Affordable Near- and Medium-Term Solutions for Integration of Low GWP Heat Pumps in Residential Buildings
Develop and Demonstrate next generation heat pumps utilizing low global warming potential refrigerant, achieve high efficiency, and achieve cost savings.
The project is in the process of retrofitting the ten demonstration sites with the near-term heat pump solution using a lower-cost compressor drive coupled with the low-GWP refrigerant R-454B. The existing systems were monitored for one year to establish a baseline energy usage for each home. The medium-term solution is focused on improving the performance of air-to-water heat pumps with the potential to safely incorporating ultra-low, natural refrigerants. This project is evaluating advanced microchannel polymer heat exchanger designs to improve heat exchanger performance relative to typical fin-tube type heat exchangers used in hydronic systems. The project team is evaluating manufacturing methods for developing the polymer heat exchanger such as injection molding and 3D printing. A small scale heat exchanger has been completed with both manufacturing methods and currently being tested for mechanical and thermal performance. This heat exchanger will be coupled with an air-to-water heat pump and tested in a laboratory setting.
This project develops and demonstrates affordable near-term (TRL 4- high 7) and medium-term (TRL 4- low 7) solutions for integration of lower cost, low- and ultra-low global warming potential (GWP) heat pumps. The combination of addressing both near-term (GWP < 750) and medium-term (ultra-low GWP <10) needs is necessary to meet California's carbon reduction goals. The near-term solution focuses on a closer-to-market emerging technology that uses a proprietary, a lower cost compressor drive. This technology will be demonstrated for cost and energy savings at 10 pilot sites. The goal is to provide a market-ready product that is more efficient and 10% lower cost. The medium-term solution incorporates an innovative heat exchanger in the secondary loop to improve its efficiency, enabling use of hermetically-sealed ultra-low GWP flammable refrigerants in heat pumps. This technology will be tested at a laboratory scale.
Reducing the cost of heat pumps will make them more attractive to customers who have so far largely ignored them due to high upfront costs relative to alternatives.
The proposed research will lead to lower costs for heat pumps in the near- and medium-term. This is necessary for greater market uptake.
A total of 9.2 Million therms of natural gas could be offset through increased use of electric heat pumps, and while this would increase the electric demand statewide by 63.7 GWh, the greenhouse gas emissions in California relate.
Key Project Members
TRC Engineers, Inc.
Merced County Community Action Agency
Southern California Edison
Regents of the University of California, Davis
Dr. Prath Vaishnav