The Experts below are selected from a list of 651 Experts worldwide ranked by ideXlab platform
Berit Time - One of the best experts on this subject based on the ideXlab platform.
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external wood claddings performance criteria Driving Rain and large scale water penetration methods
Wood Material Science and Engineering, 2015Co-Authors: Petra Rüther, Berit TimeAbstract:AbstractIn Norway, wood is widely used as an external cladding material. The performance requirements of a facade cladding can be divided into technical and aesthetic performance, where the technical performance is more distinct than the aesthetic one. Performance models for technical performance of wooden facades and deckings are under development and there is also ongoing research on the parameters that affect aesthetic performance. Wooden facades are recommended to be designed as a two-step tightening with a ventilated air gap and dRainage opening on the back. The technical performance is mainly related to the ability of the construction to withstand wind-driven Rain and the drying out potential of the chosen material and solutions.This work presents the results from a large-scale laboratory trial on three different wooden cladding solutions. The objective was to investigate the Rain tightness of the different types of cladding, to detect water that penetrates the cladding and monitor the uptake of moi...
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External wood claddings – performance criteria, Driving Rain and large-scale water penetration methods
Wood Material Science & Engineering, 2015Co-Authors: Petra Rüther, Berit TimeAbstract:AbstractIn Norway, wood is widely used as an external cladding material. The performance requirements of a facade cladding can be divided into technical and aesthetic performance, where the technical performance is more distinct than the aesthetic one. Performance models for technical performance of wooden facades and deckings are under development and there is also ongoing research on the parameters that affect aesthetic performance. Wooden facades are recommended to be designed as a two-step tightening with a ventilated air gap and dRainage opening on the back. The technical performance is mainly related to the ability of the construction to withstand wind-driven Rain and the drying out potential of the chosen material and solutions.This work presents the results from a large-scale laboratory trial on three different wooden cladding solutions. The objective was to investigate the Rain tightness of the different types of cladding, to detect water that penetrates the cladding and monitor the uptake of moi...
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interior insulation retrofit of a historical brick wall using vacuum insulation panels hygrothermal numerical simulations and laboratory investigations
Building and Environment, 2014Co-Authors: Par Johansson, Stig Geving, Carleric Hagentoft, Bjorn Petter Jelle, Egil Rognvik, Angela Sasic Kalagasidis, Berit TimeAbstract:Old listed buildings need to be retrofitted to reduce the energy use for heating. The possible thickness of the insulation layer is limited by the existing construction. Vacuum insulation panels (VIPs) require less thickness than conventional insulation materials to reach the same thermal resistance. Therefore, it could be more appropriate to use VIPs than conventional insulation materials when retrofitting the building envelope of listed buildings. The aim of this study is to investigate the hygrothermal performance of a brick wall with wooden beam ends after it was insulated on the interior with VIPs. One- and two-dimensional hygrothermal numerical simulations were used to design a laboratory study in a large-scale building envelope climate simulator. The wall was exposed to Driving Rain on the exterior surface and a temperature gradient. The relative humidity in the wall increased substantially when exposed to Driving Rain. The moisture content in the wooden beams also increased. There was no significant difference between the relative humidity in the wooden beam ends for the cases with and without VIPs. However, it was found that the reduced temperature in the brick after the VIPs were added led to a higher relative humidity in the wooden beams. It was also clear that when VIPs were added to the interior, the drying capacity to that side of the wall was substantially reduced. Finally, calculations of the U-value showed a large potential to reduce the energy use using VIPs on the interior of brick walls.
