Impact of Indoor Air Conditions and Solar Radiation on Moisture Accumulation within Multi-Layer Non-Cavity Walls

Abstract

This paper investigates the impact of indoor temperature, humid ity and solar radiation on moisture accumulation within multi-layer non-cavity walls. A transient model [1] that simultaneously considers both thermal and mois ture transient transfer and their interactions in multi-layer non-cavity wall con structions is utilized. Based on the mathematical formulations and the develop ments of the model, a computer simulation program has been developed in order to investigate the impact of the hygrothermal boundary conditions on wall mois ture behavior. By employing the model, both the moisture transport process and the material moisture content within the different layers of a wall system can be evaluated at all possible material moisture conditions. Evaluation of moisture accu mulation within a typical wall system showed that the impact of boundary condi tions is highly dependent on the thermal and moisture characteristics of the wall components. Indoor temperature has been found to have a relatively considerable influence on moisture accumulation in the insulation layer. The presence of solar radiation can lead to considerable reduction in moisture accumulation.