cold-climate research round-up

Cold-Climate Research Round-Up

A Bi-Annual Webinar Series | Center for Energy & Environment and Seventhwave

On the ground impacts & opportunities for leading edge, clean energy technologies & services.

The PurposeA semi-annual webinar series to share leading field research & expertise on efficient and clean energy solutions, particularly relevant for cold climate applications.

Next webinar: July 2017

Our Expertise• Conduct primary research in the field• Produce market characterizations & potential studies• Provide training & engagement to convey new info• Provide services and consulting to entities that are looking to

increase clean energy & conservation

CEE | 8 Dedicated research staff Seventhwave| 5 dedicated research staff

Today’s Round-Up• Commissioning for daylighting controls • Optimizing operation of buildings with indoor pools• Energy Recovery Ventilation effectiveness• Maximizing energy savings from Demand Control Ventilation• Cold-Climate Variable Refrigerant Flow optimization• Innovative aerosol envelope sealing • Next generation Air Source Heat Pumps • Hybrid geothermal achieves highest performance

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Many of these projects were supported by a grant funds from the MN Department of Commerce, Division of Energy Resources through the Conservation Applied Research and Development (CARD) program.

Today’s Round-Up• Commissioning for daylighting controls | Seventhwave• Optimizing operation of buildings with indoor pools• Energy Recovery Ventilation effectiveness• Maximizing energy savings from Demand Control Ventilation• Cold-Climate Variable Refrigerant Flow optimization• Innovative aerosol envelope sealing• Next generation Air Source Heat Pumps • Hybrid geothermal achieves highest performance

Today’s Round-Up• Commissioning for daylighting controls • Optimizing operation of buildings with indoor pools | CEE• Energy Recovery Ventilation effectiveness | CEE• Maximizing energy savings from Demand Control Ventilation• Cold-Climate Variable Refrigerant Flow optimization• Innovative aerosol envelope sealing• Next generation Air Source Heat Pumps • Hybrid geothermal achieves highest performance

Areas of expertise: Energy efficiency programs Field research Market characterization High performance design Education and training

Commissioning for Daylighting

Controls

Minnesota Conservation Applied Research and Development (CARD) Grant Program

Background and Objective

1. Photosensor

2. Controller

3. Dimming Unit

Research Approach

Monitored 20 spaces across 10 buildings

Period 1 Energy

Period 1 Savings

Current without

photocontrol

Period 3 Energy

Period 3 Savings

Results and Recommendations

23% savings before Cx, increased to 43% with Cxseventhwave.org/mndaylighting

Research

Financing Policy

Programs

Discover + Deploy the most effective solutions for a healthy, low-carbon economy

Planning & Consulting

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Optimizing Indoor Public PoolsA high energy intensity area with specialty HVAC systems

Russ Landry P.E. | Senior Mechanical Engineer

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Indoor Public PoolsWhy we took a look | We’ve seen big energy saving opportunities in other facilities with specialized HVAC systems, such as ice arenas.

Research Objective | Determine energy cost savings from improvements & develop guides for operators and recommissioning providers.

Extent of Project Efforts• Literature review & identification of indoor public pools in Minnesota• Surveys of 30 sites• Recommissioning and savings verification for 5 sites• Guides for pool operators and recommissioning providers.

Notable Previous Work• Pool operator certification manuals• DOE sponsored RSPEC! software

Conducted Jan 2014 – May 2017

Indoor Public Pool Optimization

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Technology in Brief


Pool Water Heating & Filtering

Space Ventilation, Heating & Dehumidification

84°F 55% RH

82°F

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Headline Findings & Observations

Energy & Cost Savings• Some consistent, “prescriptive” type opportunities• Site-specific control & operational “problems”• Some “common wisdom” not true for cold climates• Biggest savings for heating fuel (some electric hvac)

Barriers to Field Implementation• Contractor & manufacturer execution of control details• Often poor BAS link with HVAC & pool water heating• User & operator upkeep: cover & controls

Bright Spots & Opportunities • Cover• Cost-effective control fixes


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Highlights of Preliminary Savings


