Comprehensive correction of thermal conductivity of moist porous building materials with static moisture distribution and moisture transfer

摘要

Accurate determination of the thermal conductivity of building material is key to calculating its heating/cooling loads and energy consumption. The thermal conductivity of building material is not only related to the pore structure characteristics but also the internal static moisture distribution and moisture transfer characteristics, and the mechanisms of both differ in how they affect the internal heat transfer performance. This paper analyzed the influential quantitative relations between the static moisture distribution and moisture transfer with respect to the thermal conductivity of building materials in different hygrothermal environments. The analysis is based on the additional thermal conductivity calculation method derived from static moisture distribution and moisture transfer proposed by us. The results show that the static moisture distribution has a notable influence on the thermal conductivity under the heating conditions in winter, whereas the influence of moisture transfer is negligible. Nonetheless, the influence of both factors on the thermal conductivity should be considered during air-conditioning in summer. The comprehensive correction rate of the thermal conductivity of building materials in typically hot and humid areas in China are determined, and the influence of the thermal conductivity of moist building materials on the heat transfer coefficient of enclosure structures is analyzed. (C) 2019 Published by Elsevier Ltd.