Pub Date : 2005-04-01DOI: 10.1177/1097196305051793
H. Schwab, U. Heinemann, Johannes Wachtel, H. Ebert, J. Fricke
The climatic conditions (temperature, relative humidity, and water vapor pressure) on both sides of vacuum insulation panels (VIPs) that were integrated into different building constructions are measured every hour. The influence of these conditions on the increase in air pressure and water content within the VIPs is estimated using a calculation model. The results of these model calculations are correlated with the pressure and mass measurements on VIPs, exposed to actual climate but removed for laboratory measurements. First, we find that upon use of the temperature-dependent air permeation rates for VIPs, the linear increase within the VIPs can be predicted reliably. Thus, it is sufficient to use annual average temperatures for these estimates. Second, the mass increase of VIPs due to infusion of water vapor through the barrier foil can be determined using the calculation model. The ‘driving’ force in this case is the difference in vapor pressure across the foil cover, which decreases with time, once the water vapor pressure within the VIP starts increasing. In effect, the water vapor pressure and the water content within the VIPs reach equilibrium. Depending on the climatic conditions, the maximum water content between 3 and 7 m% can be predicted.
{"title":"Predictions for the Increase in Pressure and Water Content of Vacuum Insulation Panels (VIPs) Integrated into Building Constructions using Model Calculations","authors":"H. Schwab, U. Heinemann, Johannes Wachtel, H. Ebert, J. Fricke","doi":"10.1177/1097196305051793","DOIUrl":"https://doi.org/10.1177/1097196305051793","url":null,"abstract":"The climatic conditions (temperature, relative humidity, and water vapor pressure) on both sides of vacuum insulation panels (VIPs) that were integrated into different building constructions are measured every hour. The influence of these conditions on the increase in air pressure and water content within the VIPs is estimated using a calculation model. The results of these model calculations are correlated with the pressure and mass measurements on VIPs, exposed to actual climate but removed for laboratory measurements. First, we find that upon use of the temperature-dependent air permeation rates for VIPs, the linear increase within the VIPs can be predicted reliably. Thus, it is sufficient to use annual average temperatures for these estimates. Second, the mass increase of VIPs due to infusion of water vapor through the barrier foil can be determined using the calculation model. The ‘driving’ force in this case is the difference in vapor pressure across the foil cover, which decreases with time, once the water vapor pressure within the VIP starts increasing. In effect, the water vapor pressure and the water content within the VIPs reach equilibrium. Depending on the climatic conditions, the maximum water content between 3 and 7 m% can be predicted.","PeriodicalId":435154,"journal":{"name":"Journal of Thermal Envelope and Building Science","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128174961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-04-01DOI: 10.1177/1097196305051791
H. Schwab, U. Heinemann, A. Beck, H. Ebert, J. Fricke
Vacuum insulation panels (VIPs) are distinguished by their outstandingly low thermal conductivity. In the evacuated state, the VIPs being examined in this study (which have fumed silica as a core material) have a thermal conductivity of 4 10 3 W/(m K). Gases (N2, O2, H2O,...), which penetrate the foil cover cause an increase in pressure and water content and hence, an increase in the thermal conductivity. To determine these increases, VIPs have been manufactured with laminated aluminum foils (AlF) and aluminum-coated multilayer foils (MFs). The pressure and mass increases are determined at various temperatures, humidity, and with various panel formats. Large differences in the rates of pressure increases (1 -70 mbar/yr) and in the rates of mass increases (0.02-4 mass%/yr) are recorded, depending on the foil type, climatic conditions, and panel formats. From these measurements, the air and vapor transmission rates of the foil covers and their dependence on temperature, relative humidity, and panel size are derived. Using these gas transmission rates, it is possible to estimate which pressure increases are to be expected for panel formats and climatic conditions occurring in building applications. With laminated Al foils and selected Al-coated multilayer foils, rates of pressure increases below 1-2 mbar/yr are achieved. The rates of mass increase for typical climatic conditions for laminated Al foils are significantly below 0.1 mass%/yr, while with Al-coated multilayer foils, depending on the foil quality, mass increases per time of up to 1 mass%/yr are recorded. Increases in gas pressure per time of 1 -2 mbar/yr lead to relatively small increases in thermal conductivity, allowing applications in the construction sector, where service lives of several decades are required. With respect to the humidity-related increase in thermal conductivity, one has to know the climatic conditions, which have a strong influence on the increase in mass, and, above all, the precise dependence of the thermal conductivity on the humidity in the VIP.
