C08 -- Field Performance and Life Cycle Analysis of Cold Climate Heat Pumps Using Lower GWP Refrigerant

This paper compares the performance of a cold climate air to air heat pump that uses R-410A refrigerant with one that uses the lower global warming potential refrigerant R-454B. The analysis is based on controlled field measured performance of two cold climate heat pump systems tested at the Canadian Centre for Housing Technology located in Ottawa, Canada. It compares the measured capacity and coefficient of performance of these systems under identical load conditions and includes a life cycle analysis of the embodied carbon, upstream and operational emissions associated with the operation of the systems.

The life cycle analysis compares preliminary results of the greenhouse gas emissions associated with cold climate air source heat pumps using today’s conventional R-410A refrigerant, those using the lower global warming potential refrigerant R-454B and highlights the difference between these systems and typical electric and natural gas space heating systems.

Performance results of the cold climate air to air heat pumps showed that the system using R-454B outperformed the system using R-410A.

The life cycle analysis greenhouse gas emissions results showed the high-performance natural gas furnace had the highest life cycle GHG emissions in all scenarios considered, while the R-410A cc-ASHP showed the second highest life cycle GHG emissions. The R-454B cc-ASHP showed the lowest total life cycle GHG emissions. Results showed that embodied emissions become of concern only when all other upstream and operational emissions have been minimized. Fugitive methane emissions associated with the life cycle of natural gas is critically important to the overall life cycle analysis of the systems considered. Shifting load to non-marginal electricity generation (i.e., reducing use of gas-fired power generation) is of paramount importance in reducing life cycle GHG emissions for all-electric heating systems. Refrigerant handling, equipment installation and maintenance practices, which determine refrigerant leakage, are critically important determining factors in evaluating the life cycle emissions of heat pumping systems. This all the more pronounced when considering refrigerant global warming potential at the 20-year time horizon.