Heat Pump Water Heaters Kacie Bedney, P.E. – Project Manager Bonneville Power Administration - Energy Efficiency May 24, 2011

Presentation Overview HPWH Potential BPA’s approach to this technology Two projects: Project 1 – Laboratory Testing Project 2 – EPRI Energy Efficiency Demo Lessons Learned Next Steps BPA Resources and Contacts

What is the potential of HPWH? Potential: Only 8 aMW or 31,614 units by end of 2014 Sixth Power Plan potential 5.2 million households in Pacific Northwest 40% 45% of these of these 5% 3.70 million single family homes 1.49 million use electric water heat 673,000 w/ water heater in garage 5% in 5 years

Our approach to this technology….. Project 1: Laboratory Testing* Testing 3 integrated units Project 2: EPRI Demonstration* Nationwide testing of ~160 residential units BPA utilities will install and test 40 units in the region (with an additional 10 “control” homes) HPWHs monitored for: efficiency, performance, reliability, electric demand, application issues and customer behavior *Funded by the Office of Technology Innovation

Which major US HPWH manufacturers? AO Smith 80-gallon Rheem 50-gallon GE 50-gallon

Project 1: Laboratory Testing

BPA laboratory testing Tested 3, US manufactured, integrated units Impact of ambient intake air Impact of exhaust air on home/garage Impact of inlet water temperature Issues about condensation Potential for icing on coils Impact of clogged filter Recovery time Hot water draw profile

BPA lab testing: project goals Gather impact data specific to the region to: “prove” there are conditional impacts and encourage manufacturers to address them, or “disprove” the impacts, allowing installations to commence in the region Evaluate the lab testing results and provide manufacturer-specific feedback to assist BPA in driving Pacific Northwest region-specific technology improvements

BPA lab testing: project team BPA: Project management, methodology oversight, lab test regional coordination, evaluation review, regional rollout of results. Ecotope, Inc. – Develop the analytical methods, protocols and lab testing necessary to evaluate HPWHs and provide technical evaluation reports on the results. Advisory Team – Develop and assist in determining the lab testing criteria. Members include utilities, RTF, contractors, consultants from the region and EPRI. NREL – Lab testing

Testing Chamber at NREL Photo credit: Kate Hudon, NREL PIX # 18678

Testing Chamber at NREL Photo credit: Kate Hudon, NREL PIX # 18667

Our Lab Story: Manufacturer A: 55 degrees

Our Lab Story: Manufacturer B: 55 degrees

Our Lab Story: Manufacturer C: 57 degrees

Lab Testing Observations Manufacturer A: Pro: The component selection and wrap-around condenser implementation provide high levels of efficient heat transfer Pro: Operating range (45F-109F) & compressor performance make this well suited for buffered or semi-conditioned spaces Pro: The larger tank is able to heat water most of the time with the heat pump, without resorting to supplemental resistance elements Pro: Resistance heat will only be used in very high demand applications

Lab Testing Observations Manufacturer A: Pro/con: High air flows across the evaporator do optimize the heat transfer from the air, but come at the expense of fan energy Con: To change the air filter, a screw securing it to the heat pump shroud must be removed vs. a slide out Con: Touch screen is not particularly responsive Con: One mode not offered is simultaneous use of the upper element and the compressor – this would provide maximum heat output while maintaining efficiency

Lab Testing Observations Manufacturer B: Pro: For tanks that don’t mix and remain stratified, the outlet temperature stays high until most of the tank water has been replaced. Pro: Does not enter defrost mode too frequently Pro: Operating modes offer a reasonable mix of strategies to meet efficient or high demand scenarios Con: Changing a set point or the operating mode, which are the most basic adjustments a user would make, requires going through several menus

Lab Testing Observations Manufacturer B: Con: The 45.5 gallon tank is likely to meet the needs of only light to medium hot water use households Con: Compressor does not cycle back to hybrid mode once it has been shut off and the resistance elements take over Con: Not allowing the compressor to turn on again during the recovery cycle is a performance decrement, especially when there are no water draws occurring during that time. Con: Compressor capacity is fairly limited e.g. at 67°F ambient air, a complete draw down (a bath) will take 6-7 hours to heat the tank

Lab Testing Observations Manufacturer C: Pro: The reasonably sized compressor capacity has the advantage of providing more heat, more quickly, to the water in heat pump mode. Pro: Allowing both the compressor & upper element to run is an optimal way to produce hot water quickly while still maintaining improved energy performance Pro/Con: A reasonable mix of strategies to meet efficient or high demand scenarios, but the compressor operating range and the circulation pump limit the usefulness of this

Lab Testing Observations Manufacturer C: Con: Using a temperature gradient on the panel, forces the owner to reference the manual to learn what setting is required for 120°F water Con: The operating range of 60-100°F is too narrow for the Pacific Northwest for garage installations. So it will only work for conditioned spaces.

