The Experts below are selected from a list of 12390 Experts worldwide ranked by ideXlab platform
Thoroskar Relander - One of the best experts on this subject based on the ideXlab platform.
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Airtightness estimation a state of the art review and an en route upper limit evaluation principle to increase the chances that wood frame houses with a vapour and wind barrier comply with the Airtightness requirements
Energy and Buildings, 2012Co-Authors: Thoroskar Relander, Sverre Holos, Jan Vincent ThueAbstract:Abstract High Airtightness is particularly important in order to achieve energy efficient buildings. Of this reason Airtightness estimation is of interest. Over the past 30 years researchers have worked on Airtightness estimation. This article is divided into two parts. The 1st part deals with earlier work on Airtightness estimation. It is seen that there are relatively few references in the literature that deal with estimation of Airtightness. None of the reviewed references argue that Airtightness measurements can be replaced by estimates. The only reference that deals with Airtightness estimation of wood-frame houses with high Airtightness did not manage to find a correlation between the estimated and the measured Airtightness. For a contractor what really matters is not an estimate of the Airtightness of the finished building, but a reliable means to be sure of reaching the Airtightness requirement. It is therefore customary to perform blower-door tests stepwise during the construction process. First the Airtightness of the building with the wind-barrier is measured, n 50w . Then the Airtightness of the finished building that also has a vapour barrier is measured, n 50f . The Airtightness requirement is set for n 50f . Of various reasons it is not given that n 50f n 50w for a given building, and consequently one should have an idea of what an upper limit of n 50w should be in order to be confident to reach the n 50f requirement. In the 2nd part of the article it will be shown how this upper limit of n 50w can be found by statistical analysis based on systematic measurements of n 50w and n 50f as part of a quality assurance system.
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Airtightness estimation—A state of the art review and an en route upper limit evaluation principle to increase the chances that wood-frame houses with a vapour- and wind-barrier comply with the Airtightness requirements
Energy and Buildings, 2012Co-Authors: Thoroskar Relander, Sverre Holos, Jan Vincent ThueAbstract:Abstract High Airtightness is particularly important in order to achieve energy efficient buildings. Of this reason Airtightness estimation is of interest. Over the past 30 years researchers have worked on Airtightness estimation. This article is divided into two parts. The 1st part deals with earlier work on Airtightness estimation. It is seen that there are relatively few references in the literature that deal with estimation of Airtightness. None of the reviewed references argue that Airtightness measurements can be replaced by estimates. The only reference that deals with Airtightness estimation of wood-frame houses with high Airtightness did not manage to find a correlation between the estimated and the measured Airtightness. For a contractor what really matters is not an estimate of the Airtightness of the finished building, but a reliable means to be sure of reaching the Airtightness requirement. It is therefore customary to perform blower-door tests stepwise during the construction process. First the Airtightness of the building with the wind-barrier is measured, n 50w . Then the Airtightness of the finished building that also has a vapour barrier is measured, n 50f . The Airtightness requirement is set for n 50f . Of various reasons it is not given that n 50f n 50w for a given building, and consequently one should have an idea of what an upper limit of n 50w should be in order to be confident to reach the n 50f requirement. In the 2nd part of the article it will be shown how this upper limit of n 50w can be found by statistical analysis based on systematic measurements of n 50w and n 50f as part of a quality assurance system.
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the influence of the joint between the basement wall and the wood frame wall on the Airtightness of wood frame houses
Energy and Buildings, 2011Co-Authors: Thoroskar Relander, Bjørnar Heiskel, John TyssedalAbstract:Abstract An airtight building envelope is crucial to achieve energy efficient buildings. The Norwegian Airtightness requirements have become stricter, leading to an increased interest in methods for ensuring airtight building envelopes. The joint between the basement wall and the wood-frame wall is known to be a typical air leakage path. Using laboratory measurements and a statistical experimental design the influence of the 3 factors flatness of the basement wall, the sealing method used in the joint and the load between the wood-frame wall and the basement wall is investigated. The influence of this air leakage on real wood-frame houses is also estimated. The results show that the flatness of the basement wall top surface has a considerable influence on the air leakage, a flatter surface generally leading to less air leakage. The sealing materials have widely differing Airtightness properties. The least airtight sealing materials, which also are the non-malleable ones, turn out to be sensitive to the flatness of the basement wall and the load on the wall. The estimates of the influence of the air leakage on real wood-frame houses show that the least flat surfaces should be avoided for the non-malleable sealing materials. It is also seen that if the least favourable sealing method is used, or if the sealing is forgotten, the influence on the total Airtightness can be remarkable. However, the results also show that it is possible to make the influence of the joint on the total Airtightness negligible.
