Energy Efficiency and Safety for Wall Type Air Conditioner with Propane Refrigerant

Thailand has been used the R-32 refrigerant in air conditioner since 2016, while it has high global warming potentials (GWP = 675). A propane refrigerant (R-290) is introduced as a newly alternative refrigerant, due to the global issue on refrigerant substitution for friendly environment. It has GWP of 4, which is 169 times lower than R-32. In this study, the theoretical energy efficiency was analysed under the Thailand's conditions at the saturated evaporation temperature of 10 degrees C and the saturated condensation temperature of 47 degrees C. However, the propane is highly flammable; therefore, the safety must be considered. The results showed that the coefficient of performance of propane was 5.54, which was 7% higher than R-32. The wall type air conditioner with propane refrigerant would be safe from fire if it was installed at a height higher than 1.8 m above the floor level and the floor area was larger than 17 and 23 m(2) for air conditioner cooling capacity of 3375 W and 5000 W, respectively.