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Benefits Beyond Energy

Building Operators• Reduced Comfort Complaints• Simple Actions with Clear Directions from Operations Guide

Building Owners• Reduced Comfort Complaints• Equipment Longevity• Facility Longevity


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How to Use This Information

How you can use this information today, take action, or access more tools…• www.mncee.org/pool• http://smartenergy.arch.uiuc.edu• http://www.rlmartin.com/rspec/software.htm


http://www.mncee.org/pool

http://smartenergy.arch.uiuc.edu/

http://smartenergy.arch.uiuc.edu/

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Energy Recovery in Commercial and Institutional BuildingsDo energy recovery systems meet performance expectations?

Josh Quinnell Ph D | Senior Research Engineer


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C&I Energy RecoveryWhy we took a look • Anecdotal impression that ERVs may not live up to savings potential

Research Objective • Characterize ERVs in Minnesota, determine extent of problems, study a

subset of representative ERVs in detail

Extent of Data Collected • Data collected on 400 commercial & institutional ERVs• Screened 30 ERVs for study• Selected 9 units for detailed study, measurements, and long term monitoring

Notable Previous Work • Prior work is design focused, usually on the cooling side • Stops short of the practical issues associated with expectations, installation,

and operations

Conducted Jan 2014 – Dec 2016

Commercial and Institutional Energy Recovery

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Exhaust Air-to-Air Energy Recovery Ventilation (ERV) in Brief

• Purpose: Transfer energy between exhaust air and outside air to lower energy load of building ventilation

• Relevance: Increasing code requirements

• Performance Expectations:• 40 - 85% heating savings• 0 – 20 % cooling savings


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General Findings & Observations

Expectations: ERVs are just another HVAC system• Properly designed, installed, and operated ERVs typically achieve

design performance

Reality: Barriers to ERV Performance are practical• There are no consistent expectations for ERV performance • 80% of the problems occur during installation or operation• Problems persist because expectations aren’t established and

other HVAC systems compensate

Opportunity: Most lost recovery is an easy fix• A small number of issues were responsible for the vast majority of

energy penalties


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Problems on ERV systems• 75 issues discovered and 51 corrected• Energy savings increased $40,683 -> $57,851 for 9 units or 0.30

to 0.42 $/supply-cfm• 15% of issues responsible for 92% of lost energy recovery

Control se

quence

Neglected m

aintenance

Installa

tion issue

Communication

Sensors

Part fa

ilure

Setpoint

Operator overr

ide

Design iss

ue

Off design operation

Schedulin

g0

2

4

6

8

10

12

Freq

uenc

y

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Problems Encountered on ERVs


High functioning units – 33% units / 8% problems• Design-bid-build projects• Robust documentation & commissioning process• Typically found only neglected maintenance items

Functioning units – 33% units / 38% problems• Awareness of minor problems, frustration or confusion about unit

operation• Odd sequencing, BAS issues, sensor, scheduling, and set point problems

Dysfunctional units – 33% units / 53% problems• Awareness of minor problems, no awareness of major ones• Heat recovery casually disabled and poor installation

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Opportunities


Text book examples of ERV applications are common!• We know that dramatic energy savings are possible in practice• Robust documentation, commissioning, and hand off are key to success• Improving general maintenance is still an opportunity for the best systems

Most problems don’t seriously inhibit energy recovery!• Consistent with the types of problems reported outside this work• There is still a huge opportunity; these problems indirectly impact

expectations and impressions of energy recovery –typically unrelated to actual recovery performance

It’s easy to identify dysfunctional units!• If a unit runs 5 ᵒF– 45ᵒF and above 75ᵒF, 85% savings are achieved• In many situations it is easy to casually disable energy recovery, but it’s also

easy to re-enable it and perform basic training about specific controls

Today’s Round-Up• Commissioning for daylighting controls • Optimizing operation of buildings with indoor pools • Energy Recovery Ventilation effectiveness • Maximizing energy savings from DCVs | Seventhwave• ccVariable Refrigerant Flow optimization | Seventhwave• Innovative aerosol envelope sealing• Next generation Air Source Heat Pumps • Hybrid geothermal achieves highest performance

