 3

10 East loop pump may be circulating too much water Modify East Loop Pump Flow Rate 3

11 Fluid cooler chemical feed system may be malfunctioning Inspect Fluid Cooler Chemical Treatment 3

12 Convert water loops to variable volume systems Install Automatic Two-way Control Valves on each Heat Pump 3

13 Make-up water flow is unrestricted Close Water Loop Make-up Line Valve 3

1. Recommendations with an (*) in the title are mutually exclusive with other measures

2. Package identification: 1 - low cost measure, 2 - capital improvement measure, 3 - other measure considered, 4 - non-energy saving measure

3. Priority ratings: 1 - high priority, 2 - Medium priority, 3 - low priority

4. Both two-speed motors and condenser water reset measures were implemented. Measure 06 evaluated the interaction between the two measures.

5. Facility personnel were aware of the situation and fixed the problem

FINDING AND IMPLEMENTATION PLAN SUMMARY

Notes:

FINDINGSAND IMPLEMENTATION PLAN SUMMARYTABLE


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INTRODUCTION

This report presents the final results of the retrocommissioning study performed on Building X, an officefacility located in City Y, California. This retrocommissioning study was completed as part of a

retrocommissioning program funded by Utility. Portland Energy Conservation Inc. (PECI) and Partnercompleted the retrocommissioning study.

Retrocommissioning is an excellent way to obtain energy savings through low cost improvements thatoptimize building systems so that they operate efficiently and effectively. On average around the country,commissioning existing buildings reduces a buildings energy costs by 5% to 20%. The payback forinvestment in low cost opportunities typically ranges from a few months to two years. In addition,retrocommissioning can improve occupant comfort, reduce indoor air quality problems and reduceoperations and maintenance costs.

The retrocommissioning process also identifies potential capital intensive improvements that can be made at

the facility to further reduce energy usage and utility costs. Often, the savings associated with the low costimprovements can be used to buy down the implementation costs associated with the capital-intensivemeasures and make the overall package more economically viable.

METHODOLOGY

Commissioning of existing buildings, or retrocommissioning is a systematic process applied to existingbuildings to identify and implement operational and maintenance (O&M) improvements and to ensurebuilding system functionality. The primary goal of retrocommissioning is to optimize equipment andsystem operation so that they function together efficiently and effectively, although retrocommissioning

may also result in recommended capital improvements. The basic process includes four fundamentalprocedures:

Investigation and data collection

Analysis of data

Implementation of recommendations

Verification of energy savings

Each of these procedures is discussed in detail below.

INVESTIGATION &DATACOLLECTION

The retrocommissioning process begins by collecting and evaluating data pertaining to facility equipmentand current operation. The primary tasks for this project are outlined below.



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Documentation Review

The investigative process consists of first obtaining as much building documentation as possible to allowPECI and Partner staff to become familiar with the building and its systems. Equipment lists, controlprogram code, system schematic drawings and 12 months of utility billing data are generally requested. For

the current project, the billing history and partial mechanical plans were available for review prior to the sitevisit.

Initial Site Assessment

The next step was to conduct an initial site assessment. The initial site assessment consisted of spendingtwo days in the building during November 2001 interviewing staff, reviewing control sequences andequipment operating schedules programmed into the central building automation system (BAS), inspectingand testing equipment, and performing an analysis of the site-gathered data. The assessment identifiedseveral significant findings, as well as pin pointing areas for monitoring and testing.

Manual TestingPECI executed manual test procedures during the site visit to determine system operation for examplemanipulating thermostat settings during unoccupied periods. It was noticed during the site visit that one ofthe heat pump supply fans continued to operate even when the BAS control schedule commanded the unit tobe off. This indicates that the heat pump may be wired incorrectly and will not achieve the desired controlduring unoccupied hours. In order to verify the pervasiveness of this control problem, the monitoring planincluded trending the heat pump compressor and supply fan independently on several units.

Short-term Diagnostic Testing Through Monitoring/Data Logging

Short-term diagnostic testing utilizes the application of specialized software and hardware tools to gather

and analyze data for the evaluation of the performance of building energy systems. Short-term diagnostictesting results were applied to system retrocommissioning, the calibration of building simulation models,

and system tune-ups. PartnersENFORMA Portable Diagnostic Solutions is a set of tools used to organizeand standardize the diagnostic testing process.

The first step in the application of short-term diagnostic testing was the development of a monitoring plan.The plan contains goals, objectives, analysis techniques, and instrumentation requirements. The monitoringplan for this building was developed with information gleaned from the building operators and existingdocumentation such as operation and maintenance manuals, as-built plans, and sequences of operation. Theoriginal building walk-through performed in early November 2001 served to initially identify operation andmaintenance opportunities and decide which equipment and systems will be monitored in order to ascertain

actual system operation and detect additional opportunities.

The buildings heating and cooling needs are served by approximately 175 water source heat pumps and theheat pumps are separated into east and west circulation loops. Each loop consists of an evaporative fluidcooler, a natural gas-fired hot water boiler, and two main loop pumps operating in a lead/lag configuration(i.e. only one pump per loop operates at a time).



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Based on utility data and building operator information, it was verified that the heating load on the buildingnever required the boilers to operate. Therefore the boilers were not monitored. The following central plantequipment and data points were monitored:

Amperage for the east loop pump and west loop pump

Amperage for the fan and spray pump on each loops evaporative fluid cooler

East and west loop supply and return water temperatures

Ambient air temperature

There are approximately 25 heat pumps per floor. A selection of heat pumps was chosen from the 3rd, 5th,and 6th floors for monitoring. Total heat pump amperage (supply fan and compressor) was measured at thehigh voltage breaker panels, allowing multiple units to be easily monitored. This technique allowedoperating data to be collected on approximately 35% of the buildings units. In addition, four heat pumps(one on each of the 1st, 3rd, 4th, 7th floors) were monitored in detail to provide insight into unitperformance and zone load requirements. The following points were measured for each of these units: (1)

supply air temperature; (2) return air temperature; (3) compressor amperage and (4) supply fan amperage.

All of the pre-retrofit monitored data was used to establish existing equipment operating loads andschedules, estimating existing energy consumption, and providing insight into how each piece of equipmentinteracts with each other and with respect to environmental conditions.

Data was collected using Partners MicroDataLogger, a battery powered, four-channel data logger thatrecords time-series data using a variety of interchangeable sensors and transducers. The collection periodconsisted of two weeks, beginning at midnight on November 16th, 2001, and ending at midnight onNovember 29th, 2001.

Spot measurements of amperage, voltage, power, and power factor were collected for each piece ofequipment and each panel circuit monitored. These spot measurements are used to convert monitoredcurrent data (A) into power data (kW) during the analysis process, as well as calibrate the amperage valuesmeasured by the current transformers.

TheENFORMA system was used to create an instrumentation plan and to initialize the data loggers. Table1 lists the pre-retrofit monitored data points.