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Retrofitting a brick wall using vacuum insulation panels: measured hygrothermal effect on the existing structure
2014Co-Authors: Par Johansson, Stig Geving, Carleric Hagentoft, Bjorn Petter Jelle, Egil Rognvik, Angela Sasic Kalagasidis, Berit TimeAbstract:Old listed buildings need to be retrofitted to reduce the energy use for heating. Vacuum insulation panels (VIPs) require less thickness than conventional insulation materials to reach the same thermal resistance. The aim of this paper is to investigate the hygrothermal performance of a brick wall with wooden beam ends after it was insulated on the interior with VIPs. The paper presents the first part of a laboratory study where a brick wall was built in the laboratory and exposed to simulated Driving Rain. Different measurement techniques of the relative humidity in the construction have been used. The relative humidity in the wall increased substantially when exposed to Driving Rain. The moisture content in the wooden beams also increased. However, it has not been possible to fully determine the influence by the added insulation layer. It is clear that the drying capacity to the interior side is substantially reduced. These investigations are ongoing and will be reported in future publications.
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Interior Insulation Retrofit of a Brick Wall Using Vacuum Insulation Panels: Design of a Laboratory Study to Determine the Hygrothermal Effect on Existing Structure and Wooden Beam Ends
2013Co-Authors: Par Johansson, Stig Geving, Carleric Hagentoft, Bjorn Petter Jelle, Angela Sasic Kalagasidis, Berit Time, Egil RognvikAbstract:The increasing demand on energy-efficient buildings requires energy retrofitting measures in the existing building stock. Conventional thermal insulation materials, such as mineral wool and expanded polystyrene (EPS), demand a thick layer of insulation to reach the energy targets. Vacuum insulation panels (VIPs) are a novel thermal insulation component with 5-10 times lower thermal conductivity than the conventional insulation materials, depending on the VIP ageing state. The thermal transmittance of the building envelope can thereby be substantially reduced using a limited additional insulation thickness. Previous research has shown that interior energy retrofitting of exterior walls may increase the moisture content of the walls and increases the risk of freeze-thaw damages at the surface. This study analyzes the hygrothermal consequences on a 250 mm (9.8 in.) thick brick wall retrofitted with 20 mm (0.8 in.) interior VIP (glued directly on the plastered brick wall). Hygrothermal simulations in WUFI 2D are used to study the hygrothermal effects by different material properties and boundary conditions. Apart from the material properties, the amount of Driving Rain available at the surface is the most important influential parameter in the simulations. The conclusions from this study are used to plan a measurement study in a climate simulator where Driving Rain and solar radiation will be simulated.
Enrique Cano-suñén - One of the best experts on this subject based on the ideXlab platform.
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On the significance of the climate-dataset time resolution in characterising wind-driven Rain and simultaneous wind pressure. Part I: scalar approach
Stochastic Environmental Research and Risk Assessment, 2018Co-Authors: José M. Pérez-bella, Javier Domínguez-hernández, Enrique Cano-suñén, Juan J. Coz-díaz, Mar Alonso-martínezAbstract:The joint action of wind-driven Rain and wind pressure is the main cause of water penetration in building facades, which causes various habitability and durability problems. The most widespread characterisation of both climate factors is based on exposure indices calculated in free-field conditions from records of precipitation—wind speed (scalar indices), adding wind direction for directional indices. The time resolution of this climate dataset defines the calculation effort and the accuracy obtained, and average daily, monthly, or annual records are typical due to their greater availability. This paper investigates the influence of this time resolution on the accuracy of these scalar exposure indices (Driving Rain index, hereafter aDRI, and Driving-Rain wind pressure, hereafter DRWP) by assessing the nature and magnitude of errors associated with different averaged records. For this purpose, 10-min, hourly, daily, monthly and annual meteorological data collected over 15 years in 6 Spanish weather stations at locations characterised by different environments and topography are analysed. In addition, relationships capable of adjusting indices of any time resolution to an accuracy similar to that reached through 10-min records are proposed. In general, the value of Driving-Rain wind pressure exhibits greater sensitivity than the Driving Rain index at this time resolution, incorporating significant errors even with daily datasets. In turn, the use of monthly and annual records should be reconsidered, given their high uncertainty. The results demonstrate how the daily datasets for aDRI indices and hourly datasets for DRWP values are sufficient to characterise these exposures with errors of less than 11%.
