Air Intrusion and Its Impact on Energy Performance of Roofing Assemblies

摘要

Air intrusion into roof assembly is a concern for wind uplift resistance and life cycle performance of roofs.Currently,there are no widely accepted standard specifications or test methods to determine air intrusion into roof assemblies.Towards this objective,an experimental procedure has been under development at the National Research Council of Canada.As part of this investigation,five roofing assembly configurations were quantified for air intrusion.Relative performance of the air retarding effect of the five assemblies indicated that assemblies with air barrier/retarder had lower air intrusion rates than without.Measured air intrusion rates are compared with the existing codes of practice and standards.This comparison clearly demonstrates the significance of air intrusion into the roofing assembly and the necessity of a standardized air intrusion test method for the roofing industry.With the measured data,attempts were made to perform energy load calculations using a simplified procedure,and through two case studies the impact of air intrusion on energy performance of roof assembly was estimated.