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Table 1 Monitored Points List

System Component Monitored PointUnit of

MeasurementUnit

Conversion

Ambient temperature oF -

East Water Loop supply temperature oF -

return temperature oF -

West Water Loop supply temperature oF -


East Water Loop Pump current amps kW

West Water Loop Pump current amps kW

East Cooling Tower Fan current amps kW

West Cooling Tower Fan current amps kW

East Cooling Tower Spray Pump current amps kW

West Cooling Tower Spray Pump current amps kW

Heat Pumps (4 units) supply temperatureoF -


fan current amps kW

compressor current amps kW

Heat Pumps (at panels, ~34 units) current amps kW

Data was collected every three minutes. At the end of the monitoring period, the data loggers were removed

and the data was downloaded and analyzed using theENFORMA software's suite of graphical visualizationtools and conditional filters. These tools allow the analysis of large quantities of data, providing load shapesand diagnostic plots for quick identification of system operation and problems. Trend analysis was used tovalidate existing energy usage and identify potential conservation opportunities as well as to develop thebaseline building model. All of the pre-retrofit trend graphs are presented in Appendix C and the averagedaily load shapes for various systems and equipment are presented in Appendix D.

ANALYSIS OF DATA

PECI and Partner analyzed the site interview data, written documentation, trend and monitored data andmanual test data. From this work the findings were formalized, estimates for their associated energy savings

and costs to implement were developed, and the results were presented to the owner.

Baseline Building Calibration

The energy baseline for this building was established through the use of the DOE-2.1E building energyanalysis simulation developed at Lawrence Berkeley National Laboratory and Los Alamos National



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Laboratory. It is the most accurate and well-documented energy-modeling program currently available inthe United States.

DOE-2.1E calculates hour-by-hour building energy consumption over an entire year (8,760 hours) using

hourly climate data for the location under consideration. Input to DOE-2.1E consists of a detaileddescription of the building being analyzed including hourly scheduling of occupants, lighting, equipment,and thermostat settings. DOE-2.1E provides accurate simulation of such building features as shading,fenestration, interior building mass, envelope building mass, and the dynamic response of differing heatingand air conditioning system types and control strategies. DOE-2.1E also contains a dynamic daylightingmodel to assess the influence of daylighting on thermal and electric lighting demands.

The DOE-2.1E simulation process begins by developing a baseline model of the building based on buildingplans and specifications as well as through discussions with the building operators, occupants, andmaintenance personnel. Once the set points, load shapes, and schedules are input, the model is then runwith climate data corresponding to this geographic location (City Y, CA).

At this point, the model results are compared to the actual monthly energy usage obtained from energy bills.Correlation of electrical consumption and demand are determined. Typically, if there are discrepancieslarger than 10% for any month, further tuning of the model is performed. Plots of the monthly electricalconsumption and demand predicted by the baseline model verses the actual billing data are presented inFigure 1 and Figure 2, respectively.

Building XMonthly Electric Consumption

Figure 1 - Monthly Electrical Energy Consumption, Baseline Model verses Billing Data



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Building XMonthly Electric Demand

Figure 2 - Monthly Electrical Demand, Baseline Model verses Billing Data

As we can see from the preceding graphs, the DOE-2 model reasonably tracks the actual energy and demandusage profiles for the building. Since DOE-2 uses historic weather data in its calculations, minor

differences between the model and actual consumption can most likely be attributed to local weatheranomalies occurring during the billing period.

Once the DOE-2 baseline model is calibrated, parametric analyses are performed by making changes to themodel corresponding to energy conservation measures identified during the building walk-through audit andfrom analysis of the monitored data. These parametric analyses result in predicted utility consumptionsavings, and are ultimately used to evaluate the best combination of energy conservation alternativesthrough further economic analysis of the individual and combined ECMs.

Energy Use Analysis

The calibrated DOE-2 baseline building model was also used to determine the breakdown of existing energy

usage for various pieces of equipment in the facility (end-use profile) and the overall energy usage persquare foot (energy use index). The end-use profile allows the user to see where all of the energy is beingused in the facility and where the greatest opportunities for energy conservation exist. The energy use indexcan be used to compare energy usage in the existing facility against similar building types under similarweather conditions. For example, multiple office facilities in similar climates can be compared to eachother and the ones with the highest energy use per square foot may have greater opportunities for energy



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conservation. Refer to theBaseline Facility Description section for detailed discussion of existing energyusage at the facility.

Energy Savings Calculations

Energy savings can be calculated in a variety of ways. For simple measures, customized spreadsheets basedon standard engineering practices and rules of thumb can be used to estimate savings. For the evaluation ofmore complex systems and to account for equipment interactions, a simulation program calculating energyusage on an hourly basis was used. For this project, both spreadsheets and DOE2.1E were used to estimateenergy savings. The calibrated building model was used to establish baseline energy consumption andinformation gathered during the site visit was used to validate the energy savings calculations.

Cost savings are generally calculated using the average unit cost per utility. For example, the average costof electricity is calculated by dividing the total monthly cost, which includes demand costs and taxes, by themonthly consumption. However, some measures may not achieve any demand savings or may only effectoff-peak demand usage, therefore these measures cannot use the average electricity cost described above to

estimate cost savings. In addition, the energy commodity charge fluctuates from month to month and variesbased on time of use. The DOE-2 simulation model used the extensive time-of-use rate structure to estimatecost savings, however spreadsheet calculations utilized either an average cost $0.078/kWh when no demandsavings are available, or $0.1211/kWh when demand savings could be claimed. Electricity commoditycharges in California have lowered significantly over the past 6 months and appear to have stabilized.Therefore the average energy costs (both with and without demand costs) are based on the average for thepast 5 months, rather than including the extremely high rates from last summer. All costs includeappropriate taxes.

Project Costs

Preliminary implementation costs are estimated for each measure based on a variety of methods i.e.contractor budgetary cost estimates, R.S. Means cost estimation guidebooks, manufacturer price lists, etc.The cost projections assume that facility staff will complete the installation or be available to assist acontractor with the implementation. Costs include materials, labor and taxes, as well as contractorsindustry-standard overhead and profit mark-up, engineering design and construction-phase service fees,contingencies, and project management fees, if applicable. However, measurement and verification (M&V)costs, performance bond costs, and audit report costs have not been included, nor have costs associated withdevelopment of design documents and specifications that may be required to successfully engineer andimplement some capital-intensive projects.

Measure Selection

Energy and cost savings and implementation costs were first determined for each measure on an individualbasis. Some measures are calculated using spreadsheets while others were calculated using the DOE-2simulation program. Energy savings for individual measures calculated using DOE-2 were also run togetheras a package to account for the interaction between the measures. All measures are then entered into asummary spreadsheet and prioritized based on payback. PECI then recommends specific measures forinstallation at the facility and the spreadsheet totals energy savings, cost savings, and implementation costfor only these measures. The total energy and cost savings for these measures are then de-rated by a factor



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of 5% to account for minor interactive effects between measures that reduce the savings from one measurewhen another is implemented. There are various reasons for not recommending a measure. For example, insome cases, measures are mutually exclusive with others and a selection must be made. Spreadsheets andmodel simulation information for all measures with energy saving calculations can be found in Appendix G

Savings and Cost Estimates.