{"title":"Permeation of Different Gases Through Foils used as Envelopes for Vacuum Insulation Panels","authors":"H. Schwab, U. Heinemann, A. Beck, H. Ebert, J. Fricke","doi":"10.1177/1097196305051791","DOIUrl":"https://doi.org/10.1177/1097196305051791","url":null,"abstract":"Vacuum insulation panels (VIPs) are distinguished by their outstandingly low thermal conductivity. In the evacuated state, the VIPs being examined in this study (which have fumed silica as a core material) have a thermal conductivity of 4 10 3 W/(m K). Gases (N2, O2, H2O,...), which penetrate the foil cover cause an increase in pressure and water content and hence, an increase in the thermal conductivity. To determine these increases, VIPs have been manufactured with laminated aluminum foils (AlF) and aluminum-coated multilayer foils (MFs). The pressure and mass increases are determined at various temperatures, humidity, and with various panel formats. Large differences in the rates of pressure increases (1 -70 mbar/yr) and in the rates of mass increases (0.02-4 mass%/yr) are recorded, depending on the foil type, climatic conditions, and panel formats. From these measurements, the air and vapor transmission rates of the foil covers and their dependence on temperature, relative humidity, and panel size are derived. Using these gas transmission rates, it is possible to estimate which pressure increases are to be expected for panel formats and climatic conditions occurring in building applications. With laminated Al foils and selected Al-coated multilayer foils, rates of pressure increases below 1-2 mbar/yr are achieved. The rates of mass increase for typical climatic conditions for laminated Al foils are significantly below 0.1 mass%/yr, while with Al-coated multilayer foils, depending on the foil quality, mass increases per time of up to 1 mass%/yr are recorded. Increases in gas pressure per time of 1 -2 mbar/yr lead to relatively small increases in thermal conductivity, allowing applications in the construction sector, where service lives of several decades are required. With respect to the humidity-related increase in thermal conductivity, one has to know the climatic conditions, which have a strong influence on the increase in mass, and, above all, the precise dependence of the thermal conductivity on the humidity in the VIP.","PeriodicalId":435154,"journal":{"name":"Journal of Thermal Envelope and Building Science","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130995486","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-04-01DOI: 10.1177/1097196305051794
H. Schwab, C. Stark, Johannes Wachtel, H. Ebert, J. Fricke
In architecture, the outstandingly low thermal conductivity of vacuum insulation panels (VIPs) of 4 103 W/(m K) allows to realize thin thermal insulation layers. Typical U-values are 0.2 W/(m2 K) for a 2 cm-thick VIP. On the other hand, with vacuum-insulated faç ades the relative effect of thermal bridges is much stronger than that for conventionally insulated buildings. In this work, different thermal bridges are investigated. Especially with VIPs with laminated Al foils (here the aluminum foil is 8 mm thick and laminated on both sides with plastic foils of 15 mm PET and 50 mm PE), strong thermal bridges around the perimeter of the VIPs occur. Also the mounting system can have a strong negative effect on the thermal performance of VIP-insulated walls. As our calculations show, the effect of the thermal bridge depends strongly on the thermal contact of the VIPs with the wall. Therefore, it is necessary to optimize every vacuum-insulated construction in order to make the best use of the low thermal conductivity of VIPs. As an example, we describe how VIPs were effectively integrated into a renovated gable faç ade and into a new ultra-low energy timber building.