Lab Testing Observations Manufacturer C: Con: For temperatures below the low 60s, the coil temperature drops quickly to a range which could induce frost buildup. The compressor cycles off for a defrosting period. But with no active defrosting, the equipment uses resistance heat while waiting for the coils to warm up again Con: In using a circulation pump in the design of the equipment, extremely low water users may find the water temperatures acceptable, but other users are likely to encounter undesirable periods of cold water.

Project 2: EPRI Energy Efficiency Demonstration

EPRI Energy Efficiency Demonstration Nationwide testing of 160+ residential HPWHs GE, AO Smith, Rheem Collaborative research with multiple utilities BPA utilities will test 40 units in the region (with an additional 10 control homes) HPWHs monitored for: efficiency, performance, reliability, electric demand, application issues and customer behavior

EPRI Energy Efficiency Demonstration 40 treatment sites Single-family residential homes, maximum 10 per utility Provided with new HPWH Instrumented and monitored for up to 2 years Daily uploads of data to EPRI via internet Occupant observations before and after installation Occupants permitted to adjust water temperature and operating modes as desired Occupants instructed to operate HPWH normally, year-round

EPRI Energy Efficiency Demonstration 10 control sites Single-family residential homes, maximum 3 per utility Instrumented and monitored for up to 2 years Provides baseline for comparison with treatment sites

Monthly COP vs. Ambient Temp for BPA January 2011

Monthly COP vs. Ambient Temp for BPA February 2011

Monthly COP vs. Ambient Temp for BPA March 2011

Monthly COP vs. Ambient Temp for All March 2011

Customer Feedback (~1 month) Temperature Change around Water Heater 24 of 40 (60%) noticed it was colder around the unit Majority didn’t find it bothersome, a minor annoyance at best Noise 37 of 40 (93%) noticed the additional noise 7 answered “bothersome”, but considered it a mild disturbance Features and Controls Installers generally provided little training and many didn’t understand how HPWHs operate Homeowners found the features/controls easy to understand and use Most adjusted their water temperature (default is 120-deg F)

Noise Perspective Noise Pollution Clearinghouse* 30 Installed Sites Refrigerator 40-43 Typical Living Room 40 Forced Air Heating System 42-52 Radio Playing in Background 45-50 Exhaust Fan 54-55 Microwave 55-59 Normal Conversation 55-65 Clothes Dryer 56-58 Window Fan on High 60-66 Dishwasher 63-66 Clothes Washer 65-70 Hair Dryer 80-95 30 Installed Sites HPWH Intake 55-64 HPWH Exhaust 55-67 (readings taken 3-ft from unit, 5-ft from floor) * http://www.nonoise.org/library/household/index.htm

Installation Lessons Learned Water pressure should be recorded as a part of the site assessment and a regulator installed if the pressure does not meet the following parameters: Manufacturer Water pressure cut off Protocol Install regulator to: GE 80 psi Maintain pressure below 80 psi AO Smith Maintain pressure below 50 – 60 psi Rheem 125 psi Maintain pressure below 125 psi Daikin Capacity of pressure relief value Maintain pressure within capability of relief value

Installation Lessons Learned Category Lesson HPWH STAND Consideration should be given to local codes, as some jurisdictions may require stands for electric water heaters installed in garages based on fire concerns with a potential ignition source. HEAT TAPE Heat tape is not necessary for condensate drains located in garages in the NW. EXPANSION TANK If not present, an expansion tank must be installed to meet code requirement for thermal expansion.

Installation Lessons Learned Category Lesson CONDENSATE LINES Consideration should be given to the necessity of condensate lines or a condensate pump for each installation. DAIKIN ALTHERMA INSTALL Installation of the Daikin units is considerably more complex than the tank-integrated HPWH units. At a minimum, this is a 2 day installation which requires detailed commissioning per unit/location according to the Daikin’s field settings report and an additional visit at 4 – 6 weeks to check and clear the closed water loop strainer.

Next Steps for BPA Combine: Determine: Laboratory test data (controlled environment data) Early EPRI demonstration NW results (“real life” data) Determine: What are the energy savings from this technology? What is the cost benefit? Determine the readiness of a BPA incentive Can BPA support this current technology?

BPA Resources Check out BPA’s Web site for more information about HPWHs and other residential activities http://www.bpa.gov/energy/n/residential.cfm Link to BPA’s laboratory testing protocols http://www.bpa.gov/energy/n/emerging_technology/pdf/HPWH_MV_Plan_Final_012610.pdf Link to BPA’s Emerging Technology activities http://www.bpa.gov/energy/n/emerging_technology/projects.cfm

Contact Information BPA Lab testing, Field testing Kacie Bedney, HPWH Project Manager Bonneville Power Administration 503.230.4631 kcbedney@bpa.gov BPA Emerging Technology Jack Callahan, Emerging Technology 503.230.4496 jmcallahan@bpa.gov BPA Residential Sector, general Sarah F. Moore, Residential Lead Bonneville Power Administration 503.230.4157 sfmoore@bpa.gov