Calculation methods of indoor mean radiant temperature of floor radiant cooling system and effect of surface emissivity

Using theoretical and experimental analysis methods, focuses on the impacts of surface materials’ emissivity on indoor mean radiant temperature of floor radiant cooling system, and compares calculation methods of mean radiant temperature.The results show that the internal wall surface material with lower emissivity has higher surface temperature to reduce heat transfer through walls. For the mean radiant temperature calculation, when the indoor surface emissivity changes, recommends the definition calculation method or the simulation simplification method. The traditional simplification method is no longer applicable. When using low emissivity materials in roof and side walls, the mean radiant temperature can be reduced by about 4 ℃.