Simultaneous Test of Heat and Moisture Transfer in Aerogel Blankets

Abstract

Thermal insulation is one of the most effective methods to reduce the energy loss through building envelopes because of its low thermal conductivity. However, moisture ingress driven by the pressure gradient across the insulation may lead to a variation of the thermal conductivity, which highly deteriorates the thermal performance of building envelopes and further affects the heating/cooling loads. In this paper, a novel simultaneous test method based on the guarded hot box is proposed to investigate the simultaneous variations of moisture content and effective thermal conductivity of thermal insulation. Two types of aerogel blanket are selected as test specimens. The variations of thermal conductivity versus temperature and moisture are measured and compared. Besides, the variations on the appearance of test samples are also discussed in detail.