11 December 2024
Annex 54 Country Report: France
This report presents a study carried out by CETIAT on the use of low GWP refrigerant in heat pumps and more specifically on the use of propane as refrigerant.
The progressive phase-out of HFCs and their replacement by natural flammable fluid requires reducing the charge of refrigerant in heat pumps. The objective of this study was to develop a heat pump with the minimum amount of propane possible for an individual 5-kW residential space heating application. An experimental water-to-brine heat pump prototype was built and tested. The unit was designed to be compatible with outdoor air to brine heat exchanger.
The study first focuses on the influence of gas superheating entering the compressor and compressor speed during charge optimisation. It secondly analyses the influence of different evaporator sizes, condenser sizes and compressor technologies on the optimal propane charge. Finally, a seasonal performances analysis is performed on two configurations for which the optimal charges are 190 g and 90 g, respectively.