Investigating the Influence of Material Properties, Infiltration, and Climatic Conditions on Hygrothermal Risk of Building Envelopes

Abstract

Deterioration of building envelopes due to poor moisture management is considered critical in the sustainability of buildings where wood-frame constructions are widely used. However, the integration of research outputs in building enclosure design analysis considering the combined effects of internal and external parameters is less exhaustively explored. This is partly due to the uniqueness of each component material, the uncertainty of involved factors, and complex interdependencies that influence the response of building envelopes throughout their service lives. To address this issue, hygrothermal simulations and risk assessment of key moisture indicators were performed on wall assemblies exposed to different climatic conditions. The assessment focused on three major issues concerning the moisture design of exterior walls: (1) selection of appropriate materials for optimum performance, (2) effect of moisture infiltration, and (3) different geographic locations. The proposed design methodology includes the simulations and development of a design experiment method based on full-factorial design. The proposed method demonstrates a quantitative appraisal resulting in a clear presentation of moisture accumulation, considering dependencies on various factors. Research findings showed several important factors that affect the hygrothermal performance of wood-frame wall assemblies and need to be considered in the design process. The relationship with the external climate determines the optimal moisture response, given the dependency of the component properties on the drying and wetting potential.