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the influence of structural floors on the Airtightness of wood frame houses
Energy and Buildings, 2011Co-Authors: Thoroskar Relander, Staf Roels, Jan Vincent Thue, Geert Bauwens, Sivert UvslokkAbstract:Energy use in buildings has come more into focus in recent years. An airtight building envelope with a low infiltration is a definite prerequisite to achieve an energy efficient building. Recently the Norwegian Airtightness requirements have become stricter. This leads to an increased focus on airtight constructions and methods. Platform constructed structural floors are widely used in Norway. Air leakages are frequently observed in connection with structural floors, both at the wall/floor and wall/ceiling junction and as leakages into the floor or into the ceiling. This article discusses the importance of the leakages in platform constructed structural floors on the Airtightness of wood-frame houses. This is done by laboratory measurements of vapour barriers and wind-barriers mounted on a wall with structural floor beams. The results show that the Airtightness performance of the vapour barrier can be made almost as good as the wind-barrier. However, this is quite labour-intensive. With a properly mounted wind-barrier, the influence of the structural floors on the Airtightness of a wood-frame house can be made negligible.
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Airtightness of wood ‐ frame houses
2011Co-Authors: Thoroskar RelanderAbstract:There are many reasons to focus on Airtightness. High Airtightness is particularly important to achieve energy efficient buildings. High Airtightness is also advisable to reduce the risk of moistur ...
Jan Vincent Thue - One of the best experts on this subject based on the ideXlab platform.
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Airtightness estimation a state of the art review and an en route upper limit evaluation principle to increase the chances that wood frame houses with a vapour and wind barrier comply with the Airtightness requirements
Energy and Buildings, 2012Co-Authors: Thoroskar Relander, Sverre Holos, Jan Vincent ThueAbstract:Abstract High Airtightness is particularly important in order to achieve energy efficient buildings. Of this reason Airtightness estimation is of interest. Over the past 30 years researchers have worked on Airtightness estimation. This article is divided into two parts. The 1st part deals with earlier work on Airtightness estimation. It is seen that there are relatively few references in the literature that deal with estimation of Airtightness. None of the reviewed references argue that Airtightness measurements can be replaced by estimates. The only reference that deals with Airtightness estimation of wood-frame houses with high Airtightness did not manage to find a correlation between the estimated and the measured Airtightness. For a contractor what really matters is not an estimate of the Airtightness of the finished building, but a reliable means to be sure of reaching the Airtightness requirement. It is therefore customary to perform blower-door tests stepwise during the construction process. First the Airtightness of the building with the wind-barrier is measured, n 50w . Then the Airtightness of the finished building that also has a vapour barrier is measured, n 50f . The Airtightness requirement is set for n 50f . Of various reasons it is not given that n 50f n 50w for a given building, and consequently one should have an idea of what an upper limit of n 50w should be in order to be confident to reach the n 50f requirement. In the 2nd part of the article it will be shown how this upper limit of n 50w can be found by statistical analysis based on systematic measurements of n 50w and n 50f as part of a quality assurance system.
