Characteristics of indoor thermal environment and evaluation method of thermal radiation fields for radiant heating and cooling

This study experimentally investigates the spatial distribution characteristics of indoor thermal environment parameters in different radiant heating and cooling systems, and proposes an evaluation method for thermal radiation fields based on indoor average radiant temperature. The results show that the vertical average radiant temperature difference between floor radiant heating and ceiling radiant cooling systems is approximately 1.5 ℃, while this difference reaches 5.5 ℃ between floor radiant cooling and ceiling radiant heating systems. Meanwhile, the thermal radiation field non-uniformity of floor radiant heating and cooling systems is 2.4%～4.8% and 4.5%～7.7%, respectively, whereas that of ceiling radiant heating and cooling systems is 1.9%～3.5% and 1.0%～2.6%, respectively. Additionally, the thermal radiation efficiency of floor-based systems exceeds 100%, while ceiling-based systems demonstrate the efficiency below 100%. Therefore, significant differences exist in indoor thermal environment characteristics and thermal radiation field performance among various radiant systems, suggesting that system design should consider both thermal comfort and energy efficiency in engineering applications.