Effect of solar radiation on human thermal comfort in a tropical climate

The contribution of solar radiation on the global thermal comfort and local thermal comfort condition for a person sitting near a glass window in a building located in a tropical climate was studied. The effects of transmitted direct solar radiation, transmitted diffuse solar radiation, inside glass surface temperature and distance of a seated person from the glass window on the predicted percentage of dissatisfied (PPD) and plane radiant temperature asymmetry (RTA) were studied. PPD and RTA due to transmitted diffuse solar radiation and high inside glass surface temperature were decreased with the distance from the glass window. PPD was decreased exponentially with the distance from the glass window, while RTA was decreased slowly with the distance from the glass window. The findings show that PPD and RTA due to transmitted direct solar radiation striking the human body are not dependent on the distance from the glass window, but they are dependent on the magnitude and direction of the solar beam radiation incident on a human body. The results of the study would help the building designers to be able to design the interior working space for the tenant sitting near the glass window to achieve the acceptable level of thermal comfort condition.