IMPLEMENTATION OF RECOMMENDATIONS

PECI presented an interim report to the owner describing all of the findings identified for the facility andwhich measures PECI recommended for implementation. The owner reviewed the report with PECI andselected which measures were to be implemented. The owner performed as much work as possible using inhouse staff and hired outside contractors to complete the work when necessary. Implementation cost foreach measure in the final report has been revised using actual installation costs based on contractor invoices.

VERIFICATION OF ENERGYSAVINGS

The measurement and verification techniques used follow the IPMVP (International PerformanceMeasurement and Verification Protocol) Option D Calibrated Simulation. Following the implementationof the recommended measures, a sampling of the systems were re-monitored to ensure that themodifications were made and are performing as intended. In some cases, measures did not lend themselvesto M&V using the calibrated model approach. For these measures Option A Partially Measured RetrofitIsolation was used, which employs engineering calculations verified with site inspections and short termmonitoring.

The equipment selected for post-monitoring were based on the measures that were implemented. A list ofthese monitored points is presented in Table 2. Energy savings were based on the difference between thepre-and post-installation data and load shapes. This data was used to develop the post-installation building

model or average daily load shapes, which were then compared to the original baseline model and loadshapes to re-calculate the energy savings where necessary. Energy and utility cost savings for each measurein the final report have been revised, if necessary, to reflect post-retrofit monitored data.

Table 2 Monitored Points List for Measurement & Verification Phase

System Component Monitored Point

Unit of

Measurement

Unit

Conversion

Heat Pumps (at panel L5B) current amps kW

East Water Loop supply temperature oF -

East Water Loop Pump current amps kW

East Spray Pump current amps kW

East Cooling Tower Fan current amps kW



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BASELINE FACILITY DESCRIPTION

GENERAL INFORMATION

Building X office building is a 125,000 square foot, seven-story facility. The building was constructed in1983, and is made up of 85 different tenants, with 50 stand-alone and 35 executive office suites, and a smalldeli on the 4th floor. The walls are primarily curtain walls with R-11 insulation, and the roof is concrete.The windows are single-pane glass with reflective properties and non-operable aluminum frames.

General occupancy for the building is 7 AM to 5 PM Monday through Friday and partial occupancy onSaturdays from 8 AM to 12 PM. Typical daily occupancy is approximately 500 people, which includes asteady and transient populace. Building occupancy is estimated to be 20% on Saturdays. Tenant occupancyhas been approximately 100% for the last few years.

HVAC SYSTEMS

The facility is served by a water-source heat pump system. A water-source heat pump system generallyconsists of individual heat pumps, central water loop circulation pumps, fluid coolers, and boilers. Thegeneral concept behind a water-source heat pump system is that each individual unit can provide heating orcooling as needed by the space by absorbing or rejecting heat, respectively through the circulation waterloop. This system allows energy to be transferred from one part of a building to another if necessary. Forexample under certain weather conditions, the north end of a building may require heating while the southend may have a net cooling load. The heat rejected to the water loop by the units in cooling mode can beabsorbed by the units in heating mode to satisfy space requirements. A fluid cooler is generally used todissipate excess heat from the loop and a hot-water boiler is generally used to add heat to the loop ifnecessary. The water-source heat pump system for Building X is separated into two independent waterloops: one serving the east side of the building; and one for the west side of the building. Each water loop

system consists of individual heat pumps, two circulation pumps operating in a lead/lag configuration, anevaporative fluid cooler, and a natural gas-fired hot water boiler. Each component of the system isdescribed in detail below.

Individual Heat Pumps

There are several different sizes of heat pumps installed throughout the building depending on space heatingand cooling needs. Specification for each heat pump type is outlined in Table 3.



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Table 3 Heat Pump Specifications

Description HP-1 HP-2 HP-3 HP-4 HP-5

Quantity 14 7 21 119 14

Fan Power (HP) 1/20 1/6 1/6 1/6 1/3

Air Flow (CFM) 285 520 605 900 1,475Cooling Mode

MBH 9.4 14.0 18.0 24.0 40.0

EER 8.3 7.6 8.3 8.4 9.2

Heating ModeMBH 10.6 19.3 22.9 30.7 46.9

EER 7.8 8.9 8.9 9.9 9.6

Water Flow (GPM) 2.3 3.5 4.5 6.0 10.0

Outside ventilation air is ducted to each heat pump from a common supply duct located on each floor. Thesupply ducts serving each floor are connected to a chase extending from the roof to the ground floor, with

the outside air intake louver located on the roof.

Water Loop Circulation Pumps

There are two independent water loops serving the building and each loop consists of two pumps in a lead /lag configuration (only one pump per loop operates at a time). The west loop water pump was designed for600 GPM at 84 feet of head, with a 20 HP motor. The east loop was designed for 450 GPM at 90 feet ofhead, with a 15 HP motor.

Evaporative Fluid Coolers

There are two independent evaporative fluid coolers serving the east and west water loops and each fluid

cooler consists of a single-speed 25 HP fan motor and a 2 HP spray pump. The west loop fluid cooler israted at 200 tons and 600 GPM water flow rate. The east loop fluid cooler is rated at 160 tons and 445 GPMwater flow rate. Both fluid coolers have been recently replaced.

Boilers

There are two independent natural gas-fired hot water boilers serving the east and west water loops and eachunit is rated at 945 MBH and 80% efficiency. Due to the nature of the thermal characteristics of thebuilding, neither boiler has ever operated but they are available should supplemental heat be required.

HVAC Controls

The facility is controlled by a CSI energy management and control system (EMCS). The CSI systemcontrols the buildings water loop heat pump system and exterior lighting in the following manner:

Scheduling operation of the heat pumps

Maintaining water loop temperature (which in turn controls the operation of the fluid cooler fansand spray pumps).



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Controlling operation of the water loop circulation pumps through heat pump schedules Scheduling of selected exterior lighting

The general operating schedule for the heat pumps are 6 AM to 6 PM Monday through Friday, with

approximately 50% of the units scheduled from 8 AM to 12 PM on Saturdays. Note the buildingoccupancy and equipment operating schedule is longer on both weekdays and weekends during March andApril because several tenants are accountants and this is tax season.

Water loop temperature is maintained at approximately 85F and the water loop circulation pumps arecommanded off when the heat pumps are disabled. Selected exterior lighting is scheduled to turn off atmidnight. Each individual heat pump is controlled by a thermostat located within the zone served. Heatingand cooling setpoints are 65F and between 70F and 72F, respectively. Most supply fans are in the autoposition, which turns the fan on when the compressor is on and off when the compressor is off.

However, information gathered during the site visit and through short-term equipment monitoring indicates

that many building system are not being controlled as intended. For example several heat pumps operateduring unoccupied hours, the water loop pumps are operating continuously, and heat pump supply fanscontinue to cycle on and off during unoccupied hours even when the units are disabled.

