Comparing lower GWP (Global Warming Potential) alternatives for a 10 kW R-410A Heat pump, a study carried on by the IIR (International Institute of Refrigeration) Working Group on LCCP (Life Cycle Climate Performance) Evaluation concluded that blends of HFC-32 with HFOs (GWP around 500) had a lower LCCP than HFC-32 or propane R-290.
Energy consumption was calculated using the AHRTI LCCP tool with the performance information from Alternative Refrigerants
Evaluation Program (AREP) Report #22, and average leakage rates were from UNEP Technical Options Committee 2002 report and ICCP Fourth assessment report (2007). It was noted that leakage rates have dropped over the last decade and continue to drop, and that the values used should be updated as new information becomes available.
The two refrigerant blends contained around 72 % HFC-32 and HFO-1234yf or HFO-1234zeE.
In case of the lower GWP alternatives, total lifetime GHG (Greenhouse Gases) emissions due to energy consumption represented from 95.5 % to 98.7% of total emissions. The authors noted that, for this reason, the most effective way to reduce emissions is to increase the energy efficiency of the unit.