Evaluation of the performance of radiant ceiling cooling system from the perspective of thermal comfort, considering human presence and non-uniformity of the ceiling surface temperature

Document Type : Original Article

Authors

Amin Haghighi Poshtiri

Mohammad Alipour Dehsari

Associate Professor, Faculty of Mechanical Engineering, University of Guilan, Rasht.

10.22067/jacsm.2025.92064.1315

Abstract

In this study, the thermal comfort in a room equipped with a ceiling cooling system and considering the presence of humans were numerically analyzed to investigate the effect of ceiling temperature changes. k-ε models, discrete coordinates, and raytracing were used to simulate air flow, solar radiation, and radiation, and thermal comfort was evaluated with the Fanger model. Application of ceiling temperature difference of 1C, 3C and 5C caused violation of thermal comfort. By applying the ceiling temperature difference with an average equal to the constant temperature ceiling condition, thermal comfort improved and PMV value was 0.52, 0.55 and 0.59, respectively. Investigating the effect of ceiling temperature difference on thermal comfort in 9 different areas of the room also showed that at temperature difference of 1C for the ceiling, only the central area is out of thermal comfort conditions. At temperature difference of 3C, the number of areas outside of thermal comfort increased to two areas, and at the temperature difference of 5C, this number reached three areas.

Keywords

Roof cooling

numerical analysis

thermal comfort

human presence

roof surface temperature changes

Subjects

• Heat transfer

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