Abstract

This work deals with the evaluation of air flow rate through different building materials used in the construction of building envelope. Experimental measurements of the air flow through and static pressure difference across building walls were carried out. For this purpose a new test configuration consisting of pressurization chambers was designed and developed. In order to validate the new-experimental setup developed, the leakage parameters of some common building materials such as gypsum board and plywood sheathing were evaluated and compared with literature values with satisfactory results. The experimental approach developed in this study was then used to evaluate the air leakage characteristics (resistance, permeance, equivalent leakage area) of brick, impregnated brick and composite walls. Different building envelope configurations were compared in order to assess the airtightness performance and recommend appropriate improvements. This study confirmed that under pressure differentials of 10 to 150 Pa, the air flow regime through rigid building materials is mainly laminar. The research also dealt with the evaluation of the air flow characteristics through a composite system in order to estimate the general envelope performance, by considering the air flow rate through each component layer. The building component airtightness measurements using the proposed experimental configuration were performed under controlled laboratory conditions. This system has the advantage that a large number of rigid specimens can be examined under similar conditions. However, results obtained under laboratory conditions may be significantly different from those of similar components on site evaluation. This is attributed to the effect of workmanship on the airtightness performance of the building envelope