Influence of Moisture on the Energy Performance of Retrofitted Walls - Experimental Assessment and Validation of an Hygrothermal Model

Abstract

ABSTRACT The rehabilitation of existing buildings façades should be based on the improvement in comfort and the decrease of energy consumption. For this purpose, it is necessary to select a retrofitted solution capable of minimizing the heat losses across the building envelope. However, it is not only the retrofitted solution of the wall that influences the amount of heat transported across it, but also the moisture content in the wall under in-service conditions. An experimental prototype was developed to experimentally assess the impact of a wetting period on the energy performance of wall test specimens. The experiment simulated the exposure of the specimens to a rainy period with a continuous record of the heat fluxes across both surfaces of the specimens. Additionally, the validation of the WUFI hygrothermal simulation model, based on the experimental measurements performed, was carried out. Driving rain resulted in an increase of heat losses of around 10%.