23 September 2011

R-1234yf MIXTURES FOR REPLACING R-407C IN RESIDENTIAL HEAT PUMPS


This paper deals with the design of air-to-water heat pumps dedicated to the
replacement of old oil boilers. Based on the future building regulation to be issued in France
in 2012 for old building refurbishment, the allocation for heating, cooling, lighting, ventilation,
and hot water will be of 80 kWh/m
2
.yr. One of the concerns of the current heat pump
technology using either R-407C or R-410A is the high global warming potential of those
refrigerant blends. The research project presented in this paper aims at defining new
refrigerant blends capable to replace R-407C in those air-to-water heat pumps. The
refrigerant blends, which have been modeled and tested, have GWPs varying between 200
and 600 kg CO2 kg
-1
. Several refrigerants have been simulated using REFPROP 8. One has
been selected and tested on an air-to-water heat pump developed at the laboratory. Energy
performances of this blend are similar to those of R-407C.