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Airtightness estimation—A state of the art review and an en route upper limit evaluation principle to increase the chances that wood-frame houses with a vapour- and wind-barrier comply with the Airtightness requirements
Energy and Buildings, 2012Co-Authors: Thoroskar Relander, Sverre Holos, Jan Vincent ThueAbstract:Abstract High Airtightness is particularly important in order to achieve energy efficient buildings. Of this reason Airtightness estimation is of interest. Over the past 30 years researchers have worked on Airtightness estimation. This article is divided into two parts. The 1st part deals with earlier work on Airtightness estimation. It is seen that there are relatively few references in the literature that deal with estimation of Airtightness. None of the reviewed references argue that Airtightness measurements can be replaced by estimates. The only reference that deals with Airtightness estimation of wood-frame houses with high Airtightness did not manage to find a correlation between the estimated and the measured Airtightness. For a contractor what really matters is not an estimate of the Airtightness of the finished building, but a reliable means to be sure of reaching the Airtightness requirement. It is therefore customary to perform blower-door tests stepwise during the construction process. First the Airtightness of the building with the wind-barrier is measured, n 50w . Then the Airtightness of the finished building that also has a vapour barrier is measured, n 50f . The Airtightness requirement is set for n 50f . Of various reasons it is not given that n 50f n 50w for a given building, and consequently one should have an idea of what an upper limit of n 50w should be in order to be confident to reach the n 50f requirement. In the 2nd part of the article it will be shown how this upper limit of n 50w can be found by statistical analysis based on systematic measurements of n 50w and n 50f as part of a quality assurance system.
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the influence of structural floors on the Airtightness of wood frame houses
Energy and Buildings, 2011Co-Authors: Thoroskar Relander, Staf Roels, Jan Vincent Thue, Geert Bauwens, Sivert UvslokkAbstract:Energy use in buildings has come more into focus in recent years. An airtight building envelope with a low infiltration is a definite prerequisite to achieve an energy efficient building. Recently the Norwegian Airtightness requirements have become stricter. This leads to an increased focus on airtight constructions and methods. Platform constructed structural floors are widely used in Norway. Air leakages are frequently observed in connection with structural floors, both at the wall/floor and wall/ceiling junction and as leakages into the floor or into the ceiling. This article discusses the importance of the leakages in platform constructed structural floors on the Airtightness of wood-frame houses. This is done by laboratory measurements of vapour barriers and wind-barriers mounted on a wall with structural floor beams. The results show that the Airtightness performance of the vapour barrier can be made almost as good as the wind-barrier. However, this is quite labour-intensive. With a properly mounted wind-barrier, the influence of the structural floors on the Airtightness of a wood-frame house can be made negligible.
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The influence of structural floors on the Airtightness of wood-frame houses
Energy and Buildings, 2011Co-Authors: Thoroskar Relander, Staf Roels, Jan Vincent Thue, Geert Bauwens, Sivert UvslokkAbstract:Energy use in buildings has come more into focus in recent years. An airtight building envelope with a low infiltration is a definite prerequisite to achieve an energy efficient building. Recently the Norwegian Airtightness requirements have become stricter. This leads to an increased focus on airtight constructions and methods. Platform constructed structural floors are widely used in Norway. Air leakages are frequently observed in connection with structural floors, both at the wall/floor and wall/ceiling junction and as leakages into the floor or into the ceiling. This article discusses the importance of the leakages in platform constructed structural floors on the Airtightness of wood-frame houses. This is done by laboratory measurements of vapour barriers and wind-barriers mounted on a wall with structural floor beams. The results show that the Airtightness performance of the vapour barrier can be made almost as good as the wind-barrier. However, this is quite labour-intensive. With a properly mounted wind-barrier, the influence of the structural floors on the Airtightness of a wood-frame house can be made negligible.status: publishe
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the influence of lightweight aggregate concrete element chimneys on the Airtightness of wood frame houses
Energy and Buildings, 2010Co-Authors: Thoroskar Relander, Tore Kvande, Jan Vincent ThueAbstract:Energy efficient buildings must be constructed as airtight as possible. In Norway the Airtightness requirements have become stricter. This leads to a growing interest for airtight constructions and methods. Element chimneys of lightweight aggregate concrete, LWAC, are widely used in Norway. Air leakages are frequently observed in connection with these chimneys. The leaks are found either through the element, as a result of insufficient surface treatment of the air permeable element, or through the joint with the roof. This article discusses the influence that LWAC element chimneys can have on the Airtightness of wood-frame houses. This is done by measurements and calculations. The influence of the sealing method used in the joint with the roof and the influence of the surface treatment of the LWAC elements on the Airtightness is investigated. The results show that even the simplest sealing in the joint with the roof is adequate because of the limited circumference of the LWAC chimney. The results also show that the Airtightness provided by the surface treatment of the chimney is very sensitive to the workmanship. If the workmanship is thorough, the influence of a LWAC element chimney on the Airtightness of a wood-frame house should be negligible.
