Effect of air leakage on the hygrothermal performance of highly insulated wood frame walls: Comparison of air leakage modelling methods

2017 ◽  
Vol 123 ◽  
pp. 363-377 ◽  
Author(s):  
Lin Wang ◽  
Hua Ge
Keyword(s):  
Air Leakage ◽  
Hygrothermal Performance ◽  
Wood Frame ◽  
Modelling Methods

scholarly journals Highly Insulated Wall Systems with Exterior Insulation of Polyisocyanurate under Different Facer Materials: Material Characterization and Long-Term Hygrothermal Performance Assessment

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3373 ◽  
Author(s):  
Emishaw Iffa ◽  
Fitsum Tariku ◽  
Wendy Ying Simpson
Keyword(s):  
Performance Assessment ◽  
Control Strategy ◽  
Energy Efficient ◽  
Material Characterization ◽  
Air Leakage ◽  
Material Development ◽  
Hygrothermal Performance ◽  
New Construction ◽  
Wood Frame

The application of exterior insulation in both new construction and retrofits is a common practice to enhance the energy efficiency of buildings. In addition to increased thermal performance, the rigid insulation can serve to keep the sheathing board warm and serve as a water-resistive barrier to keep moisture-related problems due to condensation and wind-driven rain. Polyisocyanurate (PIR) rigid boards have a higher thermal resistance in comparison to other commonly used exterior insulation boards. However, because of its perceived lower permeance, its use as exterior insulation is not very common. In this study, the hygrothermal property of PIR boards with different facer types and thicknesses is characterized. The material data obtained through experimental test and extrapolation is used in a long term hygrothermal performance assessment of a wood frame wall with PIR boards as exterior insulation. Results show that PIR with no facer has the smallest accumulated moisture on the sheathing board in comparison to other insulation boards. Walls with a bigger thickness of exterior insulation perform better when no vapor barrier is used. The PIR exterior insulation supports the moisture control strategy well in colder climates in perfect wall scenarios, where there is no air leakage and moisture intrusion. In cases where there is trapped moisture, the sheathing board has a higher moisture content with PIR boards with both aluminum or fiberglass type facers. An innovative facer material development for PIR boards can help efforts targeting improved energy-efficient and durable wall systems.

scholarly journals Hygrothermal performance of highly insulated wood frame walls with air leakage: field measurements and simulations.

2021 ◽  
Author(s):  
Michael J Fox
Keyword(s):  
Simulation Models ◽  
Field Measurements ◽  
Test Facility ◽  
Air Leakage ◽  
Predictive Capacity ◽  
Leakage Field ◽  
Hygrothermal Performance ◽  
Wood Frame ◽  
The University ◽  
Building Engineering

The thesis examines the hygrothermal performance of six types of high thermal resistance (High RSI) wall assemblies during environmental exposure and an air leakage (exfiltration) simulation test. These walls were installed in the Building Engineering Group's test facility (BEG Hut) located at the University of Waterloo. The High-RSI wood-frame walls were assessed by analyzing condensation, mould, and decay risks using the moisture content, temperature, relative humidity and heat flux data collected during the field test. These field-measured data were also used to calibrate one-dimensional WUFI® simulation models for each of the High-RSI assembly for use in future durability assessments using a range of North American climates. Methods were investigated to improve the predictive capacity of these simulation models as well as to increase their utility as a research tool. The design, construction and instrumentation details of the High-RSI study were also documented.

scholarly journals Hygrothermal performance of highly insulated wood frame walls with air leakage: field measurements and simulations.

2021 ◽  
Author(s):  
Michael J Fox
Keyword(s):  
Simulation Models ◽  
Field Measurements ◽  
Test Facility ◽  
Air Leakage ◽  
Predictive Capacity ◽  
Leakage Field ◽  
Hygrothermal Performance ◽  
Wood Frame ◽  
The University ◽  
Building Engineering

The thesis examines the hygrothermal performance of six types of high thermal resistance (High RSI) wall assemblies during environmental exposure and an air leakage (exfiltration) simulation test. These walls were installed in the Building Engineering Group's test facility (BEG Hut) located at the University of Waterloo. The High-RSI wood-frame walls were assessed by analyzing condensation, mould, and decay risks using the moisture content, temperature, relative humidity and heat flux data collected during the field test. These field-measured data were also used to calibrate one-dimensional WUFI® simulation models for each of the High-RSI assembly for use in future durability assessments using a range of North American climates. Methods were investigated to improve the predictive capacity of these simulation models as well as to increase their utility as a research tool. The design, construction and instrumentation details of the High-RSI study were also documented.

Field study of hygrothermal performance of highly insulated wood-frame walls under simulated air leakage

2019 ◽  
Vol 160 ◽  
pp. 106202 ◽  
Author(s):  
Hua Ge ◽  
John Straube ◽  
Lin Wang ◽  
Michael John Fox
Keyword(s):  
Field Study ◽  
Air Leakage ◽  
Hygrothermal Performance ◽  
Wood Frame

scholarly journals Durability of traditional clamped joints in the vapour barrier layer: experimental and numerical analysis

2019 ◽  
Vol 46 (11) ◽  
pp. 996-1000 ◽  
Author(s):  
Lars Gullbrekken ◽  
Klodian Gradeci ◽  
Øyvind Norvik ◽  
Petra Rüther ◽  
Stig Geving
Keyword(s):  
Climate Change ◽  
Energy Consumption ◽  
Climatic Conditions ◽  
The Other ◽  
Use Of Self ◽  
Air Leakage ◽  
Building Envelopes ◽  
Frame Buildings ◽  
Wood Frame ◽  
Numerical Estimations

Clamped joints of wood frame buildings are a traditional way in Norway to attain airtight joints for the air and vapour barrier. There are numerous defects registered in the SINTEF Building Defects Archive related to air leakage through the vapour barrier, on one hand, and stricter requirements for reduced energy consumption, on the other hand, question today’s efficacy of these type of joints. This study investigates the durability of clamped joints by studying how the airtightness is affected by several drying and wetting cycles. Experimental work is carried out to measure air leakage rates, which in turn, are used to evaluate their impact on the airtightness of two different constructions by numerical estimations. Results show that the air leakage rates are increased significantly due to transient climatic conditions. Clamped joints may no longer provide airtight building envelopes given the stricter requirements for energy consumption and implications of climate change. A more promising and robust alternative is the use of self-adhesive tapes.

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

2019 ◽  
Vol 9 (6) ◽  
pp. 1222 ◽  
Author(s):  
Klaus Viljanen ◽  
Xiaoshu Lu
Keyword(s):  
Energy Efficient ◽  
Moisture Transfer ◽  
Mineral Wool ◽  
Rain Event ◽  
Controversial Issues ◽  
Wall Structures ◽  
Hygrothermal Performance ◽  
The Difference ◽  
Wood Frame ◽  
Heat And Moisture

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.

scholarly journals STUDY FOR HYGROTHERMAL PERFORMANCE OF ATTIC IN CONSIDERATION OF AIRTIGHTNESS OF WOOD-FRAME HOUSE BASED ON WHOLE BUILDING HAM ANALYSES

2011 ◽  
Vol 17 (35) ◽  
pp. 221-226 ◽  
Author(s):  
Hiroaki SAITO ◽  
Yoshinori HONMA ◽  
Hisashi MIURA ◽  
Hirotaka SUZUKI
Keyword(s):  
Hygrothermal Performance ◽  
Wood Frame
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