CO 2 Refrigerant Heat Pumps Today Janice Peterson, P.E. ACS - - PowerPoint PPT Presentation

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CO 2 Refrigerant Heat Pumps Today Janice Peterson, P.E. ACS - - PowerPoint PPT Presentation

Aug 01, 2023 179 likes •632 views

Emerging Technologies CO 2 Refrigerant Heat Pumps Today Janice Peterson, P.E. ACS Contractor for Bonneville Power Administration Ken Eklund WSU Energy Program Emerging Technologies Showcase August 16, 2017 GoToWebinar Logistics Minimize

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Emerging Technologies

CO2 Refrigerant Heat Pumps Today

Janice Peterson, P.E.

ACS Contractor for Bonneville Power Administration

Ken Eklund

WSU Energy Program

Emerging Technologies Showcase

August 16, 2017

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Emerging Technologies

GoToWebinar Logistics

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questions at any time, or if you have any technical issues NOTE: Today’s presentation is being recorded and will be available at http://e3tnw.org/Webinars

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Emerging Technologies

CO2 Refrigerant Heat Pumps Today

Janice Peterson, P.E.

ACS Contractor for Bonneville Power Administration

Ken Eklund

WSU Energy Program

Emerging Technologies Showcase

August 16, 2017

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SLIDE 4

Emerging Technologies

Need for Research

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  • The 6th power plan called for a 50% penetration
  • f heat pump water heaters (HPWH) by 2030
  • Replacement of electric resistance water

heaters in over 1 million homes

  • 2013 market penetration around 1%
  • The integrated HPWH with synthetic

refrigerants have some limitations:

  • Rated COP of 2.5
  • Single speed
  • High refrigerant Global Warming Potential
  • Need electric resistance back up
  • Remove heat from conditioned space
  • May not fit into existing space
  • Noise
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Emerging Technologies

Game Changing Technology

Split System CO2 Refrigerant Variable Speed Inverter Driven No Electric Element From 50 to 150 F in Single Pass 1.5 kW Input/ 4.5 kW out

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Emerging Technologies

Bonneville Funded Research

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2012 2013 2014 2015 2016 2017 2018

Lab and Field Tests of Domestic Hot Water (DHW) Performance Demand Response Potential Space + DHW in New Homes Retrofit Combined Space + DHW

U.L.

New Applications (Pool heater, multi-family, water source)

* Northwest Energy Efficiency Alliance (NEEA)/BPA Qualified Product List QPL*

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Emerging Technologies

Hurdles to Commercial Success

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  • Familiarity
  • First Cost
  • Finding a contractor
  • HVAC + Plumbing + Electrical
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Emerging Technologies

Addressing the Barriers

Familiarity

Publish Research News stories and other publicity

First Cost

Distributor Buy Down Utility Incentives More Cost Effective Applications

Finding a Contractor

Training/ Installation Guidance Qualified Product List

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Emerging Technologies

What We Will Cover

  • Research on water heating only because it is

necessary to understand combined systems

  • Research on combined space and water

heating systems

  • Lessons learned on the best practice and use
  • f this technology

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Emerging Technologies

Cutting Edge--Not for the Faint Hearted

Requires:

– Ways to import and install non UL listed equipment – Dealing with catastrophic failure – Designing new applications for expanded capabilities which leads to:

  • Engineering new systems
  • Designing monitoring for these systems
  • Developing new concepts for data analysis
  • Learning lessons never imagined at the design phase

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Emerging Technologies

Lab Test Results

  • Linear fit of Energy Factor to

temperature

  • Use Typical Meteorological

Year 3 data to calculate an annual Energy Factor:

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1 2 3 4 5 20 40 60 80 100 Energy Factor Outside Temperature (F)

Performance vs. Outside Temperature

Climate Annual EF Boise 2.9 Kalispell 2.6 Portland 3.0 Seattle 2.9 Spokane 2.8 Outside Air Temperature (F) Energy Factor (EF) COP 17 1.74 2.1 35 2.21 2.75 50 3.11 3.7 67 3.35 4.2 95 4.3 5.0

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Emerging Technologies

Field Monitoring

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Emerging Technologies

HPWH Performance

kWh per 100 gallons water delivered

5 10 15 20 25

kWh/100 gallons

CO2 Split Systems 13

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Emerging Technologies

Demand Reduction Operation

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Blue lines are hot water draws Red blocks are off-peak times when heat pump is allowed to operate

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Emerging Technologies

Impact on Load

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Water Heater Load Shape Total Load Shape

System Off Time in Box—Could Help Flatten the Peaks!

