Moisture buffering capacity of heavy timber structures directly exposed to an indoor climate: a numerical study

2005 ◽  
Vol 40 (10) ◽  
pp. 1400-1412 ◽  
Author(s):  
Stéphane Hameury
Keyword(s):  
Numerical Study ◽  
Buffering Capacity ◽  
Timber Structures ◽  
Indoor Climate ◽  
Moisture Buffering

scholarly journals Moisture Buffering of Multilayer Internal Wall Assemblies at the Micro Scale: Experimental Study and Numerical Modelling

2019 ◽  
Vol 9 (16) ◽  
pp. 3438 ◽  
Author(s):  
Dobrosława Kaczorek
Keyword(s):  
Penetration Depth ◽  
Buffering Capacity ◽  
Internal Wall ◽  
Simplified Method ◽  
Buffer Value ◽  
Series Of Experiments ◽  
Overall Performance ◽  
Wall Assembly ◽  
Moisture Buffering ◽  
Moisture Buffer Value

In this paper, a series of experiments assessing the moisture buffer value (MBV) of four internal wall assembly samples made from hygroscopic materials was performed. A modified Nordtest protocol was used. Moisture buffer values of all the investigated wall assemblies, with varying moisture loads in the range of 50% to 80%, showed a moderate moisture buffer value (MBV: 0.5–1.0 (g·m−2·%RH−1)). The results showed that in a wall assembly where the MBV of the whole assembly is lower than the MBV of the outer layers, the moisture-buffering capacity of the inner layer is untapped. Outer layers affect inner layers by changing their moisture-buffering capacity, which in turn changes the overall performance of the whole assembly. In addition, it was observed that if the penetration depth value of the outer layer is greater than its thickness, vapour reaches into the deeper layer and wall assemblies made of layers with materials characterized by a lower value of penetration depth reach steady state more slowly. The WUFI Pro tool was used to compare the simulated and experimental results. Despite the discrepancies between these results, it offers a simplified method, helping designers make decisions about which materials to choose to improve the moisture-buffering effect.

Latex Paint Influence on the Oriented Strand Boards and the Indoor Climate

2016 ◽  
Vol 824 ◽  
pp. 226-234
Author(s):  
Tereza Bečkovská ◽  
Lucie Vacková ◽  
Vladimír Tichomirov
Keyword(s):  
Water Vapor ◽  
Indoor Air ◽  
Full Scale ◽  
Timber Structures ◽  
Indoor Climate ◽  
Latex Paint ◽  
The Difference

Oriented strand boards are used to be designed as a water vapor retarder in timber structures. This article presents assessment of latex layer influence on oriented strands boards characteristics. Constructions with latex paint for increasing vapor resistance and constructions with a vapor-proof layer were also compared of indoor air parameters change. The values of hygrothermal properties were monitored in various levels of constructions. Full-scale experiments proved the difference of the humidity phenomena for latex painted boards.

scholarly journals The effect of air velocity on moisture buffering

2019 ◽  
Vol 282 ◽  
pp. 02007 ◽  
Author(s):  
Valeria Cascione ◽  
Eugenio Cavone ◽  
Daniel Maskell ◽  
Andy Shea ◽  
Pete Walker
Keyword(s):  
Air Quality ◽  
Relative Humidity ◽  
Buffering Capacity ◽  
Climatic Chamber ◽  
Air Velocity ◽  
Speed Distribution ◽  
Velocity Correction ◽  
Air Speed ◽  
The Relationship ◽  
Moisture Buffering