{"title":"Thermal Bridges in Vacuum-insulated Building Façades","authors":"H. Schwab, C. Stark, Johannes Wachtel, H. Ebert, J. Fricke","doi":"10.1177/1097196305051794","DOIUrl":"https://doi.org/10.1177/1097196305051794","url":null,"abstract":"In architecture, the outstandingly low thermal conductivity of vacuum insulation panels (VIPs) of 4 103 W/(m K) allows to realize thin thermal insulation layers. Typical U-values are 0.2 W/(m2 K) for a 2 cm-thick VIP. On the other hand, with vacuum-insulated faç ades the relative effect of thermal bridges is much stronger than that for conventionally insulated buildings. In this work, different thermal bridges are investigated. Especially with VIPs with laminated Al foils (here the aluminum foil is 8 mm thick and laminated on both sides with plastic foils of 15 mm PET and 50 mm PE), strong thermal bridges around the perimeter of the VIPs occur. Also the mounting system can have a strong negative effect on the thermal performance of VIP-insulated walls. As our calculations show, the effect of the thermal bridge depends strongly on the thermal contact of the VIPs with the wall. Therefore, it is necessary to optimize every vacuum-insulated construction in order to make the best use of the low thermal conductivity of VIPs. As an example, we describe how VIPs were effectively integrated into a renovated gable faç ade and into a new ultra-low energy timber building.","PeriodicalId":435154,"journal":{"name":"Journal of Thermal Envelope and Building Science","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125535569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-04-01DOI: 10.1177/1097196305051894
H. Schwab, U. Heinemann, A. Beck, H. Ebert, J. Fricke
For vacuum insulation panels (VIPs) with fumed silica kernels and foils as cover, a calculation model is developed to predict the service life. It is defined as the period during which the thermal conductivity of the VIP has risen 50% due to infusion of air and moisture. Two panel sizes, 50 ×50 × 1 cm3 and 100 × 100 × 2 cm3 are considered. For VIPs with laminated aluminum foils, calculated service lives of many decades are determined. For VIPs with aluminum-coated multilayer foils, shorter service lives still above 20 are calculated. This is due to the higher water vapor transmission through the Al-coated multilayer foils (compared to laminated Al foil) and the humidity-related increase in thermal conductivity. Overall, our model predicts service lives, which are large enough for applications of VIPs in buildings. An open question that remains is the long-term stability of the foil cover.
{"title":"Prediction of Service Life for Vacuum Insulation Panels with Fumed Silica Kernel and Foil Cover","authors":"H. Schwab, U. Heinemann, A. Beck, H. Ebert, J. Fricke","doi":"10.1177/1097196305051894","DOIUrl":"https://doi.org/10.1177/1097196305051894","url":null,"abstract":"For vacuum insulation panels (VIPs) with fumed silica kernels and foils as cover, a calculation model is developed to predict the service life. It is defined as the period during which the thermal conductivity of the VIP has risen 50% due to infusion of air and moisture. Two panel sizes, 50 ×50 × 1 cm3 and 100 × 100 × 2 cm3 are considered. For VIPs with laminated aluminum foils, calculated service lives of many decades are determined. For VIPs with aluminum-coated multilayer foils, shorter service lives still above 20 are calculated. This is due to the higher water vapor transmission through the Al-coated multilayer foils (compared to laminated Al foil) and the humidity-related increase in thermal conductivity. Overall, our model predicts service lives, which are large enough for applications of VIPs in buildings. An open question that remains is the long-term stability of the foil cover.","PeriodicalId":435154,"journal":{"name":"Journal of Thermal Envelope and Building Science","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126901612","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-04-01DOI: 10.1177/1097196305051792
H. Schwab, U. Heinemann, A. Beck, H. Ebert, J. Fricke
The influence of moisture in vacuum insulation panels (VIPs), with fumed silica kernels, on their thermal conductivity has been investigated. The VIPs are produced with different water contents. The thermal conductivities at different water contents are measured under stationary conditions in a hot-plate apparatus with an average temperature of 10°C (plate temperatures are 0 and 20°C). The increase in thermal conductivity is approximately proportional to the water content. The increase is ≈0.5 × 10 -3 W/(m K) per mass% of water. For typical middle European climate, a maximum moisture content of ≈6 mass% can be expected, which corresponds to a maximum increase of thermal conductivity of ≈3 × 10 -3 W/(m K) for VIPs with fumed silica kernels.