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Emerging Technologies

Impact of Demand Reduction on System Efficiency

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Reduction

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Emerging Technologies

IN EXISTING HOMES

TIP 338

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TIP 326

IN HIGH EFFICIENCY HOMES BPA Funded Research on Combined Systems

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Emerging Technologies

Split System Combi Success!

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  • 10 systems in climates ranging from Northern

California to the Coastal Pacific Northwest provided space and water heat through one to three winters

  • Much was learned regarding

– Equipment design – System design, setup and optimization – Monitoring

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Emerging Technologies

Successful Background

  • Extremely efficient as a dedicated water heater.

Average 7 kWh per 100 gallons=less than 1/3 the energy used by an electric resistance water heater

  • System serves large loads while operating 25% of

time in very cold weather

  • Decided to try adding another load

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Emerging Technologies

Project Design

  • Targeted homes with design heating loads of 10 to 15

thousand Btu per hour—current WA code house design load is 20 to 30 thousand Btu per hour.

  • NEEA provided recruitment, technical assistance to builders,

engineering and monitoring through its Next Step Home program

  • BPA provided program management, building code support,

installation support, lab testing and data analysis and reporting

  • 10 original field sites with 7 located in Heating Climate Zone 1

(≤6,000 Heating Degree Days (HDD)—Coastal), 1 in Zone 2 (6,001 to 7499 HDD—Inland) and 2 in Zone 3 (≥7,500 HDD— Mountain)

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Emerging Technologies

Combi System

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Emerging Technologies

Monitoring and Analysis

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  • Monitoring and analyzing the performance of

two loads from the same source is challenging

  • In the field study there are more than double

the number of sensors in the dedicated water heating research

  • A follow-on lab study was designed to capture

the interaction of the two loads

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Emerging Technologies

Field Energy Factor

Field Energy Factor is a concept created by WSU Energy to represent the total system performance It accounts for heat pump energy plus all system inefficiencies including:

– Tank loss – Pipe loss – Pump energy – Controls – Defrost – Freeze Protection (including heat tape)

The formula is FEF = (QDHW + QSpaceHeat) / QEnergy In

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Emerging Technologies

Performance

Bellingham, WA McCall, ID Olympia, WA Milwaukee, OR Seattle (Ballard), WA Tacoma, WA

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Emerging Technologies

  • Lowest performance correlates with highest return water temperature (5)
  • Performance of Site 5 doubled in Non Heating due to colder supply water
  • Where DHW use drops, performance during Non Heating drops (1 & 7)
  • Largest daily water use correlates with highest FEF due to cold water (10)

20 40 60 80 100 120 1 5 7 10

Heat Return Temperature

Performance Factors

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0.5 1 1.5 2 2.5 3 3.5 4 1 5 7 10

F E F

Site Heat Non Heat

20 40 60 80 100 120 140 160 180 1 5 7 10

G P D

Heat Non Heat

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Emerging Technologies Design Issues—Opportunities for Improvement

  • Defrost issues in cold weather when operating as a

space heater were addressed in new UL listed model

  • Systems worked best where design load was within

heat pump limits—even if load was met by total capacity

  • A system froze during a 10 hour power outage at 20 °F
  • Tank destratification occurred—especially in cold

climates and with high temperature heating systems— which reduced efficiency

  • Cross flow may have contributed to reduced operating

efficiency at some sites

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Emerging Technologies

Defrost Failure

  • Results from supplying

water hotter than 90⁰F to the outdoor unit which tricks the defrost into turning off

  • Designed as a water

heater—not as a space or pool heater

  • Manufacturer immediately

began working to solve the

  • problem. Now has a UL

listed version that defrosts up to 140⁰F supply temp

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Emerging Technologies

Matching Capacity to Load

  • Sites 4 and 6 were both unoccupied but heated during the same period in winter

2015

  • At Site 4, design load is 21,061 Btu per hour—at Site 6 it is 6,226
  • Heat pump capacity for both sites was 13 to 15 thousand Btu per hour depending on
  • utdoor air temperature
  • Site 4 in McCall had sufficient capacity—heat pump plus backup—to meet design

load (-16 °F)

  • During this test period the temperature at McCall plunged from 26 to -8 °F impacting

load

  • Note the large difference in FEF

The very low FEF at Site 4 indicates the system did not function properly The solution is a larger heat pump

Site OAT FEF 4 25 0.13 6 48 2.05

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Emerging Technologies

Tank Destratification

  • Occurs when the heat demand on the tank results in heat supply

flow rates that cycle the storage tank making it all one temperature (at 4 GPM an 80 gallon tank cycles in 20 minutes)