Hygoscopic finishing materials improve the indoor hygrothermal comfort and air quality, as they reduce the extremes of variation in relative humidity. This property, known as moisture buffering, is related to the capacity of hygroscopic materials to adsorb and desorb moisture from the air. Air velocity plays an important role on the sorption performances of materials: increasing the air speed leads to increased moisture buffering capacity. In order to obtain comparable results, several moisture buffering protocols require the air speed to be constant and around 0.1 m/s during tests. However, those tests are usually performed in climatic chambers, where air speed cannot be controlled and the flow may not be homogenous. The aim of this study is to demonstrate, that positioning test specimens in different locations within the same chamber gives different moisture buffering value results, due to the non-homogenous air speed distribution. For this reason, air velocity has been monitored, measuring the differential pressure and air speed in different locations in a climatic chamber. Moisture buffering tests have been performed in six locations of the chamber and a correlation between the two analyses has been evaluated. The significance of this paper is to understand the relationship between air speed and moisture buffering performances, in order to determine an air velocity correction factor, which enables the moisture buffering value to be evaluated when existing protocols cannot be adhered.

scholarly journals Towards moisture safe ventilated cold attics – Monitored conditions in a full-scale test building

2020 ◽  
Vol 172 ◽  
pp. 23003
Author(s):  
Thor Hansen ◽  
Eva Møller ◽  
Ruut Peuhkuri
Keyword(s):  
Thermal Resistance ◽  
Buffering Capacity ◽  
Building Envelope ◽  
Full Scale ◽  
Temperate Climate ◽  
Insulation Material ◽  
Full Scale Test ◽  
Hygrothermal Performance ◽  
Scale Test ◽  
Moisture Buffering

Existing building stock in Europe accounts for approx. 40% of the total energy consumption. Upgrading the thermal insulation of the existing buildings is an important measure to reduce heat losses through the building envelope. In some cases, increasing the thermal resistance of the construction may compromise the hygrothermal performance of the retrofitted construction. In particular, if vapour barrier is necessary for the good performance and it is practically difficult, if not even impossible, to install a well-sealed air- and vapour tight layer. To investigate the robustness of the hygrothermal performance of ventilated cold attics – with or without a vapour barrier – a monitoring campaign in a full-scale test building was set up. Also role of number of other parameters like moisture buffering capacity of the insulation material and thermal resistance was investigated. This paper presents part of this measuring campaign, which includes conditions both in the attic space and inside the insulation layer. The monitored data covers a period with two winters. The results show that it in temperate climate is practically indifferent for the hygrothermal performance of the monitored, well-ventilated attics with air-tight ceilings whether there is a vapour barrier or not and if the insulation material has moisture buffering capacity or not.

scholarly journals Impact of Temperature on the Moisture Buffering Performance of Palm and Sunflower Concretes

2021 ◽  
Vol 11 (12) ◽  
pp. 5420
Author(s):  
Fathia Dahir Igue ◽  
Anh Dung Tran Le ◽  
Alexandra Bourdot ◽  
Geoffrey Promis ◽  
Sy Tuan Nguyen ◽  
...  
Keyword(s):  
Numerical Model ◽  
Building Materials ◽  
Numerical Models ◽  
Buffering Capacity ◽  
Physical Models ◽  
Embodied Energy ◽  
Problem Analysis ◽  
Simulation Problem ◽  
Interesting Solution ◽  
Moisture Buffering

The use of bio-based materials (BBM) in buildings is an interesting solution as they are eco-friendly materials and have low embodied energy. This article aims to investigate the hygric performance of two bio-based materials: palm and sunflower concretes. The moisture buffering value (MBV) characterizes the ability of a material or multilayer component to moderate the variation in the indoor relative humidity (RH). In the literature, the moisture buffer values of bio-based concretes were measured at a constant temperature of 23 °C. However, in reality, the indoor temperature of the buildings is variable. The originality of this article is found in studying the influence of the temperature on the moisture buffer performance of BBM. A study at wall scale on its impact on the indoor RH at room level will be carried out. First, the physical models are presented. Second, the numerical models are implemented in the Simulation Problem Analysis and Research Kernel (SPARK) suited to complex problems. Then, the numerical model validated with the experimental results found in the literature is used to investigate the moisture buffering capacity of BBM as a function of the temperature and its application in buildings. The results show that the temperature has a significant impact on the moisture buffering capacity of bio-based building materials and its capacity to dampen indoor RH variation. Using the numerical model presented in this paper can predict and optimize the hygric performance of BBM designed for building application.

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