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On the significance of the climate-dataset time resolution in characterising wind-driven Rain and simultaneous wind pressure. Part II: directional analysis
Stochastic Environmental Research and Risk Assessment, 2017Co-Authors: José M. Pérez-bella, Javier Domínguez-hernández, Juan J. Del Coz-díaz, Enrique Cano-suñén, Felipe Pedro Álvarez RabanalAbstract:Both semi-empirical methods and CFD simulations use real climate datasets as a basis for determining the building facade exposure to wind-driven Rain and simultaneous wind pressure. The time resolution of these datasets and the number of variables considered (commonly Rainfall intensity, wind speed and wind direction) determine the required calculation effort and the accuracy of the result. Omitting the wind direction, a former article (Part I of this research) has analysed the effect of this time resolution on two scalar exposure indices obtained by semi-empirical methods: Driving Rain index (aDRI) and Driving-Rain wind pressure (DRWP). However, the wind direction during precipitation events also causes significant exposure variations between possible facade orientations. Thus, it is also necessary to clarify the influence of the time resolution of the dataset, on the accuracy of the directional semi-empirical calculation of aDRI and DRWP. To meet this challenge, the article examines 10-min climate records collected between 2001 and 2016 at 6 Spanish locations, uses them to obtain hourly, daily, monthly and annual datasets, and analyses the accuracy of the directional exposure indices associated with each time resolution. The results show that a daily dataset would allow identifying the most exposed orientation with an error less than 45°. However, even the hourly datasets cause errors close to 10% in the exposure values identified on each facade orientation. Finally, adjustment relationships that allow estimating the maximum value of directional exposure from simple scalar indices are obtained.
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Assessment of water penetration risk in building facades throughout Brazil
Building Research & Information, 2016Co-Authors: Javier Domínguez-hernández, José M. Pérez-bella, Enrique Cano-suñén, Mar Alonso-martínez, J.j. Del Coz-díazAbstract:ABSTRACTThe penetration of atmospheric water (Rain) into facades creates problems for building habitability and the durability of construction materials. This study analyses the exposure of Brazilian facades to the two main climate factors responsible for this penetration: wind-driven Rain and Driving Rain wind pressure. Daily weather records (spanning 2005–14, from 171 weather stations) were analysed. Both exposure factors were combined to assess the risk of water penetration at each site. The relationships between the different exposure indices calculated from daily, monthly and annual records were determined and compared with results from other countries. From this analysis, detailed isopleth maps are provided that allow a graphical characterization of the moisture exposure conditions of facades anywhere in Brazil. A comprehensive characterization of the water penetration exposure in Brazilian enclosures is created and can be used to establish normative design requirements for actual climatic condition...
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Optimised method for estimating directional Driving Rain from synoptic observation data
Journal of Wind Engineering and Industrial Aerodynamics, 2013Co-Authors: José M. Pérez-bella, Javier Domínguez-hernández, Beatriz Rodríguez-soria, Juan J. Del Coz-díaz, Enrique Cano-suñénAbstract:In this article, the annual directional exposure to Driving Rain and its characteristics are analysed and discussed at four Spanish sites that are characterised by different Rainfall levels and topographical and wind conditions. For this study, the present weather observation method is used, which is based on average annual Rainfall data and synoptic observations of the present weather. The results of this study are compared with those obtained by applying the ISO 15927-3:2009 standard, which is based on the semi-empirical analysis of hourly wind and Rainfall data. This study identifies the intrinsic dependence of the aforementioned synoptic method on the weather conditions that exist at each site, which affect the reliability and accuracy of the estimates. Thus, corrective changes that would enable the synoptic method to generate more reliable approximations are proposed, and a new optimised methodology is presented; the precision of the new method relies on synoptic observations but is independent of weather conditions. The results, validated at four Spanish sites, suggest that in the absence of hourly data for implementing the ISO standard, this optimised synoptic method is able to generate reasonably accurate estimates of the annual directional exposure to Driving Rain, regardless of the particular site conditions.