  • Without temperature difference transcritical operation efficiency

plummets

  • To maintain tank stratification:

– Match load to heat pump output – For split systems use a larger tank in combined systems—120 gallon is recommended – Return water to tank location closest to its temperature – Stop circulation when tank reaches bottom of hot water layer and allow heat pump too recover – Like Site 10 use lots of hot water which pulls cold water into the bottom of the tank—maintaining stratification

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Emerging Technologies

Reduce Temperature of Return Water

  • Low temperature systems such as radiant slab

floors work best with hydronic heat pumps

  • Run high temperature return water through a

useful temperature sink such as a preheater for a heat recovery ventilator before returning it to the tank

  • Once again use lots of hot water which pulls

cold water into the system

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Emerging Technologies

Water Supply Sanden Hot Water Storage Tank Sanden Heat Pump

Cross Flow

Tempering Valve Cross Flow

Tempering Valve Highway to Reduced Performance

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Emerging Technologies

Optimized Efficiencies

Using these lessons will help attain the combined system efficiencies predicted in the Ecotope Lab Study of Combined Systems

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Climate Annual Efficiency

Water Heating Space Heating Combined Boise 2.9 2.3 2.5 Kalispell 2.6 2.1 2.2 Portland 3.0 2.6 2.7 Seattle 2.9 2.6 2.7 Spokane 2.8 2.2 2.4

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Emerging Technologies

SPLIT SYSTEM COMBI DR TEST AT PNNL LAB HOMES G3 FIELD TEST CALIFORNIA SITE FIELD TEST DHP + HOT WATER FIELD TEST ECO RUNO LAB & FIELD TEST

TIP 338

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Technology Innovation Projects

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Emerging Technologies

Eco Runo

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Emerging Technologies

System Setup

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Emerging Technologies

  • Cold weather test in McCall, Idaho starting

February 24, 2017

  • Focused on space heating because the water

heater aquastats were not installed until July, 2017

  • The results demonstrate that more research

is needed and why field research is so critical

Two Sites

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Emerging Technologies

Outdoor Air Temperature During Field Test

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Emerging Technologies

Temperatures Inside and Out

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Emerging Technologies

Eco Runo Average Daily Field Energy Factor

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Site One Not Shown

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Emerging Technologies

  • Site 2 is a dream system—the kind of cold

weather heat pump we’ve always wanted

  • Site 1 is a learning opportunity! The results:
  • Are an analysis puzzle
  • May be due to a glitch in our monitoring—but that has

recently been recommissioned

  • May be due to the heat exchange/control unit—the

programming will have to be compared to Site 2’s

  • May have something to do with the set up, control or

function of the heat pump

Welcome to a Brand New Emerging Technology!

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Emerging Technologies

Next Steps

  • Analyze split system combi sites and

monitoring for 2016 and 2017—Courtesy of NEEA

  • Field Test a Ductless Heat Pump plus DHW—

Courtesy of BPA and NEEA

  • Field test the Eco Runo for electric forced air

furnace conversion—Courtesy of NEEA

  • Final BPA TIP 338 report due September 30,

2017

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Emerging Technologies

Conclusion

  • We learn by doing—the lab test never gives us the whole
  • story. Field testing takes us into a much broader field of

variables that must be considered

  • We have a real improvement in water heating technology
  • This same water heater can provide space and water

heating for energy efficient homes in moderate climates—there is much experience that should be followed to optimize performance

  • There is evidence that the Eco Runo may possibly be the

next great emerging technology for cold climates and less efficient homes—if you are a Pacific Northwest utility that wants to join our research please call me

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Emerging Technologies

Contact Information

Ken Eklund, Building Science & Standards Lead Washington State University Energy Program eklundk@energy.wsu.edu Project Principle Investigator and Manager Janice Peterson, Energy Efficiency Engineer ACS Contractor for Bonneville Power Administration jcpeterson@bpa.gov Project Manager

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Emerging Technologies

Next ET Showcase Webinars

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  • RETAC 2.0 & the Regional Technical Forum Aug 30
  • High Efficiency Heat Pump Clothes Dryers

Sept 7

  • Window Attachments

Sept 20

  • Alternative Refrigerants

Sept 28

Join our email list at subscribe-e3tnw@listserv.energy.wsu.edu Webinar information and registration at www.e3tnw.org/webinars

More information about emerging technologies:

  • ET Program: www.bpa.gov/EE/Technology/EE-emerging-technologies/

Thank you for attending!

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Emerging Technologies

Washington State University Energy Program

Your regionally, nationally and internationally recognized energy experts

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