Indoor leakage test for safety of R-290 split type room air conditioner

• A simulated leak from a cylinder is compared to a leak from a running system.
• The leaked R290 concentrations are measured and analyzed.
• The room cannot reach combustible except the directly underneath of the leaking.

The selection of alternative refrigerants for the room air conditioner (RAC) industry has, in recent years, been a significant challenge. According to the literature, flammable refrigerants may be one of the potential options. In particular, R-290 (propane) has a major possibility to be the chosen working fluid for the next generation of RACs because of its environmental and unique thermo-physical properties. However, its use is hindered by its flammability and the resulting concerns on safety. In this paper, the safety implications of using R-290 are examined through evaluating the effects of certain variables upon the concentrations of leaked refrigerant into a room. R-290 is leaked under different scenarios and its distributions inside room are measured. The results are interpreted with respect to the requirements of RAC safety standards, where it is found that the requirements may need more detailed verifying for wall type RAC.