Operative temperature

In recent years, the adoption of water-based radiant ceiling cooling systems has been increasing in Japan with the aim of realizing comfort and energy savings. Conventionally, when designing radiant cooling systems, the target operative temperature for the indoor thermal environment is set, but these are usually combined with convection air conditioning system, which do not always achieve the target value during summer cooling.

According to the Czech legislative act the operative temperature is the evaluation criterion for thermal comfort in air-conditioned or heated spaces. The operative temperature respects the air temperature; mean radiant temperature and air velocity. For mean radiant temperature calculation the surface temperature of the surrounding walls must be known. Manual calculation of the mean radiant temperature is very complicated and not suitable for practical usage since the surface temperatures are difficult to determine.