An Experimental Study on the Drying-Out Ability of Highly Insulated Wall Structures with Built-In Moisture and Rain Leakage

Abstract

The recent research on highly insulated structures presents controversial conclusions on risks in moisture safety. This paper addresses these controversial issues through investigating the hygrothermal performance of energy efficient envelope structures under high moisture loads. The experiments consist of built-in moisture and rain leakage tests in mineral wool insulated structures. A heat and moisture transfer simulation model is developed to examine the drying-out ability in both warm and cold seasons. The results show that the energy efficient structures have an excellent drying out ability against built-in and leakage moisture. The difference in the drying ability is limited compared to conventional structures. A critical leakage moisture amount reaching the insulation cavity for a wood frame wall is determined to be between 6.9–20.7 g in a single rain event occurring every other day. Further research is required to target highly insulated structures, particularly addressing water vapor diffusion and convection.

Hygrothermal Behaviour of Ventilation Cavities in Highly Insulated Envelopes

“…The research on the hygrothermal behavior and moisture safety of the highly insulated (HI) structures has focused mainly on the insulation space of the structures [1][2][3][4][5][6][7]. Due to the influence of the temperature distribution across the external structure on the hygric behavior, the performance is usually evaluated at the colder outer parts of the structure, excluding the ventilation cavity from the analysis [1][2][3][4][5][6][7]. The drying ability of the built-in moisture has been addressed by [1][2][3][4][5] and the effect of climate change by [2,5].…”

“…Due to the influence of the temperature distribution across the external structure on the hygric behavior, the performance is usually evaluated at the colder outer parts of the structure, excluding the ventilation cavity from the analysis [1][2][3][4][5][6][7]. The drying ability of the built-in moisture has been addressed by [1][2][3][4][5] and the effect of climate change by [2,5]. Only one of these studies is mainly based on experimental research methods [4].…”

“…The drying ability of the built-in moisture has been addressed by [1][2][3][4][5] and the effect of climate change by [2,5]. Only one of these studies is mainly based on experimental research methods [4].…”

Zero Energy Buildings: A Reached Target or a Starting Point?

“…So, everything has been said on that topic? Not at all, and up-to-date research on all aspects related to the design of a zero-energy building is still being developed, as the articles reported [1][2][3][4][5][6][7][8][9][10][11] in this special issue testify.…”

“…In fact, the reader will find in the following papers, some works at the level of the component-such as the one of Memon et al [2] that studies the performance of a triple vacuum glazing, the one of Viljanen and Lu [6] on the moisture performance of highly insulated walls, the one of Dong et al [5] on the energy savings potential of cross-laminated timber constructions, and the study of passive solar systems by Cui et al [11]-and the others at the level of the building. Two works (Ruiz et al [3] and Ferrara et al [8]) treat the problem of the integration of renewable sources within a ZEB.…”