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Combined use of wind-driven Rain and wind pressure to define water penetration risk into building façades: The Spanish case
Building and Environment, 2013Co-Authors: José M. Pérez-bella, Javier Domínguez-hernández, Beatriz Rodríguez-soria, Juan J. Del Coz-díaz, Enrique Cano-suñénAbstract:Abstract This article defines a new index to characterise the risk of atmospheric water penetration into building enclosures. This risk index integrates the two most relevant exposure parameters for this phenomenon into a single value, combining the water supply presented by Driving Rain and simultaneous wind pressure on the surface of the enclosure. Compared with the usual wind-driven Rain exposure maps, the inclusion of Driving Rain wind pressure in this index permits a more complete assessment of the risk of penetration. Therefore, this index represents a powerful tool for defining more appropriate facade solutions for exposures that result in atmospheric water penetration. This risk index was calculated for 80 Spanish sites scattered around the Iberian Peninsula and the Canary and Balearic Islands using daily precipitation averages and wind speed averages for each location collected over 30 years. As a result, a risk index map has been produced for Spain. The risk characterisation obtained in this study enables an objective improvement of current Spanish building regulations governing the design of facades against the penetration of atmospheric water.
José M. Pérez-bella - One of the best experts on this subject based on the ideXlab platform.
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On the significance of the climate-dataset time resolution in characterising wind-driven Rain and simultaneous wind pressure. Part I: scalar approach
Stochastic Environmental Research and Risk Assessment, 2018Co-Authors: José M. Pérez-bella, Javier Domínguez-hernández, Enrique Cano-suñén, Juan J. Coz-díaz, Mar Alonso-martínezAbstract:The joint action of wind-driven Rain and wind pressure is the main cause of water penetration in building facades, which causes various habitability and durability problems. The most widespread characterisation of both climate factors is based on exposure indices calculated in free-field conditions from records of precipitation—wind speed (scalar indices), adding wind direction for directional indices. The time resolution of this climate dataset defines the calculation effort and the accuracy obtained, and average daily, monthly, or annual records are typical due to their greater availability. This paper investigates the influence of this time resolution on the accuracy of these scalar exposure indices (Driving Rain index, hereafter aDRI, and Driving-Rain wind pressure, hereafter DRWP) by assessing the nature and magnitude of errors associated with different averaged records. For this purpose, 10-min, hourly, daily, monthly and annual meteorological data collected over 15 years in 6 Spanish weather stations at locations characterised by different environments and topography are analysed. In addition, relationships capable of adjusting indices of any time resolution to an accuracy similar to that reached through 10-min records are proposed. In general, the value of Driving-Rain wind pressure exhibits greater sensitivity than the Driving Rain index at this time resolution, incorporating significant errors even with daily datasets. In turn, the use of monthly and annual records should be reconsidered, given their high uncertainty. The results demonstrate how the daily datasets for aDRI indices and hourly datasets for DRWP values are sufficient to characterise these exposures with errors of less than 11%.