ELECTRICAL SYSTEMS

Interior Lighting

The interior lighting for the facility was retrofitted in 1991 to 2-lamp and 4-lamp four-foot T-8 fluorescentfixtures with electronic ballasts as well as 2-lamp, 18-watt compact fluorescent fixtures. Lighting load isestimated at 1.06 watts per square foot.

Exterior Lighting

The building has two levels of covered parking under the building itself and is lit by high-pressure sodiumfixtures. The sides of the parking structure are open but the lights remain on 24 hours per day, 7 days perweek for security. High-pressure sodium fixtures also light surface parking and building perimeter areas,but these fixtures are controlled by a photocell in conjunction with the CSI energy management system.The total exterior lighting load is estimated at 7 kW.

Lighting Controls

All interior lights are controlled by toggle switches. The surface parking and perimeter areas are controlledby a photocell in conjunction with the CSI energy management system. It is estimated 15% of the interiorlighting is on 24 hours per day for security.

Miscellaneous Electrical Systems

There is a small deli located on the 4th floor. Miscellaneous electrical equipment at the facility includescooking equipment (for example microwave oven, crock pots, coffee brewers), kitchen refrigeration units,5-gallon electric water heaters in the bathrooms, and general office plug loads. Average connect load is



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estimated at 175W per employee during occupied hours based on observations of equipment made duringthe on-site visit. This plug load density accounts for all office equipment, kitchen refrigeration units, coffeemakers, and task lights. Approximately 50% of the office plug loads are turned off during unoccupiedhours.

OPERATIONS &MAINTENANCE PROCEDURES

Currently, in-house personnel perform most equipment operation and maintenance. This includes adjustingthermostats, replacing light bulbs, replacing filters in the heat pumps, and general repairs. Outsidecontractors are used if facility staff is unable to remedy the situation or to perform more complexmaintenance procedures.

ENERGYUTILIZATION

Building X uses primarily electricity to meet its energy needs. Even though there are two natural gas-firedhot water boilers serving each water loop, these units have yet to be used. However, the facility is charged amonthly basic meter fee. The facility used 2,394,824 kWh of electricity at a cost of $427,608 per year(including demand charges and taxes) for the 12-month period between October 2000 and September 2001.This corresponds to an energy use index (EUI) of 65.39 kBTU/sq. ft./year and an energy cost index of$3.42/sq. ft./year. Energy consumption and utilization for the facility is summarized in Table 4.

Table 4 Building X Utility History and Energy Utilization

Date

Electrical

Energy

Usage

(KWH)

On-peak

Demand

(KW)

Non-

coincident

Demand

(KW)

Total Electricity

Cost - including

demand and

taxes ($)

Nominal

Electrical

Rate

($/KWH)

ECI

($/Sq. Ft.)

EUI

(kBTU/Sq.Ft.)

Oct-00 203,890 529 627 $34,864 $0.17099 $0.279 5.57

Nov-00 197,428 427 583 $34,899 $0.17677 $0.279 5.39

Dec-00 207,608 424 589 $62,355 $0.30035 $0.499 5.67

Jan-01 186,694 436 575 $44,295 $0.23726 $0.354 5.10

Feb-01 183,104 450 586 $44,250 $0.24166 $0.354 5.00

Mar-01 198,406 469 595 $48,714 $0.24553 $0.390 5.42

Apr-01 176,103 512 521 $32,155 $0.18259 $0.257 4.81

May-01 192,578 570 570 $23,557 $0.12233 $0.188 5.26

Jun-01 197,694 578 578 $24,082 $0.12181 $0.193 5.40

Jul-01 211,068 593 594 $25,307 $0.11990 $0.202 5.76

Aug-01 208,526 610 610 $25,400 $0.12181 $0.203 5.69

Sep-01 231,725 636 679 $27,731 $0.11967 $0.222 6.33

Totals 2,394,824 NA NA $427,608 N/A $3.421 65.39

Average 199,569 519 592 $35,634 $0.17855 $0.285 5.45

Cost savings are generally calculated using the average unit cost per utility. For example, the average costof electricity is calculated by dividing the total monthly cost, which includes demand costs and taxes, by themonthly consumption. However, some measures may not achieve any demand savings or may only effect



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off-peak demand usage, therefore these measures cannot use the average electricity cost described above toestimate cost savings. In addition, the energy commodity charge fluctuates from month to month and variesbased on time of use. The DOE-2 simulation model used the extensive time-out-use rate structure toestimate cost savings, however spreadsheet calculations utilized either an average cost $0.078/kWh when no

demand savings are available, or $0.1211/kWh when demand savings could be claimed. Electricitycommodity charges have lowered significantly over the past 6 months and appear to have stabilized.Therefore the average energy costs (both with and without demand costs) are based on the average for thepast 5 months, rather than including the extremely high rates from last summer. All costs includeappropriate taxes.

The electrical energy and demand profiles for the facility appear to be normal. Electrical consumption isreasonable for the City Z metropolitan area since the climate is fairly temperate and consistent. Since CityY is a bit inland from City Z, summer time temperatures are higher, hence the cooling increase duringsummer months. Since winter peak demand is only between 5 PM and 8 PM on weekdays (when thebuilding is basically unoccupied), the maximum non-coincident demand will be higher. During the summermonths, both demand values coincide with each other. Refer to the Monthly Electric Consumption andDemand graph located in Appendix B Utility History Analysis Figures.

END-USE BREAKDOWN

Figure 3 illustrates the energy consumption by various pieces of equipment at the facility.

Annual Energy Consumption by End-Use

Lighting

24.6%

Plugs & Equipment

24.5%

HP Fans

5.5%

Compressor Cooling

24.4%

Compressor Heating

0.1%

Loop Pumps and

Towers

18.3%

Exterior Lights

2.6%

Figure 3 End Use Breakdown



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FINDINGS, RECOMM ENDATIONS & IMPLEMENTATION

DETAILED FINDINGS

01 Scheduling and Programming Improvements

Finding Description

The CSI energy management system controls the water-source heat pump system by scheduling operation ofthe heat pumps, maintaining loop temperature, and controlling operation of the water loop circulation pumpsbased on heat pump status. Based on evaluation of the CSI control programming and through subsequentshort-term monitoring, the following issues were identified:

Several heat pumps were commanded on when the building is unoccupied;

Water loop circulation pumps ran continuously due to heat pump scheduling problems; and

Fluid cooler spray pumps ran during unoccupied times due to heat pump scheduling problems.

Heat Pump Scheduling Problems Scheduling problems identified in the CSI program include:

(1)The heat pumps serving Suites 300, 303, and 311 are all scheduled to operate until midnight onTuesdays

(2) The heat pumps serving Suite 717 are scheduled to operate until 8 PM Monday through Friday

(3)The heat pumps serving suite 602 are scheduled to operate from 7 AM to 6 PM on Sundays

(4)The heat pumps serving suite 513 are scheduled to operate until midnight on both Fridays and

Saturdays.

