Author : Akshaya Nachankar, Kundlik Mali and Mandar Lele

The hydro-chloro-fluorocarbon (HCFC) and hydro- fluorocarbon (HFC) are common refrigerant used for room air conditioner (RAC). But these are restricted due to a serious environmental issues owing to the high global warming potential (GPW). The replacement with low-GPW refrigerant such as R1234yf, R1234ze, R290 and R32 can be possible. R290 (propane) has major environmental and thermo-physical properties. But it is a flammable substance, thereby posing additional risks. When refrigerant leak into space, it may ignite if the concentration is higher than low flammable limit (LFL), there is always a region where the refrigerant concentration is higher than the LFL because the refrigerant concentration is 100% near the outlet from the air conditioner. Thus, understanding the refrigerant diffusion phenomena of low-GWP refrigerants is important to acquiring sufficient information for developing safety standards to assess the risks of using these refrigerants. In this study, diffusion phenomena were analyzed when a refrigerant leaked slowly from a room air conditioner (RAC) into a closed space.

Keywords: Air conditioner, R290, Flammability.