PROSPECTIVE OF HFC-161 AS AN ALTERNATIVE TO HCFC-22 IN AIR CONDITIONERS

Widely used HCFC-22 in air conditioning and heat pump applications has to be phased out in near future. Most potential alternatives are HFC-410A and HC-290. While R-410A has the issue of high GWP, HC-290 has the flammability. HFC-161(Fluroethane) has zero ODP and ultra low GWP. The thermophysical properties of HFC-161 are very close to HCFC-22 except flammability. The lower flammability limit of HFC-161 is 3.8% by volume in air, which is almost double of HC-290. It is reported that it has good compatibility with mineral oil. HFC-161 has not yet been classified by ASHRAE Standard 34 for safety. This paper discusses the simulated results on the suitability of HFC-161as an alternative to HCFC-22 for room air conditioning applications. The simulation has been done using IMST ART for drop-in conditions as well as for some design variations including compressor capacity and condenser area. The results show that the cooling capacities are comparable with HCFC-22 and HC-290. COP is higher than both HCFC-22 and HC-290. The discharge temperatures are lower than HCFC-22 but higher than HC-290. EN 378 specifies the allowable charge in a closed space to avoid any risk due to flammability. While the limit is about 8g/m(3) for HC-290, it is about 15 g/m(3) for HFC-161. For an air conditioner with a cooling capacity of 5.27 kW, one has to take special efforts to meet this limit for HC-290. However, it may be possible for HFC-161 to meet EN 378 without many changes in the heat exchanger configurations.