Arnold Janssens - One of the best experts on this subject based on the ideXlab platform.
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Airtightness and watertightness of window frames comparison of performance and requirements
Building and Environment, 2016Co-Authors: Nathan Van Den Bossche, Arnold JanssensAbstract:Abstract Airtight buildings require airtight windows. To date little information is available on the typical Airtightness of window frames, and the aptitude of current regulatory performance levels for windows in respect to very airtight buildings is highly uncertain. Between 1997 and 2012, 437 windows were tested in laboratory conditions for certification; the most important results in respect to Airtightness and watertightness are reported here. For both parameters, vinyl frames yield slightly lower performance than aluminum or wooden windows. Single windows perform best, followed by double, composed and sliding windows. Window Airtightness performance levels were calculated based on various building geometries and Airtightness targets. Reducing the impact of windows on the overall building Airtightness to 5% is realistic and feasible, even for very airtight buildings. The test results clearly demonstrate that Airtightness, watertightness and resistance to wind loads are partially correlated. A comparison of guidelines and standards on watertightness of windows shows large discrepancies and little uniformity. Most turn-and-tilt windows show good watertightness and can be applied to very exposed conditions, whereas sliding windows have a limited scope.
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durability and measurement uncertainty of Airtightness in extremely airtight dwellings
International Journal of Ventilation, 2016Co-Authors: Wolf Bracke, Nathan Van Den Bossche, Jelle Laverge, Arnold JanssensAbstract:AbstractIn this paper a series of leakage tests is presented on extremely airtight dwellings, studying the durability of the Airtightness level and the measurement uncertainty involved. All houses subjected to testing are certificated passive houses, meaning the maximum air leakage rate upon completion was n50 < 0.6 h-1 air changes per hour at 50 Pa pressure difference.In the literature, repeatability and reproducibility issues have been discussed by several authors, along with influences of weather conditions. However, it remains unclear to what extent the available uncertainty intervals are relative or absolute. With the current tendency towards extremely low leakage levels and the introduction of Airtightness requirements in building codes, the further exploration of this issue has become crucial.Four aspects concerning air leakage tests are examined: the repeatability and reproducibility of the fan pressurization results in extremely airtight houses, the impact of weather conditions on the measurement...
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Airtightness of the window-wall interface in wood-frame walls
2014Co-Authors: Wolf Bracke, Nathan Van Den Bossche, Lynn Devos, Silke Maertens, Arnold JanssensAbstract:Due to the increased focus on Airtightness in the current building practice, a better understanding of air leakage rates through different building components and building interfaces is required. This paper investigates the Airtightness of the window-wall interface in wood-frame constructions through a literature review and experimental study. Different wall setups, window installation methods and air sealing solutions were tested resulting in 20 different configurations. Air leakages rates ranging from 0.00 up to 3.66 m3/h.m at 50 Pa are measured and recommended configurations and installation techniques are discussed. The results show that a passive house level Airtightness is achievable when using spray-in-place polyurethane foam or airtight membranes, if some general guidelines are followed.
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Airtightness of the window-wall interface in masonry brick walls
2013Co-Authors: Nathan Van Den Bossche, Willem Huyghe, Jan Moens, Arnold JanssensAbstract:In recent decades there has been an increased focus on enhanced thermal resistance of building components and as a consequence, the relative importance of Airtightness on the overall energy losses of buildings has increased significantly. The construction industry requires practical information on the Airtightness of individual construction elements and building envelope interfaces. A literature review on the Airtightness of window-wall interfaces has shown that no experimental data are available for masonry construction. This paper offers an investigative study on the Airtightness of window-wall interfaces of masonry walls, for 13 different installation methods. The results show that the selected solutions cover a wide range of Airtightness levels, from 0m³/h.m up to 31m³/h.m at 50 Pa. The experiments have permitted determining that a very good performance can be obtained by using polyurethane foam and caulking, airtight membranes, polyurethane foam and plywood framing, and plaster and caulking. On the contrary, mineral fibre insulation, a partial fill with polyurethane foam and plaster without caulking should be avoided when good Airtightness is required. Furthermore, a comprehensive methodology for error calculation is offered, based on error propagation of partially correlated parameters, including the effect of measurement errors, extraneous air leakage and conversion to standard boundary conditions.
