Mapping of Air Leakage in Exterior Wall Assemblies

Abstract

A full-scale wood frame test hut with nine wall specimens, typical of low-rise residential construction in the province of Quebec, was built inside an environmental chamber. This test hut was subjected to 66 days of simulated winter and 47 days of late spring climatic conditions to verify the feasibility of different methods of mapping and representing graphically air exfiltration. Through a better understanding of the movement of air through the envelope, the risks related to moisture condensation within the envelope for different wall compositions can be better ascertained. The air leakage pattern characterization methods implemented were two-dimensional grid moisture content monitoring and three-dimensional grid temperature monitoring. The moisture content and temperature data were presented in a graphic form, using isohygrons and isotherms. Temperatures without the impact of air leakage were also calculated using a three-dimensional conductive heat transfer model. The air leakage pattern characterization methods and the resulting moisture and temperature maps are presented and discussed herein.