Maximizing Energy Savings from Demand

Control Ventilation



Sensor

VAV Boxes

Central and/or Zone Control

AHU

Source: http://i.stack.imgur.com/4WKDC.jpg

SAOA

RA

Research Approach

96 systems around Minnesota


seventhwave.org/dcv

• Most room for improvement was found in basic design

• Proper commissioning (or recommissioning) has a significant impact on its performance

• Identifed four key program opportunities

Cold-Climate Variable

Refrigerant Flow Optimization

Research Approach

o What should the mechanical room setpoint be?o How to operate louvers?o Should supplemental heating be natural gas or electric?o What is the optimal defrost strategy?o How to handle condensate from supplemental heater?

Energy Balance Energy Consumption1. Outdoor units

• heating and/or cooling2. Supplemental heating3. Auxiliary heating

• baseboard4. Mechanical room

ventilation fan


OptimalThe optimal mechanical room setpoint occurs at a temperature close to, but higher than, the temperature at which the VRF system’s heating efficiency and capacity are significantly reduced.

o Supplemental heating should be provided by natural gas.o Demand defrost saves 4% of VRF energy as compared

to timed defrost.

seventhwave.org/cold-climate-vrf

Today’s Round-Up• Commissioning for daylighting controls • Optimizing operation of buildings with indoor pools • Energy Recovery Ventilation effectiveness • Maximizing energy savings from Demand Control Ventilation• Cold-Climate Variable Refrigerant Flow optimization• Innovative aerosol envelope sealing | CEE• Next generation Air Source Heat Pumps | CEE• Hybrid geothermal achieves highest performance

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Aerosol SealingA new building envelope technology for renovation & new construction projects

Dave Bohac P.E. | Director of Research


Partners

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Multifamily Aerosol SealingWhy we took a look • Proven duct sealing technology. UC Davis/WCEC performed lab tests

and limited demonstration for envelope sealing

Research Objective • Demonstrate leakage reduction in multifamily buildings and refine sealing

protocol

Extent of Data Collected • Sealed 16 units in 3 new construction buildings• Sealed 9 units in 3 existing buildings• Modeled energy savings and air flow impacts

Conducted Jan 2014 – July 2016

Aerosol Envelope Sealing of Multifamily Buildings

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Aerosol Envelope Sealing – How Does it Do That?• Pressurize apartment• Spray air sealing fog


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Air Sealing Results: New Construction


• Average leakage reduction of 81%

• Average leakage = 0.7 ACH50 after sealing

• All units at least 80% tighter than EPA ENERGY STAR requirement of 0.3 CFM50/sf

• Half of the units met 0.6 ACH50 passive house standard

• 69 therms/yr savings (3 to 0.6ACH50 reduction)

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What Gets Sealed?


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What Gets Sealed?


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Air Sealing Results: Existing Buildings


• Median leakage reduction of 75%

• Medain pre-leakage of 13.7 ACH50 reduced to 3.2 ACH50

• 60 to 200 therms/yr savings depending on existing leakage

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Non-Energy Benefits• Improved IAQ from reduced air transfer between units

• Reduced sound transmission between neighbors and outdoors

• More reliable method for meeting tightness requirements and test is part of service


Mechanical ventilation required after sealing and balanced ventilation needed for tighter units

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Future Work• Final report available soon

• DOE Building America: integrate sealing into new house construction process

• WCEC – Department of Defense large building sealing

• Aeroseal has started commercial work and developing contractor network Q4 2017


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Next generation Air Source Heat Pumps Are the new generation of air source heat pumps a good fit for cold climate heating?