Short-term monitoring also detected several heat pumps operating over a holiday (Thanksgiving) as well asverifying many of the scheduling anomalies outlined above. Figure 4 illustrates the average load shape forall of the heat pumps monitored during a two-week period from November 15 through November 30.

The facility has a special meter that monitors electrical demand and energy consumption every 15 minutesand this data is collected and stored on the Utility web site. The following graphs were generated anddownloaded to provide additional insight into the overall building load profile. Figure 5 illustrates weekendand holiday load profiles, while Figure 6 and Figure 7 both demonstrate that there is equipment operatingduring unoccupied hours and both profiles are indicative of HVAC equipment satisfying a cooling load.



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All Monitored Heat PumpsAverage Daily Load Shapes

0

10

20

30

40

50

60

0:00

1:00

2:00

3:00

4:00

5:00

6:00

7:00

8:00

9:00

10:00

11:00

12:00

13:00

14:00

15:00

16:00

17:00

18:00

19:00

20:00

21:00

22:00

23:00

Power(kW)

Occupied Days Saturdays Sundays Holidays

UnnecessarySaturday andSunda o eration

ThanksgivingDay operation

Figure 4 Monitored heat pump average daily load shapes

Saturday. Note largeload after 12 PM

Sunday. Note loadwhen buildingshould beunoccupied

Monday. Labor Day holiday . Note load when

buildin should be unoccu ied

Figure 5 Weekend and Holiday Load Profile



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Heat pumps should bescheduled off at this time butbuilding load indicates alot ofequipment is still operating.

Figure 6 Typical Saturday Load Profile



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Building load begins to increase at about 8AM. The load profile is indicative of acoolin load

Figure 7 Typical Sunday Load Profile

Water Loop Pump Operation The water loop pumps serving the east and west loops are supposed to becommanded off through the CSI energy management system when the heat pumps are disabled. HoweverFigure 8 and Figure 9 both demonstrate that neither pump turned off during the entire 2-week monitoringperiod. One possible reason could be due to the heat pump schedule problems outlined above. Another

possibility is that the CSI system is not programmed correctly to achieve the desired control.



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0

50

100

amps

Cooling Tower Fan #2

0.0

10.0

amps

Cooling Tower - spray pump #2

0

10

20

11/15/01 11/17/01 11/19/01 11/21/01 11/23/01 11/25/01 11/27/01 11/29/01

amps

Date

Water loop pum p #4

Circulation pump serving the east loop did not shut offduring the entire 2-week monitoring period.

Figure 8 Water Loop Pump #4

0

15

30

amps

Water loop pump #2

0

1

2

3

amps

Cooling tower spray pump #1

0

30

60

amps

Cooling tower fan #1

40

60

80

100

11/15/01 11/17/01 11/19/01 11/21/01 11/23/01 11/25/01 11/27/01 11/29/01

F

Date

Ambient Temperature

Circulation pump serving the west loop did not shut off during-

Figure 9 Water Loop Pump #2

Fluid Cooler Spray Pump Operation The spray pump on each fluid cooler is controlled by the CSI systemto turn on when the corresponding loop temperature exceeds a minimum temperature and both spray pumpswere found to be operating during unoccupied hours as illustrated in Figure 10. A similar profile wasobserved for the east loop fluid cooler. The most likely explanation is that several heat pumps are operating



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during unoccupied hours and adding heat to the loop. Hence the fluid cooler fans and spray pumps willoperate to maintain loop temperature.

West Loop Fluid Cooler Fan and Spray Pump

Average Daily Load Shapes

0.0

0.5

1.0

1.5

2.0

2.5

0:00 1:00 2:00 3:00 4:00 5:00 6:00 7:00 8:00 9:0010:0011:0012:0013:0014:0015:0016:0017:0018:0019:0020:0021:0022:0023:00

Power(kW)

CT Fan, Weekdays

CT Fan, Unoccupied Days

Spray Pump, Weekdays

Spray Pump, Unoccupied Days

Note that both the coolingtower fan and spray pumpoperate on weekends whens stems should be off

Spray pumps operatewhen cooling tower fans

are off and building isunoccu ied

Systems shouldbe off at 12 PM onSaturdays

Figure 10 Fluid Cooler Fan and Spray Pump Operation

Recommendation

Having individual heat pumps operate during normally unoccupied hours of the day or week requires that

the entire water loop system must also operate, including the fluid coolers and water loop pumps, simply tosupport these individual units. To eliminate this very inefficient operation, all heat pump units should beprogrammed with the same schedule, namely from 6 AM to 6 PM Monday through Friday, and 8 AM to 12PM Saturday (as most of them currently are scheduled), with individual schedules modified as necessary tomeet special requirements. The key is to remove any reference to Sunday operation and minimizeunnecessary operation. Furthermore, only Christmas Day, the Fourth of July, and New Years Day arecurrently programmed into the system as holidays. This holiday schedule should be reviewed and expandedif possible to include additional days.

The CSI system is equipped with building manager, a feature that allows occupants to call into theautomated system and request cooling during normally unoccupied hours. The system documents the run

time requested for cooling, and issues a monthly report that can then be used to charge the occupants basedon a defined rate. This system should be reviewed and reincorporated to handle off-hour cooling andheating needs. A rate will need to be established for this off-hour service, keeping in mind that it will needto include expenses based on central plant (tower and pump) operation.

The current controls are also set to run the water loop pumps whenever any of the heat pumps call forcooling. This is done by the CSI system tracking heat pump statuses, then enabling the appropriate loop



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pump based on whether any heat pump status is enabled. The control sequence should be changed so thatCSI can schedule pump operation directly, rather than be based on heat pump status. This schedule shouldbe based on the same schedule as the heat pumps, and would be accomplished by simply reprogrammingCSI and should be linked so that any short-term special event schedule changes made to any heat pump will

also be recognized by the loop pump schedule.

The spray pumps are currently programmed to operate whenever the loop water temperature is above 79Fand the fans cycle on and off to maintain loop temperature at 85F. We believe that this control strategy isadequate and the fans and pumps would tend to shut off if the schedule changes outlined above areimplemented. However, even when all of the heat pumps are turned off, there will be residual heat in theloop, which can cause both to cycle during unoccupied hours. To eliminate this unnecessary operation, werecommend controlling the spray pumps and fans based on temperature during occupied hours andcommanding them off by a schedule during unoccupied hour. Again this schedule should be linked with theheat pump and loop pump schedules so that the fluid coolers will operate correctly whenever the rest of thesystem is enabled. Detailed calculation for this measure is provided in the spreadsheet entitled Schedulingand Programming Improvements located in Appendix G Savings and Cost Estimates. Note energy andcost savings have been revised, if necessary, based on actual data gathered during post-retrofit measurementand verification (refer toMeasurement & Verification of Savings section of the report for details). Inaddition, the implementation cost has been revised to reflect actual contractor invoices, if applicable.