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durability and measurement uncertainty of Airtightness in extremely airtight dwellings
34th AIVC Conference: Energy conservation technologies for mitigation and adaptation in the built environment: the role of ventilation strategies and , 2013Co-Authors: Wolf Bracke, Nathan Van Den Bossche, Jelle Laverge, Arnold JanssensAbstract:In this paper we present a series of leakage tests on extremely airtight dwellings (ACH50 < 0.6 upon completion) in which the durability of the Airtightness and the measurement uncertainty involved are assessed. In literature, repeatability and reproducibility issues have been discussed by several authors, along with influences of weather. It remains unclear, however, to what extent the available uncertainty intervals are relative or absolute. With the current tendency towards extremely low leakage levels and the introduction of Airtightness requirements in building codes, the further exploration of this issue has become crucial.
Nathan Van Den Bossche - One of the best experts on this subject based on the ideXlab platform.
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Airtightness of sealed building joints: Comparison of performance before and after artificial ageing
Building and Environment, 2020Co-Authors: Stéphanie Van Linden, Nathan Van Den BosscheAbstract:Abstract Airtightness is considered an important factor on all levels of the building envelope, i.e. overall building envelope, on a component level and on a material level. Airtightness of the building envelope is a defining factor to achieve energy efficient and durable buildings, i.e. reduced risk of condensation and water infiltration through the building envelope, reduced risk of cold draughts and it improves the correct functioning of the HVAC-system. Over the past decades the amount of Airtightness tests for newly built buildings in Belgium has significantly increased. However, the measured Airtightness level of the tested buildings from 2006 to 2016 did not significantly change. This implies that there is still a lack of knowledge to achieve airtight building details, both on a design level and on the implementation of the building details. However, literature concerning Airtightness of sealed building joints is very limited. In this study, the Airtightness performance of different materials to seal building joints was experimentally assessed. In general, a good Airtightness was achieved for all tested materials in case they were perfectly installed. However, the performance of the sealing materials was very sensitive to faulty workmanship and primarily depended on the quality of implementation, in particular for the tapes, silicone based materials and foam sealing strips. The performance of the liquid applied coating primarily depended on the characteristics of the materials and the application method was determining for the performance of the polyurethane foams.
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Airtightness and watertightness of window frames comparison of performance and requirements
Building and Environment, 2016Co-Authors: Nathan Van Den Bossche, Arnold JanssensAbstract:Abstract Airtight buildings require airtight windows. To date little information is available on the typical Airtightness of window frames, and the aptitude of current regulatory performance levels for windows in respect to very airtight buildings is highly uncertain. Between 1997 and 2012, 437 windows were tested in laboratory conditions for certification; the most important results in respect to Airtightness and watertightness are reported here. For both parameters, vinyl frames yield slightly lower performance than aluminum or wooden windows. Single windows perform best, followed by double, composed and sliding windows. Window Airtightness performance levels were calculated based on various building geometries and Airtightness targets. Reducing the impact of windows on the overall building Airtightness to 5% is realistic and feasible, even for very airtight buildings. The test results clearly demonstrate that Airtightness, watertightness and resistance to wind loads are partially correlated. A comparison of guidelines and standards on watertightness of windows shows large discrepancies and little uniformity. Most turn-and-tilt windows show good watertightness and can be applied to very exposed conditions, whereas sliding windows have a limited scope.
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durability and measurement uncertainty of Airtightness in extremely airtight dwellings
International Journal of Ventilation, 2016Co-Authors: Wolf Bracke, Nathan Van Den Bossche, Jelle Laverge, Arnold JanssensAbstract:AbstractIn this paper a series of leakage tests is presented on extremely airtight dwellings, studying the durability of the Airtightness level and the measurement uncertainty involved. All houses subjected to testing are certificated passive houses, meaning the maximum air leakage rate upon completion was n50 < 0.6 h-1 air changes per hour at 50 Pa pressure difference.In the literature, repeatability and reproducibility issues have been discussed by several authors, along with influences of weather conditions. However, it remains unclear to what extent the available uncertainty intervals are relative or absolute. With the current tendency towards extremely low leakage levels and the introduction of Airtightness requirements in building codes, the further exploration of this issue has become crucial.Four aspects concerning air leakage tests are examined: the repeatability and reproducibility of the fan pressurization results in extremely airtight houses, the impact of weather conditions on the measurement...