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On the significance of the climate-dataset time resolution in characterising wind-driven Rain and simultaneous wind pressure. Part II: directional analysis
Stochastic Environmental Research and Risk Assessment, 2017Co-Authors: José M. Pérez-bella, Javier Domínguez-hernández, Juan J. Del Coz-díaz, Enrique Cano-suñén, Felipe Pedro Álvarez RabanalAbstract:Both semi-empirical methods and CFD simulations use real climate datasets as a basis for determining the building facade exposure to wind-driven Rain and simultaneous wind pressure. The time resolution of these datasets and the number of variables considered (commonly Rainfall intensity, wind speed and wind direction) determine the required calculation effort and the accuracy of the result. Omitting the wind direction, a former article (Part I of this research) has analysed the effect of this time resolution on two scalar exposure indices obtained by semi-empirical methods: Driving Rain index (aDRI) and Driving-Rain wind pressure (DRWP). However, the wind direction during precipitation events also causes significant exposure variations between possible facade orientations. Thus, it is also necessary to clarify the influence of the time resolution of the dataset, on the accuracy of the directional semi-empirical calculation of aDRI and DRWP. To meet this challenge, the article examines 10-min climate records collected between 2001 and 2016 at 6 Spanish locations, uses them to obtain hourly, daily, monthly and annual datasets, and analyses the accuracy of the directional exposure indices associated with each time resolution. The results show that a daily dataset would allow identifying the most exposed orientation with an error less than 45°. However, even the hourly datasets cause errors close to 10% in the exposure values identified on each facade orientation. Finally, adjustment relationships that allow estimating the maximum value of directional exposure from simple scalar indices are obtained.
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Assessment of water penetration risk in building facades throughout Brazil
Building Research & Information, 2016Co-Authors: Javier Domínguez-hernández, José M. Pérez-bella, Enrique Cano-suñén, Mar Alonso-martínez, J.j. Del Coz-díazAbstract:ABSTRACTThe penetration of atmospheric water (Rain) into facades creates problems for building habitability and the durability of construction materials. This study analyses the exposure of Brazilian facades to the two main climate factors responsible for this penetration: wind-driven Rain and Driving Rain wind pressure. Daily weather records (spanning 2005–14, from 171 weather stations) were analysed. Both exposure factors were combined to assess the risk of water penetration at each site. The relationships between the different exposure indices calculated from daily, monthly and annual records were determined and compared with results from other countries. From this analysis, detailed isopleth maps are provided that allow a graphical characterization of the moisture exposure conditions of facades anywhere in Brazil. A comprehensive characterization of the water penetration exposure in Brazilian enclosures is created and can be used to establish normative design requirements for actual climatic condition...
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Optimised method for estimating directional Driving Rain from synoptic observation data
Journal of Wind Engineering and Industrial Aerodynamics, 2013Co-Authors: José M. Pérez-bella, Javier Domínguez-hernández, Beatriz Rodríguez-soria, Juan J. Del Coz-díaz, Enrique Cano-suñénAbstract:In this article, the annual directional exposure to Driving Rain and its characteristics are analysed and discussed at four Spanish sites that are characterised by different Rainfall levels and topographical and wind conditions. For this study, the present weather observation method is used, which is based on average annual Rainfall data and synoptic observations of the present weather. The results of this study are compared with those obtained by applying the ISO 15927-3:2009 standard, which is based on the semi-empirical analysis of hourly wind and Rainfall data. This study identifies the intrinsic dependence of the aforementioned synoptic method on the weather conditions that exist at each site, which affect the reliability and accuracy of the estimates. Thus, corrective changes that would enable the synoptic method to generate more reliable approximations are proposed, and a new optimised methodology is presented; the precision of the new method relies on synoptic observations but is independent of weather conditions. The results, validated at four Spanish sites, suggest that in the absence of hourly data for implementing the ISO standard, this optimised synoptic method is able to generate reasonably accurate estimates of the annual directional exposure to Driving Rain, regardless of the particular site conditions.
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Combined use of wind-driven Rain and wind pressure to define water penetration risk into building façades: The Spanish case
Building and Environment, 2013Co-Authors: José M. Pérez-bella, Javier Domínguez-hernández, Beatriz Rodríguez-soria, Juan J. Del Coz-díaz, Enrique Cano-suñénAbstract:Abstract This article defines a new index to characterise the risk of atmospheric water penetration into building enclosures. This risk index integrates the two most relevant exposure parameters for this phenomenon into a single value, combining the water supply presented by Driving Rain and simultaneous wind pressure on the surface of the enclosure. Compared with the usual wind-driven Rain exposure maps, the inclusion of Driving Rain wind pressure in this index permits a more complete assessment of the risk of penetration. Therefore, this index represents a powerful tool for defining more appropriate facade solutions for exposures that result in atmospheric water penetration. This risk index was calculated for 80 Spanish sites scattered around the Iberian Peninsula and the Canary and Balearic Islands using daily precipitation averages and wind speed averages for each location collected over 30 years. As a result, a risk index map has been produced for Spain. The risk characterisation obtained in this study enables an objective improvement of current Spanish building regulations governing the design of facades against the penetration of atmospheric water.
