3D heat and air transport model for predicting the thermal resistance of insulated wall assemblies

摘要

A Wall Energy Rating (WER) system has been proposed to account for simultaneous thermal conduction and air leakage heat losses through a full-scale insulated wall system. Determining WER requires performing two standard tests on a full-scale wall specimen: a thermal resistance test and an air leakage test. A 3D model representation of the wall specimen is developed to combine the results of these tests to obtain an accurate prediction of the wall thermal resistance (apparent R-value) under the influence of air leakage. Two types of wall configurations were tested and simulated. The first one was a standard 2? by 6? wood stud frame construction, made of spruce, spaced at 16? (406 mm) o/c in 2.4 m x 2.4 m full-scale wall specimens. The second wall configuration was similar to the first one except that it included through-wall penetrations. The cavities of the two types of wall configurations were filled with different types of insulation, namely: glass fibre batts and two different types of open cell spray polyurethane foams (light density, 6.8 and 12 kg/m3 nominal), a total of six walls.