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Airtightness of the window-wall interface in wood-frame walls
2014Co-Authors: Wolf Bracke, Nathan Van Den Bossche, Lynn Devos, Silke Maertens, Arnold JanssensAbstract:Due to the increased focus on Airtightness in the current building practice, a better understanding of air leakage rates through different building components and building interfaces is required. This paper investigates the Airtightness of the window-wall interface in wood-frame constructions through a literature review and experimental study. Different wall setups, window installation methods and air sealing solutions were tested resulting in 20 different configurations. Air leakages rates ranging from 0.00 up to 3.66 m3/h.m at 50 Pa are measured and recommended configurations and installation techniques are discussed. The results show that a passive house level Airtightness is achievable when using spray-in-place polyurethane foam or airtight membranes, if some general guidelines are followed.
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Airtightness of the window-wall interface in masonry brick walls
2013Co-Authors: Nathan Van Den Bossche, Willem Huyghe, Jan Moens, Arnold JanssensAbstract:In recent decades there has been an increased focus on enhanced thermal resistance of building components and as a consequence, the relative importance of Airtightness on the overall energy losses of buildings has increased significantly. The construction industry requires practical information on the Airtightness of individual construction elements and building envelope interfaces. A literature review on the Airtightness of window-wall interfaces has shown that no experimental data are available for masonry construction. This paper offers an investigative study on the Airtightness of window-wall interfaces of masonry walls, for 13 different installation methods. The results show that the selected solutions cover a wide range of Airtightness levels, from 0m³/h.m up to 31m³/h.m at 50 Pa. The experiments have permitted determining that a very good performance can be obtained by using polyurethane foam and caulking, airtight membranes, polyurethane foam and plywood framing, and plaster and caulking. On the contrary, mineral fibre insulation, a partial fill with polyurethane foam and plaster without caulking should be avoided when good Airtightness is required. Furthermore, a comprehensive methodology for error calculation is offered, based on error propagation of partially correlated parameters, including the effect of measurement errors, extraneous air leakage and conversion to standard boundary conditions.
Staf Roels - One of the best experts on this subject based on the ideXlab platform.
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the influence of structural floors on the Airtightness of wood frame houses
Energy and Buildings, 2011Co-Authors: Thoroskar Relander, Staf Roels, Jan Vincent Thue, Geert Bauwens, Sivert UvslokkAbstract:Energy use in buildings has come more into focus in recent years. An airtight building envelope with a low infiltration is a definite prerequisite to achieve an energy efficient building. Recently the Norwegian Airtightness requirements have become stricter. This leads to an increased focus on airtight constructions and methods. Platform constructed structural floors are widely used in Norway. Air leakages are frequently observed in connection with structural floors, both at the wall/floor and wall/ceiling junction and as leakages into the floor or into the ceiling. This article discusses the importance of the leakages in platform constructed structural floors on the Airtightness of wood-frame houses. This is done by laboratory measurements of vapour barriers and wind-barriers mounted on a wall with structural floor beams. The results show that the Airtightness performance of the vapour barrier can be made almost as good as the wind-barrier. However, this is quite labour-intensive. With a properly mounted wind-barrier, the influence of the structural floors on the Airtightness of a wood-frame house can be made negligible.
