Prediction of hygrothermal environment of buildings based upon combined simulation of heat and moisture transfer and airflow

The hygrothermal environment of the Japanese traditional house constructed by wet process with clay wall and the recent house constructed with industrial building materials are estimated through the interrelated simulation of heat and moisture transfer and airflow using THERB. Thermal theories on conduction, convection, radiation and ventilation of THERB are outlined, particularly algorithm on combined heat and moiture transfer based on thermodynamics. The consequences of this paper highlights that an indoor humidity variation is largely affected by sorption and desorption of walls, the excessive dryness during heating condition can be alleviated by increasing moisture capacity for interior finish material, and THERB has a capability to predict temperature and humidity conditions of buildings.