Frost damage of roof tiles in relatively warm area in Japan - condensation on external surface

Even in relatively warm area in Japan, frost damage of roof tiles occurs. In this study, the influences of several factors on frost damage are considered from a thermal environmental point of view. Condensation on the external surfaces of roof tiles, which is caused by a temperature drop due to nocturnal radiation, is estimated as one of the most important factors to the frost damage. The frequency of condensation was calculated by a numerical analysis. The influence of the parameters, such as the inclination angle and the orientation of the roof, is investigated. It is clarified that a surface condensation on the roof tiles occurs very frequently even in a warm area of Japan, regardless of the orientation of the roof.