Comparison of R-407C AND R-410A with R-22 in a 10

The performance of two long term replacements R-407C (HFC-32/125/134a (23%/25%/52%)) and R-410A (HFC-32/125 (50%/50%)) was compared to R-22 in a 10.5 kW (3.0 TR) residential central heat pump. The performance evaluations were carried out in a psychrometric calorimeter test facility located at NRC using the Canadian Standards Association (GSA) I Air-Conditioning and Refrigeration Institute (ARI) rating conditions. The performance of R-407C was measured with the same reciprocating compressor that was supplied with the R-22 system. However, the performance evaluation of R-41 OA required a change to an appropriately sized scroll compressor in order to provide a comparison at approximately the same cooling capacity. Performance characteristics were measured including compressor power, cooling and heating capacity, refrigerant mass flow. and cooling energy efficiency ratio (EER) and heating coefficient of performance (COP). To identify areas where the energy efficiency could be improved the heat pump evaporator was also partially optimized to suit the characteristics of R-407C. The optimization included changing the direction of the air flow (inverting the evaporator coil) to get an approximation of a counterflow heat exchanger to take advantage of R-407C's temperature glide.