China evaluates the real risks of hydrocarbons

According to JARN, China intends to switch half its production of split air conditioners to propane in order to meet the objectives of the HCFC Phase-Out Management Plan by 2015.This involved identifying potential leakage points and using computational fluid dynamics to study the gas flow within a room and its tendency to concentrate near points of ignition such as electrical switches.
According to JARN, China intends to switch half its production of split air conditioners to propane (R290) in order to meet the objectives of the HCFC Phase-Out Management Plan by 2015. The decision was taken following a comparison of the actual risk factors with the accepted public risk levels, a process known as quantitative risk assessment (QRA).
This involved identifying potential leakage points and using computational fluid dynamics (CFD) to study the gas flow within a room and its tendency to concentrate near points of ignition such as electrical switches. The successive chain of probabilities which could lead to an explosion were as follows: a gas leak entering the room, no diluting air currents, build-up to a flammable concentration (2-10% in the air) and a close source of active ignition.
The results showed that the real risk from R290 ignition events was 0.005 per million per year, far below the “acceptable risk level” of 100 per million per year.
The other main option considered by China for room air conditioners is R32 (difluoromethane).