Estimated Economic Impact SummaryEstimated Annual Electrical Energy Savings - 219,460 kWh/yr Estimated Annual Cost Savings - $17,118Estimated Electrical Peak Demand Savings - 0 kW Estimated Implementation Cost - $243

Estimated Annual Natural Gas Savings - 0 Therm/yr Simple Payback (yrs) - 0.0

Implementation Plan

The schedules for each heat pump unit should be reviewed and reprogrammed to correspond to theaforementioned general schedule. Operation of the building manager feature should also be reviewed andreincorporated into the system. A rate will need to be established for off-hour service, which includesexpenses based on both individual heat pump and central plant (tower and pump) operation.

The water loop pump control logic should be reprogrammed in the CSI system so that the pumps respond toa direct scheduled start/stop command from CSI, and not from heat pump status. Coordination between theheat pump schedules and loop pump schedules should be made so that special schedule changes can bemade with ease and both systems will respond accordingly. Correct wiring must be verified to insure thatthe CSI digital outputs for pump start/stop can be directly wired to the magstarters of the pumps forcomplete control of each pump.

A controls contractor should perform all work. Costs are associated with reprogramming the heat pumpschedules in the CSI system, as well as time to evaluate and reintroduce the building manager feature intothe system. Implementation cost has been estimated based on 40 hours of programming at a rate of $100per hour, including contractor overhead and profit and contingency.



27/71


Further Investigation Required by PECI Under Current Scope - No No, or Low Capital Expenditure to Implement - YFurther Study or Engineering Needed Outside Current Scope - No Significant Capital Expenditure to Implement - Further Investigation/Testing Required by the Owner - No Savings Calculation Method - Simulation/worksheFollow-Up By PECI Required to Implement Under Current Scope - No Identification Method - Analysis of monitoring da

Owner Action TakenAll heat pump operating schedules programmed in the CSI energy management system were reviewed andmodified as necessary. In general, most heat pumps will operate from between 6 AM and 7 AM until 6 PMMonday through Friday, and some units from 8 AM to 12 PM Saturday, with individual schedules modifiedas necessary to meet special requirements. The schedule changes also effect the operation of both East andWest water loop circulation pumps as well as each fluid cooler fan and spray pump, which all have beenprogrammed to operate only when a heat pump is scheduled to operate.

02 Rewire Heat Pump Supply Fans

Finding Description

The monitored data suggest that the supply fans on the individual heat pumps operate regardless of whetherthe units compressor is enabled or not through the CSI energy management system. This behavior wasobserved on most heat pumps, during both occupied and unoccupied hours of operation. Some supply fansappeared to operate continuously (refer to Figure 11), while a majority tended to cycle on and off during theunoccupied hours even though the heat pumps was commanded off (refer to Figure 12 as a representativesample). The cycling phenomenon was verified during the site visit by adjusting a thermostat to call forcooling during an unoccupied period. The CSI system had commanded the heat pump off and it stayed offregardless of the setpoint, yet the supply fan turned on. We suspect that most of the supply fans andthermostats are wired in such a manner that the supply fan will always cycle on if the thermostat calls foreither heating or cooling.



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1.0

1.5

2.0

2.5

3.0

0 2 4 6 8 10 12 14 16 18 20 22 24

UnitPower(kW)

Hour

Heat Pump, 1s t Floor

Supply fan andcompressor on

Supply fan always on

Figure 11 Heat pump operation, 1stfloor

0

50

amps

Heat Pumps, 5th Floor 38,45,?

0

10

20

amps

Heat Pumps, 5th Floor 35,36,44

0

10

20

30

11/15/01 11/17/01 11/19/01 11/21/01 11/23/01 11/25/01 11/27/01 11/29/01

amps

Date

Heat Pumps, 5th Floor 41,42,43

Note fans cycling duringunoccu ied hours.

Figure 12 Heat Pump Supply Fan Cycling



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RecommendationThe relays are currently wired at each heat pump such that when CSI turns the unit off according to itsprogrammed schedule, only the compressor is disabled. Thus, signals for cooling or heating coming fromthe thermostat during unoccupied hours allow the supply fan to turn on. Since the water loop pumps are

programmed to turn on whenever a heat pump is operating, this also causes the pumps to turn on (which iswhy the pumps currently operate continuously). The relays should be rewired at each heat pump so that theentire unit is disabled by the CSI signal, and not just the units compressor. Detailed calculation for thismeasure is provided in the spreadsheet entitledRewire Heat Pump Supply Fans located in Appendix G Savings and Cost Estimates. Note energy and cost savings have been revised, if necessary, based onactual data gathered during post-retrofit measurement and verification (refer toMeasurement & Verificationof Savings section of the report for details). In addition, the implementation cost has been revised to reflectactual contractor invoices, if applicable.

Estimated Economic Impact SummaryEstimated Annual Electrical Energy Savings - 66,405 kWh/yr Estimated Annual Cost Savings - $5,180Estimated Electrical Peak Demand Savings - 0 kW Estimated Implementation Cost - $8,531

Estimated Annual Natural Gas Savings - 0 Therm/yr Simple Payback (yrs) - 1.6Implementation PlanAll heat pumps within the facility should have their individual relays rewired so that the entire unit isdisabled by the CSI signal, and not just the units compressor. To implement this, wire the power wire (red,24VAC+) that supplies electricity to the thermostat through a normally open relay contact. This relay is wilthen be energized or de-energized through the CSI system to enable and disable the heat pump. The relaycontact is located between the low voltage transformer and the thermostat, and therefore will disconnect allpower for the thermostat when the CSI system schedules the heat pump to be disabled. This will in-turndisable the fan, heat and cooling operation of the heat pump.

The work should be performed by a controls contractor. Costs associated with rewiring the relay at eachindividual heat pump unit are estimated 45 minutes per unit, a total of 175 units and a labor cost of $65 perhour, which includes contractor overhead and profit (fromRS Means Electrical Cost Data).

Further Investigation Required by PECI Under Current Scope - No No, or Low Capital Expenditure to Implement - YFurther Study or Engineering Needed Outside Current Scope - No Significant Capital Expenditure to Implement - Further Investigation/Testing Required by the Owner - No Savings Calculation Method - SpreadsheFollow-Up By PECI Required to Implement Under Current Scope - No Identification Method - Analysis of monitoring da

Owner Action Taken

This measure was not implemented by the owner.

03 Install Variable Frequency Drives on Fluid Cooler Fans

Finding DescriptionThe original fluid coolers had 2-speed fan motors but both fluid coolers were replaced recently and cameequipped with single-speed fan motors. As a result the fan motors short cycle continually to maintain water



30/71


loop temperature. The on-cycle for each fan was measured to be shorter than one minute at times during thesite visit. This kind of short cycling is extremely hard on the motors, belts, and motor starters.

Recommendation

Both fluid cooler fans should be equipped with variable frequency drives (VFDs). This will allow the fanmotors to modulate according to heat rejection loads presented by the water loop, reducing energyconsumption. This measure is mutually exclusive with Finding 04 Install Two-speed Motors on FluidCooler Fans. Energy savings were calculated using DOE-2 hourly simulation program. Non-energy costsavings can be realized by installing a VFD if frequent fan cycling leads to premature belt, motor, or starterfailure. Note energy and cost savings have been revised, if necessary, based on actual data gatheredduring post-retrofit measurement and verification (refer toMeasurement & Verification of Savings sectionof the report for details). In addition, the implementation cost has been revised to reflect actual contractorinvoices, if applicable.