Javier Domínguez-hernández - One of the best experts on this subject based on the ideXlab platform.
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On the significance of the climate-dataset time resolution in characterising wind-driven Rain and simultaneous wind pressure. Part I: scalar approach
Stochastic Environmental Research and Risk Assessment, 2018Co-Authors: José M. Pérez-bella, Javier Domínguez-hernández, Enrique Cano-suñén, Juan J. Coz-díaz, Mar Alonso-martínezAbstract:The joint action of wind-driven Rain and wind pressure is the main cause of water penetration in building facades, which causes various habitability and durability problems. The most widespread characterisation of both climate factors is based on exposure indices calculated in free-field conditions from records of precipitation—wind speed (scalar indices), adding wind direction for directional indices. The time resolution of this climate dataset defines the calculation effort and the accuracy obtained, and average daily, monthly, or annual records are typical due to their greater availability. This paper investigates the influence of this time resolution on the accuracy of these scalar exposure indices (Driving Rain index, hereafter aDRI, and Driving-Rain wind pressure, hereafter DRWP) by assessing the nature and magnitude of errors associated with different averaged records. For this purpose, 10-min, hourly, daily, monthly and annual meteorological data collected over 15 years in 6 Spanish weather stations at locations characterised by different environments and topography are analysed. In addition, relationships capable of adjusting indices of any time resolution to an accuracy similar to that reached through 10-min records are proposed. In general, the value of Driving-Rain wind pressure exhibits greater sensitivity than the Driving Rain index at this time resolution, incorporating significant errors even with daily datasets. In turn, the use of monthly and annual records should be reconsidered, given their high uncertainty. The results demonstrate how the daily datasets for aDRI indices and hourly datasets for DRWP values are sufficient to characterise these exposures with errors of less than 11%.
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On the significance of the climate-dataset time resolution in characterising wind-driven Rain and simultaneous wind pressure. Part II: directional analysis
Stochastic Environmental Research and Risk Assessment, 2017Co-Authors: José M. Pérez-bella, Javier Domínguez-hernández, Juan J. Del Coz-díaz, Enrique Cano-suñén, Felipe Pedro Álvarez RabanalAbstract:Both semi-empirical methods and CFD simulations use real climate datasets as a basis for determining the building facade exposure to wind-driven Rain and simultaneous wind pressure. The time resolution of these datasets and the number of variables considered (commonly Rainfall intensity, wind speed and wind direction) determine the required calculation effort and the accuracy of the result. Omitting the wind direction, a former article (Part I of this research) has analysed the effect of this time resolution on two scalar exposure indices obtained by semi-empirical methods: Driving Rain index (aDRI) and Driving-Rain wind pressure (DRWP). However, the wind direction during precipitation events also causes significant exposure variations between possible facade orientations. Thus, it is also necessary to clarify the influence of the time resolution of the dataset, on the accuracy of the directional semi-empirical calculation of aDRI and DRWP. To meet this challenge, the article examines 10-min climate records collected between 2001 and 2016 at 6 Spanish locations, uses them to obtain hourly, daily, monthly and annual datasets, and analyses the accuracy of the directional exposure indices associated with each time resolution. The results show that a daily dataset would allow identifying the most exposed orientation with an error less than 45°. However, even the hourly datasets cause errors close to 10% in the exposure values identified on each facade orientation. Finally, adjustment relationships that allow estimating the maximum value of directional exposure from simple scalar indices are obtained.