Ben Schoenbauer | Senior Mechanical Engineer

Partner

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Field Assessment of Cold-Climate Air Source Heat Pumps (ccASHPs)Why we took a look • Technological advancements have expanded the applicable climates• Potential to serve an under-represented sector

Research Objective• Characterize system performance and installation challenges • Assess the implications to policy and programs

Extent of Data Collected• Data collected in 6 homes over 2 heating seasons

Notable Previous Work • Research and program development in “cool” climates (NE and NW)

Conducted Jan 2015 – Aug 2017

ccASHPs

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ccASHPs in Brief

• Technology Purpose: To provide energy efficient space conditioning through the transfer of heat between the exterior and interior of a home (a.k.a. an alternative primary source)

• Applications: Potential to meet the needs of an under- served group (homes heated with delivered fuels or electricity)

• Expectations: 1.5x or larger increase to space heating COP while maintaining comfort

ccASHP

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Findings & Observations

Expectations and Concerns• Can ASHP really transfer heat at cold outdoor conditions?

Reality from the FieldccASHPs provide benefits down to and beyond 10 ⁰ F, including:

• COPs more than 1.5x as efficient as baseline systems• Sufficient capacities to meet the heating loads of most MN homes• Sufficient airflow and temperatures to condition most homes comfortably

Opportunity for the Future• Integration with existing systems• Initial costs• Eliminate or minimize the need to backup

ccASHP

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Bright Spots & Opportunities• Site energy savings• Energy cost reductions• Reduced reliance of delivered fuels and/or peak electricity

Benefits Beyond Energy • Opportunities to serve in rural communities

How You Might Use this Information• Utilities:

• Heating rebates & programs that service this technology

• Contractors: • A signal that new gen products are appropriate in MN & guidance on when

• Architects & Engineers: • Consider as viable technology in all parts of MN

ccASHP

Today’s Round-Up• Commissioning for daylighting controls • Optimizing operation of buildings with indoor pools • Energy Recovery Ventilation effectiveness • Maximizing energy savings from Demand Control Ventilation• Cold-Climate Variable Refrigerant Flow optimization• Innovative aerosol envelope sealing • Next generation Air Source Heat Pumps • Hybrid geothermal achieves highest performance | Seventhwave

Hybrid Geothermal

Achieves Highest

Performance


Example system Cooling dominated Coupled hydronic loops Series supplemental device Dedicated supplemental pump

Research Approach

Cashman Equipment (cooling dominant)300k ft2 equipment dealer in Henderson, NV

East Career and Technical Academy (cooling dominant)250k ft2 vocational high school in Las Vegas, NV

Tobacco Lofts (heating dominant)74k ft2 multifamily building in Madison, WI


0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

East CTA Cashman Tobacco Lofts

Energy and

Water Cost ($/ft2)

Conventional HVACGSHP SystemHybrid GSHP System

….for East CTA building

$8,000,000

$9,000,000

$10,000,000

$11,000,000

$12,000,000

GSHP Hybrid Conventional

$8,000,000

$9,000,000

$10,000,000

$11,000,000

$12,000,000

GSHP Hybrid Conventional

Cooling Tower CostGHX CostOther Costs

Ann

ual C

osts

($/ft

2 )


Adjusted Internal Rate of Return

Cashman East CTA Tobacco LoftsHybrid instead of Conventional 10% 12% 9%GSHP instead of hybrid 5% 4% 1%


seventhwave.org/hygchp

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Resources for a deeper lookSeventhwaveDaylight control commissioning| www.seventhwave.org/mndaylightingDemand Control Ventilation | www.seventhwave.org/dcvHybrid Geothermal Controls | www.seventhwave.org/hygchp

CEEEnergy recovery ventilation | www.mncee.org/ervAir source heat pumps | www.mncee.org/heat_pumpsPool facility operations | www.mncee.org/poolAerosol sealing | www.mncee.org/aero

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Your Turn...

Question & Answer

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Series Sneak Peak | July 2017• Characteristics & savings opportunities for residential high energy users• Energy saving opportunities in mobile homes• Home HVAC install and maintenance opportunities• Small embedded data center energy saving strategies• Commercial energy codes support program pilot

Upcoming Deeper Dive Webinars• Roof-top Unit Market Characterization | March 2017• Aerosol Envelope Sealing | spring 2017• Energy Recovery Ventilation Research Results | summer 2017• Commercial Duct Leakage Reduction Opportunities | spring 2017