Development of a CO2 Chiller Heat Pump for Multiple North American Applications

Current U.S. heating and cooling applications rely on either synthetic refrigerants or hydrocarbons/fossil fuels, which contribute significantly to climate issues. In addition, electric heaters are commonly used, which consume excessive amounts of electricity. Recently, efforts have emerged to transition away from these traditional methods of heating and cooling and toward the use of heat pumps for heating, cooling, and domestic hot water production. Current heat pump equipment deployed in the U.S. relies on synthetic refrigerants, which pose long-term viability, safety, and societal concerns. In addition, most heating, ventilation, air conditioning and refrigeration (HVAC&R) products are designed and purpose built for a specific application. They are, at best, custom designs that do not allow for manufacturing efficiencies and are often predicated on central plant applications, thus not offering siting efficiency and flexibility. The proposed project pursues a concept that deploys a CO2 refrigerant solution (GWP = 1, no safety or environmental concerns) in a modular concept that enables the delivery of heating, cooling and domestic hot water at 100°C while allowing for the inclusion of manufacturing and application efficiencies (i.e., a modular design vs. a custom design).

Project Impact

Through this program, the project team intends to introduce technologies that can offset the inherent inefficiencies in CO2 cooling systems, including direct vapor injection (DVI) compression, ejectors, pressure exchangers, and novel heat exchanger and system design. Further, CO2 provides excellent heat recovery options and is a very efficient working fluid for heating water. The adoption of systems like this one will eliminate millions of tons of CO2 emissions annually.