scholarly journals The Effect of Repeated Moisture Cycles on the Air Tightness of Traditional Clamped Vapour Barrier Joints

2019 ◽  
Vol 24 (1) ◽  
pp. 44-51
Author(s):  
Stig Geving ◽  
Øyvind Norvik ◽  
Lars Gullbrekken
Keyword(s):  
Laboratory Test ◽  
Barrier Layer ◽  
Adhesive Tape ◽  
Air Leakage ◽  
Annual Variations ◽  
Pressure Tests ◽  
Air Tightness ◽  
Wood Frame ◽  
Structural Adhesive ◽  
Center Distance

In this study it has been investigated whether and to what extent, repeated moisture cycles affect the airleakage through clamped overlap joints in the vapour barrier layer. Use of clamped joints is a traditionalway to make airtight joints in the wind- and vapour barrier used in wood frame walls in Norway and othercountries. A laboratory test has been carried out, with a total of 63 pressure tests, being carried out on 9 testsamples, consisting of overlap joints of 0.15 mm polyethylene film clamped between a wooden batten andstud. Each sample was tested seven times after repeated drying and humidification, where the moisturevalues of the sub-cycles were chosen to represent the annual variations of indoor relative humidity.The laboratory test materials were mounted with machine nails with various center spacing (150 mm,300 mm and 450 mm). The overlap joints of the vapour barrier were in the end of the test sealed withadhesive tape, revealing to what extent this over a longer period of time will be beneficial.The results showed that the first moisture cycle (drying) resulted in significant increase of air leakage forall the sample variants. Throughout the moisture cycles, a further strong leakage development for centerspacing 450 mm was observed, which was less for 300 mm, and non-existent for 150 mm. The gain ofusing structural adhesive tape was found to largely depend on the level of perforation resulting from thenails and their center distance. Adhesive tape on the joints resulted in the greatest reduction in leakagenumbers where the center distance between the nails was high, i.e. the reduction was 58% for centerdistance 450 mm. However, with shorter center distance the use of tape only decreased the air leakagebetween 22-39%, revealing the fact that a large part of the joint leakage is through the nail perforations.

scholarly journals Quantifying air leakage through party walls in Toronto semidetached and row-home dwellings

2021 ◽  
Author(s):  
Austin Todd
Keyword(s):  
Air Leakage ◽  
Single Family ◽  
Masonry Construction ◽  
Common Wall ◽  
Air Tightness ◽  
Wood Frame ◽  
Frame Construction ◽  
New Buildings ◽  
Adjacent Unit ◽  
Party Wall

This study contributes to the development of quantifying and understanding building air tightness as it relates to Toronto semi-detached and row homes, particularly party walls. While infiltration characteristics of single family detached homes have been widely developed and understood, the isolation of semi-detached and row home single family dwelling units is relatively unexplored. When quantifying air leakage in a building attached to an adjacent dwelling unit, air is drawn through the exterior envelope as well as the party wall (i.e. shared common wall). The purpose of the proposed testing method, guarded blower door testing, is to isolate air leakage through the party wall from the envelope. Currently the party wall is considered a fire-rated assembly but is not part of the air barrier system. Issues associated with party wall air leakage include spread of fire, indoor air quality, transfer of tobacco smoke between dwellings, and heat loss through the party to attic detail. Data collected on buildings constructed between 1890 and 1920 (Century buildings) has been compared to the data collected on buildings constructed between 2012 to 2017 (new buildings). Air leakage has been collected on twenty-six of Century semi-detached homes with solid masonry construction and twenty-one new semi-detached/row homes of lightweight wood frame construction. Each unit was tested independently and simultaneously, or “guarded”, with the adjacent unit, to pressure neutralize allowing for quantification of envelope and party wall air leakage. Party wall leakage was found to be similar to leakage through the exterior walls. The leakage accounted for 22% of the total infiltration in Century old buildings and 38% in Modern dwellings.

scholarly journals Quantifying air leakage through party walls in Toronto semidetached and row-home dwellings

2021 ◽  
Author(s):  
Austin Todd
Keyword(s):  
Air Leakage ◽  
Single Family ◽  
Masonry Construction ◽  
Common Wall ◽  
Air Tightness ◽  
Wood Frame ◽  
Frame Construction ◽  
New Buildings ◽  
Adjacent Unit ◽  
Party Wall

