Several approaches can be taken in studying the combined heat and moisture transport characteristics of building materials. The "effective moisture penetration depth" (EMPD) approach described in this paper is a simplified method of analysing moisture transport in buildings and is easy to incorporate into existing building energy analysis computer codes. First, the paper introduces the building domains and explains the lumped heat and moisture balance equations for the room air. The components of the moisture balance equation involving moisture adsorption and desorption are described in detail where the concept of EMPD is discussed. The assumptions. parameters required, and limitations of the model are also discussed. Results of simulation using the model and comparison with measured data are given. Data of isotherms compiled from the literature of some commonly used building materials are also given.

KEYWORDS: calculating, heat flow, climate, air conditioning, moisture, data, dehumidifying, comparing, measuring.