Thermal and moisture monitoring of an internally insulated historic brick wall
Thermal and moisture monitoring of an internally insulated historic brick wall
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DOI：
10.1016/j.buildenv.2018.02.020
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发表时间：
2018-04
影响因子：
7.4
通讯作者：
R. Walker;S. Pavia
中科院分区：
文献类型：
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作者：
R. Walker;S. Pavia
内保温墙体是建筑节能改造的一种有效方法。然而，隔热材料改变了墙壁的潮湿特性，并可能增加墙壁因水分积聚而腐烂的风险。本文通过在抹灰层与砖墙界面附近放置探头，研究了砖墙内保温材料在两年半时间内的热湿性能，其现场性能与实验室测定的热湿性能一致。这是一致证明，蒸汽渗透性的绝缘有很大的影响，对墙壁的水分。具有可渗透蒸汽的隔热材料的墙壁紧密地反映了室内相对湿度（RH）条件，并在反映室内RH变化方面表现出最大的响应和最短的滞后时间。相反，具有低蒸汽渗透性隔热材料的墙壁显示出较低的RH波动和较长的滞后期，因为水分运动受到阻碍。有一个减少在墙壁的相对湿度的所有绝缘房间加热时，与蒸汽可渗透的绝缘显示最大的减少相对湿度由于墙壁水分干燥和提高壁温，而较少的蒸汽可渗透的绝缘降低相对湿度主要是由于壁温上升的墙壁应用。结果表明，蒸汽渗透绝缘适用于潮湿环境，低相对湿度的时期，为墙壁提供了干燥的机会。隔热材料的热性能必须与防潮性能和建筑物的长期耐久性相平衡。
Internally insulating walls is an effective method of energy retrofitting buildings. However insulation changes the hygric behaviour of a wall and can increase the risk of wall decay by moisture accumulation. This paper investigates thermal and moisture behaviour of internal insulations applied to a brick wall over a two and a half year period with probes positioned near the interface between the leveling plaster and brick wall.The in-situ performance of the insulations agrees with their laboratory measured thermal and moisture properties. It is consistently evidenced that the vapour permeability of the insulation has a large impact on the wall moisture. Walls with vapour permeable insulations closely reflect internal room relative humidity (RH) conditions and show the greatest response and the shortest lag time in reflecting changes in room RH. Conversely, the walls with low vapour permeable insulations display lower RH fluctuations and longer lag periods as moisture movement is impeded. There is a reduction in the wall's RH for all insulations when room heating is applied with the walls with vapour permeable insulations showing the largest reduction in RH due to wall moisture drying and raising wall temperatures while the less vapour permeable insulation lowered RH mostly on account of rising wall temperatures. The results suggest that vapour permeable insulations are suitable in moisture environments with periods of low RH that provide the wall with an opportunity to dry. The thermal performance of an insulation must be counterbalanced against moisture performance and the resultant longterm durability of the building.