Estimated Economic Impact Summary

Estimated Annual Electrical Energy Savings - 28,000 kWh/yr Estimated Annual Cost Savings - $3,000Estimated Electrical Peak Demand Savings - 0 kW Estimated Implementation Cost - $10,000Estimated Annual Natural Gas Savings - 0 Therm/yr Simple Payback (yrs) - 3.3

Implementation PlanEach fluid cooler fan should have a 25-hp variable frequency drive (VFD) installed to control each fanmotor. In addition each VFD should be connected to the CSI system. This may require an additionalcontroller if space on the existing controllers is inadequate.

This work should be performed by an HVAC contractor. Costs include purchase and installation of the twodrives and the associated controller, including taxes, contractor overhead and profit.

Further Investigation Required by PECI Under Current Scope - No No, or Low Capital Expenditure to Implement - Further Study or Engineering Needed Outside Current Scope - No Significant Capital Expenditure to Implement - YFurther Investigation/Testing Required by the Owner - No Savings Calculation Method - DOE-2 model analyFollow-Up By PECI Required to Implement Under Current Scope - No Identification Method - Analysis of monitoring da

Owner Action Taken


04 Install Two-Speed Motors on Fluid Cooler Fans

Finding Description

The original fluid coolers had 2-speed fan motors but both fluid coolers were replaced recently and cameequipped with single-speed fan motors. As a result the fan motors short cycle continually to maintain waterloop temperature. The on-cycle for each fan was measured to be shorter than one minute at times during thesite visit. This kind of short cycling is extremely hard on the motors, belts, and motor starters.



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RecommendationBoth fluid cooler fans should be equipped with 2-speed fan motors. This will allow the fan motors toalternate between low speed and high speed according to heat rejection loads presented by the water loop,reducing energy consumption. This measure is presented as an alternative to, and mutually exclusive with,

Finding 03 Install Variable Frequency Drives on Fluid Cooler Fans .

Energy savings were calculated using DOE-2 hourly simulation program. Non-energy cost savings can berealized by installing a two-speed motor if frequent fan cycling leads to premature belt, motor, or starterfailure. Note energy and cost savings have been revised, if necessary, based on actual data gatheredduring post-retrofit measurement and verification (refer toMeasurement & Verification of Savings sectionof the report for details). In addition, the implementation cost has been revised to reflect actual contractorinvoices, if applicable.

Estimated Economic Impact SummaryEstimated Annual Electrical Energy Savings - 16,000 KWh/yr Estimated Annual Cost Savings - $1,690Estimated Electrical Peak Demand Savings - 0 KW Estimated Implementation Cost - $14,100


Implementation PlanA 25 HP two-speed motor should be installed on each fluid cooler fan. In addition each motor should beconnected to the CSI system. This may require an additional controller if space on the existing controllers isinadequate. This work should be performed by an HVAC contractor. Costs include purchase andinstallation of the new two-speed motors, including taxes, contractor overhead and profit.


Owner Action Taken

This measure was implemented in conjunction with reducing the condenser water loop temperature. Referto Finding 06 Reduce Condenser Water Loop Temperature and Install Two-speed Motors for details.

05 Reduce Condenser Water Loop Temperature

Finding DescriptionThe CSI energy management modulates the fluid cooler fan and spray pump to maintain water looptemperature leaving each fluid cooler at 85F. Short-term monitoring verified that the outlet water

temperature for both the east and west loops ranged from 83F to 88

F when the fluid coolers are operating.

Inlet water temperatures range from 87F to 91F.

RecommendationReducing the condenser water loop temperature set point from 85F to 75F will improve the individualheat pump compressor operating efficiencies. According to the heat pump manufacturers literature,

entering condenser water temperature can range from 95F to 60F. The improved compressor operating



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efficiencies will result in electrical energy consumption and demand savings. As a consequence, fluidcooler fan operation will increase in order to provide the colder water, however, the efficiency improvementfor all 175 heat pumps will far outweigh any fan energy increase. The measure is mutually exclusive withFinding 06 Reduce Condenser Water Loop Temperature and Install Two-speed Motors and Finding 07

Reduce Condenser Water Loop Temperature and Install Variable Frequency Drives. Energy and demandsavings were calculated using DOE-2 hourly simulation program. Several model runs were made at 2Fincrements from current setpoint of 85F to 67F do develop a family of curves from which energy,demand, and cost savings can be interpreted. These curves, entitled Water Loop Temperature Reset EnergySavings and Water Loop Temperature Reset Demand Savings can be found in Appendix G Savings andCost Estimates. Note energy and cost savings have been revised, if necessary, based on actual datagathered during post-retrofit measurement and verification (refer toMeasurement & Verification of Savingssection of the report for details). In addition, the implementation cost has been revised to reflect actualcontractor invoices, if applicable.

Estimated Economic Impact Summary

Estimated Annual Electrical Energy Savings - 20,000 KWh/yr Estimated Annual Cost Savings - $2,800Estimated Electrical Peak Demand Savings - 4 KW Estimated Implementation Cost - $50Estimated Annual Natural Gas Savings - 0 Therm/yr Simple Payback (yrs) - 0.0

Implementation PlanThe condenser water loop temperature set points should be reprogrammed from 85F to 75F within the CSIenergy management system. The work should be performed by a controls contractor. Implementation costhas been estimated based on 4 hours of programming at a rate of $100 per hour.

Further Investigation Required by PECI Under Current Scope - No No, or Low Capital Expenditure to Implement - YFurther Study or Engineering Needed Outside Current Scope - No Significant Capital Expenditure to Implement - Further Investigation/Testing Required by the Owner - No Savings Calculation Method - DOE-2 model analyFollow-Up By PECI Required to Implement Under Current Scope - No Identification Method - Analysis of monitoring da

Owner Action Taken

This measure was implemented in conjunction with installation of two-speed fluid cooler fan motors. Referto Finding 06 Reduce Condenser Water Loop Temperature and Install Two-speed Motors for details.

06 Reduce Condenser Water Loop Temperature and Install Two-speed Motors

Finding DescriptionCSI energy management modulates the fluid cooler fan and spray pump to maintain water loop temperature

leaving each fluid cooler at 85F. Short-term monitoring verified that the outlet water temperature for boththe east and west loops ranged from 83F to 88F when the fluid coolers are operating. Inlet water

temperatures range from 87F to 91F.

RecommendationThis measure is presented as an alternative to Finding 05 Reduce Condenser Water Loop Temperature.