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Assessment of water penetration risk in building facades throughout Brazil
Building Research & Information, 2016Co-Authors: Javier Domínguez-hernández, José M. Pérez-bella, Enrique Cano-suñén, Mar Alonso-martínez, J.j. Del Coz-díazAbstract:ABSTRACTThe penetration of atmospheric water (Rain) into facades creates problems for building habitability and the durability of construction materials. This study analyses the exposure of Brazilian facades to the two main climate factors responsible for this penetration: wind-driven Rain and Driving Rain wind pressure. Daily weather records (spanning 2005–14, from 171 weather stations) were analysed. Both exposure factors were combined to assess the risk of water penetration at each site. The relationships between the different exposure indices calculated from daily, monthly and annual records were determined and compared with results from other countries. From this analysis, detailed isopleth maps are provided that allow a graphical characterization of the moisture exposure conditions of facades anywhere in Brazil. A comprehensive characterization of the water penetration exposure in Brazilian enclosures is created and can be used to establish normative design requirements for actual climatic condition...
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Optimised method for estimating directional Driving Rain from synoptic observation data
Journal of Wind Engineering and Industrial Aerodynamics, 2013Co-Authors: José M. Pérez-bella, Javier Domínguez-hernández, Beatriz Rodríguez-soria, Juan J. Del Coz-díaz, Enrique Cano-suñénAbstract:In this article, the annual directional exposure to Driving Rain and its characteristics are analysed and discussed at four Spanish sites that are characterised by different Rainfall levels and topographical and wind conditions. For this study, the present weather observation method is used, which is based on average annual Rainfall data and synoptic observations of the present weather. The results of this study are compared with those obtained by applying the ISO 15927-3:2009 standard, which is based on the semi-empirical analysis of hourly wind and Rainfall data. This study identifies the intrinsic dependence of the aforementioned synoptic method on the weather conditions that exist at each site, which affect the reliability and accuracy of the estimates. Thus, corrective changes that would enable the synoptic method to generate more reliable approximations are proposed, and a new optimised methodology is presented; the precision of the new method relies on synoptic observations but is independent of weather conditions. The results, validated at four Spanish sites, suggest that in the absence of hourly data for implementing the ISO standard, this optimised synoptic method is able to generate reasonably accurate estimates of the annual directional exposure to Driving Rain, regardless of the particular site conditions.
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Combined use of wind-driven Rain and wind pressure to define water penetration risk into building façades: The Spanish case
Building and Environment, 2013Co-Authors: José M. Pérez-bella, Javier Domínguez-hernández, Beatriz Rodríguez-soria, Juan J. Del Coz-díaz, Enrique Cano-suñénAbstract:Abstract This article defines a new index to characterise the risk of atmospheric water penetration into building enclosures. This risk index integrates the two most relevant exposure parameters for this phenomenon into a single value, combining the water supply presented by Driving Rain and simultaneous wind pressure on the surface of the enclosure. Compared with the usual wind-driven Rain exposure maps, the inclusion of Driving Rain wind pressure in this index permits a more complete assessment of the risk of penetration. Therefore, this index represents a powerful tool for defining more appropriate facade solutions for exposures that result in atmospheric water penetration. This risk index was calculated for 80 Spanish sites scattered around the Iberian Peninsula and the Canary and Balearic Islands using daily precipitation averages and wind speed averages for each location collected over 30 years. As a result, a risk index map has been produced for Spain. The risk characterisation obtained in this study enables an objective improvement of current Spanish building regulations governing the design of facades against the penetration of atmospheric water.
Nil Sahal - One of the best experts on this subject based on the ideXlab platform.
