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ET24SWE0042 - Multipurpose Hydronic CO2 Heat Pump for Commercial Buildings

Project Name
Multipurpose Hydronic CO2 Heat Pump for Commercial Buildings
Project Number
Funding Entity
Market Sector
TPM Category Priority 1
TPM Technology Family Type 1
High-Efficiency Heat Pumps for Space Heating and Cooling
TPM Category Priority 2
TPM Technology Family Type 2
HVAC Design for Decarbonization
TPM Category Priority 3
Water Heating
TPM Technology Family Type 3
Commercial-Duty Water Heaters
Distribution Report
Project Description

The two largest decarbonization targets in a commercial building are typically space heating and domestic hot water. Just these two end-uses account for well over 90% of the natural gas usage in most commercial buildings (excluding food service). Energy efficient, cost-effective solutions for decarbonization of these loads demand emerging technology solutions. There are economic, feasibility, and technological challenges that need to be explored and addressed through the study of early adopters and newly available products.


A newly developed, high-efficiency CO2 heat pump technology can provide space heating, space cooling, and domestic hot water. This new packaged product is commercially available in the U.S.and can produce higher temperature water than previous CO2 heat pumps which can suffice for space heating purposes. This capability enables the low-GWP heat pump to be used for multiple purposes while also replacing existing chillers used for space cooling. This aspect can preempt costly electrical and utility infrastructure upgrades by relying on the same single power service as the existing chiller while simultaneously providing heating and hot water, all with high coefficients of performance. The product is modular, can operate with high return temperatures, and high ambient temperatures – all of which are beneficial in the broadening of CO2 heat pump applications and usability.


This project will explore the design, feasibility, benefits, sizing, and cost of this product as applied to an existing building. The market potential across California will be quantified, including benefits over existing baseline incumbent alternatives. The report will outline the design considerations, how the system would integrate into the building, and provide recommendations and a roadmap for manufacturers, engineers, and utility programs. The design will inform a subsequent field demonstration in a planned follow-up study.