Reducing the condenser water loop temperature set point from 85F to 75F will improve the individual



33/71


heat pump compressor operating efficiencies. According to the heat pump manufacturers literature,

entering condenser water temperature can range from 95F to 60F. The improved compressor operatingefficiencies will result in electrical energy consumption and demand savings. As a consequence, fluidcooler fan operation will increase in order to provide the colder water, however, the efficiency improvement

for all 175 heat pumps will far outweigh any fan energy increase. The measure also includes installing two-speed motors for better fan modulation in order to maintain loop temperature setpoint. The measure ismutually exclusive with Finding 05 Reduce Condenser Water Loop Temperature and Finding 07 Reduce Condenser Water Loop Temperature and Install Variable Frequency Drives. Energy and demandsavings were calculated using DOE-2 hourly simulation program. Several model runs were made at 2Fincrements from current setpoint of 85F to 67F do develop a family of curves from which energy,demand, and cost savings can be interpreted. These curves, entitled Water Loop Temperature Reset EnergySavings and Water Loop Temperature Reset Demand Savings can be found in Appendix G Savings andCost Estimates. Note energy and cost savings have been revised, if necessary, based on actual datagathered during post-retrofit measurement and verification (refer toMeasurement & Verification of Savingssection of the report for details). In addition, the implementation cost has been revised to reflect actual

contractor invoices, if applicable.



Implementation PlanThe condenser water loop temperature set points should be reprogrammed from 85F to 75F within the CSIenergy management system. The work should be performed by a controls contractor. Implementation costhas been estimated based on 4 hours of programming at a rate of $100 per hour. In addition, installation oftwo 25 HP two-speed motors will be performed by an HVAC contractor. Costs include purchase and

installation of the new two-speed motors, including taxes, contractor overhead and profit.


Owner Action Taken

The owner elected to reduce the condenser water loop temperature and install two-speed fan motors on eachfluid cooler. Both measures are combined into one due to the significant interaction each measure imposeson overall energy savings.

The East and West fluid coolers were both retrofitted with new 25 HP, two-speed motors and motor startersand programmed to operate with the same schedule as the heat pumps. In addition, the following controlstrategy was programmed into the CSI energy management system to reduce the water loop temperatureleaving each fluid cooler:

Each spray pump operates to maintain water temperature at 74F



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Each fan operates at low-speed to maintain water temperature at 75F

Each fan operates at high-speed to maintain water temperature at 80F

The reduction in condenser water temperature is not as large as originally recommended, therefore energy

and cost savings for this measure have been adjusted to reflect actual temperatures programmed into the CSIenergy management system.

07 Reduce Condenser Water Loop Temperature and Install VariableFrequency Drives

Finding DescriptionCSI energy management modulates the fluid cooler fan and spray pump to maintain water loop temperatureleaving each fluid cooler at 85F. Short-term monitoring verified that the outlet water temperature for both

the east and west loops ranged from 83F to 88F when the fluid coolers are operating. Inlet water

temperatures range from 87F to 91F.

RecommendationThis measure is presented as an alternative to Finding 05 Reduce Condenser Water Loop Temperature.

Reducing the condenser water loop temperature set point from 85F to 75F will improve the individualheat pump compressor operating efficiencies. According to the heat pump manufacturers literature,

entering condenser water temperature can range from 95F to 60F. The improved compressor operatingefficiencies will result in electrical energy consumption and demand savings. As a consequence, fluidcooler fan operation will increase in order to provide the colder water, however, the efficiency improvementfor all 175 heat pumps will far outweigh any fan energy increase. The measure also includes installingvariable frequency drives for infinite fan modulation in order to maintain loop temperature setpoint. Themeasure is mutually exclusive with Finding 05 Reduce Condenser Water Loop Temperature and Finding06 Reduce Condenser Water Loop Temperature and Install Two-speed Motors. Energy and demandsavings were calculated using DOE-2 hourly simulation program. Several model runs were made at 2Fincrements from current setpoint of 85F to 67F do develop a family of curves from which energy,demand, and cost savings can be interpreted. These curves, entitled Water Loop Temperature Reset EnergySavings and Water Loop Temperature Reset Demand Savings, can be found in Appendix G Savings andCost Estimates. Note energy and cost savings have been revised, if necessary, based on actual datagathered during post-retrofit measurement and verification (refer toMeasurement & Verification of Savingssection of the report for details). In addition, the implementation cost has been revised to reflect actualcontractor invoices, if applicable.



Implementation PlanThe condenser water loop temperature set points should be reprogrammed from 85F to 75F within the CSIenergy management system. The work should be performed by a controls contractor. Implementation cost



35/71


has been estimated based on 4 hours of programming at a rate of $100 per hour. In addition, installation oftwo 25 HP variable frequency drives will be performed by an HVAC contractor. Costs include purchaseand installation of the new VFDs, including taxes, contractor overhead and profit.

Further Investigation Required by PECI Under Current Scope - No No, or Low Capital Expenditure to Implement -

Further Study or Engineering Needed Outside Current Scope - No Significant Capital Expenditure to Implement - YFurther Investigation/Testing Required by the Owner - No Savings Calculation Method - DOE-2 model analyFollow-Up By PECI Required to Implement Under Current Scope - No Identification Method - Analysis of monitoring da

Owner Action Taken


08 Trim West Loop Pump Impeller

Finding DescriptionThe west end water loop is served by a 20 HP pump and design for the loop is 600 GPM at 84 feet of head.

During the site visit, pump discharge and suction pressures were measured and determined to be operatingat 75 feet of head. Based on the pump curve for the nameplate impeller size, it is estimated that the pump iscurrently delivering approximately 750 GPM through the loop. A significant amount of energy is wasted bycirculating more water through the system than is required by the heat pumps since pipe friction losses are a

function of the square of the velocity ( hl V2). A 50% reduction in velocity reduces friction loss to 25% of

their original values.

RecommendationThe recommendation is made to trim the impeller to a size that will deliver design flow rate with the mainbalancing valve wide open. A no-flow test was performed by facility maintenance personnel. This testverified the impeller size listed on the nameplate is correct at 9.5 inches. Therefore, the system evaluation is

based on the nameplate impeller size. Currently the balancing valve is wide open and net head developedby the pump was measured at 75 feet. This corresponds to approximately 750 GPM or water flow. Pumpcurve analysis predicts that design flow could be achieved with a 7.6 inch impeller, but the smallest impellerthan can be used in the pump is 8 inch. Therefore energy savings are based on using an 8-inch impeller.Detailed calculation for this measure is provided in the spreadsheet entitled Trim West Loop Pump Impellerlocated in Appendix G Savings and Cost Estimates. Since both demand and energy savings will occur, theaverage energy cost of $0.1211/kWh, which includes all taxes and demand costs, was used to estimate costsavings. Note energy and cost savings have been revised, if necessary, based on actual data gatheredduring post-retrofit measurement and verification (refer toMeasurement & Verification of Savings sectionof the report for details). In addition, the implementation cost has been revised to reflect actual contractorinvoices, if applicable.

Estimated Economic Impact SummaryEstimated Annual Electrical Energy Savings - 19,890 KWh/yr Estimated Annual Cost Savings - $2,409Estimated Electrical Peak Demand Savings - 6.0 KW Estimated Implementation Cost - $2,426



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