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proposed method for calculating water penetration test parameters of wall assemblies as applied to istanbul turkey
Building and Environment, 2008Co-Authors: Nil Sahal, Marc-antoine LacasseAbstract:Abstract Water penetration of a building envelope assembly is typically assessed on the basis of the degree of watertightness (i.e. lack of water ingress) of the components of the assembly when subjected to simulated Driving Rain conditions. Test standards provide the magnitude and extent of these test conditions as suggested by the test parameters, i.e. the water spray rates and pressure differences and the dwell time over which these are to be applied. Such conditions would presume to simulate Driving Rain and wind conditions of locations spread over a broad geographical area. For example, the water spray rate suggested for use in watertightness performance tests in EN 12155—Curtain walling–watertightness–laboratory test under static pressure—is considered appropriate for simulating Driving Rain and wind conditions for locations across Europe. However, test parameters should be based on the expected Driving Rain intensities and wind pressures that are likely to occur for a specific climate and a given return period. It might also be based on the building type (e.g. high or low-rise building), or even on the location on the building facade. Hence, a method is required for calculating water penetration test parameters for specific buildings located in a specific climate. The purpose of this paper is to propose a method for calculating water penetration test parameters. A survey of existing methods is first provided that focuses on the quantification of Driving Rain on buildings and thereafter, calculation of water penetration test parameters. The merits and drawbacks of these methods are then discussed. Based on this review, a method for calculating test parameters is proposed and is applied to developing water penetration test parameters for Istanbul, Turkey. A comparison of test parameters calculated from the proposed method with those given in existing Turkish standards TS EN 12155–Curtain walling–watertightness–laboratory test under static pressure—and TS ENV 13050—Curtain walling–watertightness–laboratory test under dynamic condition of air pressure and water spray—related to Istanbul, indicated that the water spray rate given in the TS standards is higher than spray rates calculated from the proposed method for return periods of 5, 10 and 30 years.
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proposed approach for defining climate regions for turkey based on annual Driving Rain index and heating degree days for building envelope design
Building and Environment, 2006Co-Authors: Nil SahalAbstract:Abstract Field surveys in Turkey indicate that a significant number of exterior wall assemblies in various regions of the country suffer from moisture degradation. These cases reveal that designers are in need for a climate scheme of Turkey, which indicates regions that require special provisions to prevent moisture degradation. Hence, this paper presents an approach for defining climate regions for Turkey. Initially, annual Driving Rain index (aDRI) based on monthly data is calculated and a Driving Rain map of Turkey is produced. Then, population-weighted heating degree-days (PW HDD) zones of Turkey are presented. Based on the aDRI and PW HDD zones, three climate regions of Turkey are established. Region 1 represents sheltered locations, i.e. locations which have aDRI less than 3. Region 2 represents locations (aDRI between 3 and 6 and PW HDD
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water entry function of a hardboard siding clad wood stud wall
Building and Environment, 2005Co-Authors: Nil Sahal, M A LacasseAbstract:This paper presents derivation of a water entry function of a hardboard siding-clad wood stud wall assembly. Water entry function provides input data to heat, air and moisture simulation models to facilitate the prediction of the long-term water entry performance of the specific assembly. Initially, an experimental work was conducted in which the hardboard siding-clad wood stud wall specimen was subjected to simulated Driving Rain loads, i.e. spray rates and static pressure differential. The specimen included a dRainage cavity and specific deficiencies such as a missing length of sealant at the interface between the cladding and penetrating components, i.e. window, ventilation duct and electrical outlet. Water entering the deficiencies was collected at the dRainage and stud cavities just below the penetrating components. Water entry results provided information on water entry rates as functions of simulated Driving Rain loads, which in turn permitted the development of a water entry function of the assembly. Entry function is a basic relationship that relates the quantity of water entry in a certain location within the assembly to the simulated Driving Rain loads. Measured climatic data of a specific climate, i.e. Rainfall intensity and wind speed, was related to the simulated Driving Rain loads, and the entry function provided a means of estimating the water entry loads of the hardboard siding-clad wood stud wall assembly located in the specific climate.
