The study, carried out by researchers from the Tianjin University of commerce and the Tsinghua Tong Heng planning design and Research Institute, looked at the leak and diffusion of R32 from a 5mm hole in the evaporator while the air conditioner was running. A wall-mounted air conditioner was employed, installed at a height of 2.2m and sized for a room of 31m³.
It found that the combustible zone of R32 only appears near the leak hole, and its duration is very short. Combustion experiments echoed previous tests with R32 that a flame diffuses slightly, but cannot spread effectively.
R32 is being promoted as a lower GWP replacement for R410A in air conditioning systems. It has been designated as an A2L, “mildly flammable”, refrigerant by ASHRAE.
The report can be viewed and downloaded here.
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