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Hygrothermal response of highly insulated timber frame walls with an exterior air barrier system: laboratory investigation
9th Nordic Symposium on Building Physics, 2011Co-Authors: Jelle Langmans, Ralf Klein, Staf RoelsAbstract:As a result of improved Airtightness of wind barriers recent pressurisation tests showed that wind barriers can have a major contribution to the global Airtightness of timber frame constructions. The advantage is that wind barriers show fewer joints and less perforations compared to an interior air barrier system. Consequently, it is questioned whether the labour intensive interior air barrier is still necessary when the Airtightness can be guaranteed by the wind barrier only. However, hygrothermal risks involved in moving the air barrier from the interior to the exterior of the building envelope are unknown for cold and moderate climates since this topic is yet unstudied. The current paper presents an ongoing laboratory experiment to study the hygrothermal behaviour of light weight timber walls with only an exterior air barrier. Four independent highly insulated test walls (2.3m by 0.5m) are placed between a newly developed hot and cold box, operating at controlled temperatures, humidities and air pressures. The test walls are exposed to different boundary conditions during four consecutive measuring stages. Preliminary results, with the emphasis on the thermal behaviour of the test walls during the first stage, are presented in the current paper.
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The influence of structural floors on the Airtightness of wood-frame houses
Energy and Buildings, 2011Co-Authors: Thoroskar Relander, Staf Roels, Jan Vincent Thue, Geert Bauwens, Sivert UvslokkAbstract:Energy use in buildings has come more into focus in recent years. An airtight building envelope with a low infiltration is a definite prerequisite to achieve an energy efficient building. Recently the Norwegian Airtightness requirements have become stricter. This leads to an increased focus on airtight constructions and methods. Platform constructed structural floors are widely used in Norway. Air leakages are frequently observed in connection with structural floors, both at the wall/floor and wall/ceiling junction and as leakages into the floor or into the ceiling. This article discusses the importance of the leakages in platform constructed structural floors on the Airtightness of wood-frame houses. This is done by laboratory measurements of vapour barriers and wind-barriers mounted on a wall with structural floor beams. The results show that the Airtightness performance of the vapour barrier can be made almost as good as the wind-barrier. However, this is quite labour-intensive. With a properly mounted wind-barrier, the influence of the structural floors on the Airtightness of a wood-frame house can be made negligible.status: publishe
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potential of wind barriers to assure Airtightness of wood frame low energy constructions
Energy and Buildings, 2010Co-Authors: Jelle Langmans, Michel De Paepe, Ralf Klein, Staf RoelsAbstract:Abstract This paper investigates the Airtightness of a wood-frame passive house during the consecutive construction stages. Aim is to investigate whether an acceptable Airtightness can be achieved by the external wind barrier only. The wind barrier consists of a promising new type of asphalt impregnated fibreboards. To quantify the different leakage paths, the study applies the reductive sealing technique. In total 12 pressurisation tests have been conducted during the construction process. In addition to these field tests on the entire building, the paper discusses the results from laboratory measurements on specimens of the wind barrier including typical joints, in order to verify the influence of different possible types of local air leakage paths. The results reveal that the external wind barrier has a significant Airtightness. Moreover, by sealing only the most critical joints of the outer shell, the overall Airtightness of the studied case fulfils the requirements of the passive house standard (less than 0.6 air changes per hour (ACH) at 50 Pa). The results presented in this paper, thus, indicate that the proposed solution may have potential to reduce the labour costs required to reach a sufficient level of Airtightness.
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Feasibility of Using Wind Barriers as Air Barriers in Wood Frame Construction
Thermal Performance of the Exterior Envelopes of Whole Buildings XI International Conference, 2010Co-Authors: Jelle Langmans, Michel De Paepe, Staf Roels, Ralf Klein, Paul EykensAbstract:Airtightness of building envelopes is one of the most important properties of low-energy buildings. For lightweight construc- tion, an airtight building envelope is commonly realized by an interior air- and vapor-tight barrier. Realizing an interior air barrier is, however, often labor intensive due to many internal joints and potential penetrations for electrical and plumbing services. Based on recent improvements to the Airtightness of wind barriers, the idea arose to move the air barrier to the outside of the building envelope. Moving the airtight layer to the outside of the building envelope means fewer joints and less risk for pene- trations. This paper investigates the air permeability of a wind barrier during consecutive construction stages of a wood-frame passive house located in Belgium. The wind barrier consists of asphalt-impregnated fiberboard. Measurements were taken before and after sealing the joints in this exterior layer. In total, 12 pressurization tests were carried out. The results reveal that by sealing only the most critical joints of this outer shell, a sufficient level of Airtightness can be achieved. The proposed solution may therefore have significant potential to reduce labor costs for Airtightness in low-energy buildings.