This study contributes to the development of quantifying and understanding building air tightness as it relates to Toronto semi-detached and row homes, particularly party walls. While infiltration characteristics of single family detached homes have been widely developed and understood, the isolation of semi-detached and row home single family dwelling units is relatively unexplored. When quantifying air leakage in a building attached to an adjacent dwelling unit, air is drawn through the exterior envelope as well as the party wall (i.e. shared common wall). The purpose of the proposed testing method, guarded blower door testing, is to isolate air leakage through the party wall from the envelope. Currently the party wall is considered a fire-rated assembly but is not part of the air barrier system. Issues associated with party wall air leakage include spread of fire, indoor air quality, transfer of tobacco smoke between dwellings, and heat loss through the party to attic detail. Data collected on buildings constructed between 1890 and 1920 (Century buildings) has been compared to the data collected on buildings constructed between 2012 to 2017 (new buildings). Air leakage has been collected on twenty-six of Century semi-detached homes with solid masonry construction and twenty-one new semi-detached/row homes of lightweight wood frame construction. Each unit was tested independently and simultaneously, or “guarded”, with the adjacent unit, to pressure neutralize allowing for quantification of envelope and party wall air leakage. Party wall leakage was found to be similar to leakage through the exterior walls. The leakage accounted for 22% of the total infiltration in Century old buildings and 38% in Modern dwellings.

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 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 Influence of Air-tightness on Heat Energy Performance in Post and Beam Building with Exposed Wood Frame

2012 ◽  
Vol 40 (5) ◽  
pp. 319-326
Author(s):  
Hyun-Bae Kim ◽  
Se-Jong Kim ◽  
Jung-Kwon Oh ◽  
Joo-Saeng Park ◽  
Jun-Jae Lee
Keyword(s):  
Energy Performance ◽  
Heat Energy ◽  
Air Tightness ◽  
Wood Frame

Comparing life cycle implications of building retrofit and replacement options

2005 ◽  
Vol 32 (6) ◽  
pp. 1051-1063 ◽  
Author(s):  
Bonnie Dong ◽  
Christopher Kennedy ◽  
Kim Pressnail
Keyword(s):  
Life Cycle ◽  
Renewable Energy Sources ◽  
Air Leakage ◽  
Detached House ◽  
Basement Walls ◽  
Wood Frame ◽  
Oil Crisis ◽  
Economic Analyses ◽  
The 1960S ◽  
Building Operation

When is it better to retrofit a building as opposed to demolishing and rebuilding it? Life cycle environmental and economic analyses are used to address this question through the study of a typical four bedroom detached house in Toronto. Three vintages of the reference house are used: 1930s solid masonry; 1960s wood frame; and post oil crisis, 1980s wood frame. Retrofit studies considered include insulating the attic and basement walls and air leakage sealing. Over a 40-year life cycle, the rebuild option has lower life cycle energy, global warming potential, and air pollution, which are predominantly associated with building operation. But the retrofit options have lower water pollution, solid waste generation, and weighted resource use, associated with material flows. The retrofit options also have lower life cycle economic costs than rebuilding. In this respect, the preferred options are basement plus air leakage sealing retrofit for the 1930s house, basement retrofit for the 1960s house, and no change for 1980s house. There are ways to overcome the trade-off in negative environmental impacts between retrofitting and rebuilding, such as use of renewable energy sources or re-use and recycling of deconstruction and demolition materials in new construction.Key words: life cycle assessment, life cycle costing, building retrofits, sustainable development.

An Cold Experimental Analysis of Draught System with Chain-Grate Stoker

2011 ◽  
Vol 230-232 ◽  
pp. 1236-1241
Author(s):  
Zhi Ying Zhang ◽  
Jia Hua Lu
Keyword(s):  
Complex Structure ◽  
Air Distribution ◽  
State Testing ◽  
Air Leakage ◽  
High Demand ◽  
Air Supply ◽  
Air Tightness ◽  
The Cost ◽  
Testing And Evaluation ◽  
Machine Work

The study of cold state testing and evaluation analysis were carried on the practical running chain-grate stoker, which has an air-supply system with air storehouse and airtrough, to study the air-distribution, air leakage, air tightness and air governing. The result shows that horizontal air distribution across the furnace and the air tightness of the components such as the air port (damper) and airtrough are good. However the air leakage is large because of the complex structure and the high demand of integrated air tightness either in the front or the back of the stoker. The cost of the stoker is high because of large quantity of machine work after casting and high demand of installation, thus the structure should be improved.

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.

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