{"title":"Dependence of Thermal Conductivity on Water Content in Vacuum Insulation Panels with Fumed Silica Kernels","authors":"H. Schwab, U. Heinemann, A. Beck, H. Ebert, J. Fricke","doi":"10.1177/1097196305051792","DOIUrl":"https://doi.org/10.1177/1097196305051792","url":null,"abstract":"The influence of moisture in vacuum insulation panels (VIPs), with fumed silica kernels, on their thermal conductivity has been investigated. The VIPs are produced with different water contents. The thermal conductivities at different water contents are measured under stationary conditions in a hot-plate apparatus with an average temperature of 10°C (plate temperatures are 0 and 20°C). The increase in thermal conductivity is approximately proportional to the water content. The increase is ≈0.5 × 10 -3 W/(m K) per mass% of water. For typical middle European climate, a maximum moisture content of ≈6 mass% can be expected, which corresponds to a maximum increase of thermal conductivity of ≈3 × 10 -3 W/(m K) for VIPs with fumed silica kernels.","PeriodicalId":435154,"journal":{"name":"Journal of Thermal Envelope and Building Science","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129736300","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-01-01DOI: 10.1177/1097196305047003
Mark Bomberg, M. Pazera, R. Plagge
For isotropic materials with a significant fraction of micro-pores, the cumulative water intake per unit of inflow surface area typically yields a linear function of the square root of time elapse. The authors postulate that this dependence has a limited range of validity. The validity of this approximation starts from an initial period that is inversely proportional to the rate of water intake and ends much before the material reaches the capillary moisture content. Experimental investigation presented here uses a differential presentation of the cumulative water inflow and clearly indicates that material such as calcium silicate or brick belong to a broad class of materials characterized by a constant water absorption coefficient (A-coefficient). Initial period varies from ½ to 4 minutes. On the other hand, materials with a multiple pore-system such as an Aerated Autoclaved Concrete (AAC) may display a systematically varying A-coefficient. Authors propose a test procedure limited to 1-hour duration that can be used to derive a practical and reproducible value of A-coefficient.
{"title":"Analysis of Selected Water Absorption Coefficient Measurements","authors":"Mark Bomberg, M. Pazera, R. Plagge","doi":"10.1177/1097196305047003","DOIUrl":"https://doi.org/10.1177/1097196305047003","url":null,"abstract":"For isotropic materials with a significant fraction of micro-pores, the cumulative water intake per unit of inflow surface area typically yields a linear function of the square root of time elapse. The authors postulate that this dependence has a limited range of validity. The validity of this approximation starts from an initial period that is inversely proportional to the rate of water intake and ends much before the material reaches the capillary moisture content. Experimental investigation presented here uses a differential presentation of the cumulative water inflow and clearly indicates that material such as calcium silicate or brick belong to a broad class of materials characterized by a constant water absorption coefficient (A-coefficient). Initial period varies from ½ to 4 minutes. On the other hand, materials with a multiple pore-system such as an Aerated Autoclaved Concrete (AAC) may display a systematically varying A-coefficient. Authors propose a test procedure limited to 1-hour duration that can be used to derive a practical and reproducible value of A-coefficient.","PeriodicalId":435154,"journal":{"name":"Journal of Thermal Envelope and Building Science","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124627310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-01-01DOI: 10.1177/1097196305048628
C. Simonson, T. Ojanen, M. Salonvaara
Vapor-permeable building envelopes have received renewed interest because they can moderate indoor humidity levels and improve the drying of the envelope during summer condensation conditions. In this paper, the moisture performance of a vapor-permeable building envelope is presented with field measurements and numerical simulations. The results show that the diffusion resistance of the internal surface should be greater than that of the external surface (typically recommended ratio of 3: 1 or 5: 1), but that the vapor resistance of the vapor retarder can be significantly below that provided by polyethylene and still result in a safe structure, even in a cold climate.
{"title":"Moisture Performance of an Airtight, Vapor-permeable Building Envelope in a Cold Climate","authors":"C. Simonson, T. Ojanen, M. Salonvaara","doi":"10.1177/1097196305048628","DOIUrl":"https://doi.org/10.1177/1097196305048628","url":null,"abstract":"Vapor-permeable building envelopes have received renewed interest because they can moderate indoor humidity levels and improve the drying of the envelope during summer condensation conditions. In this paper, the moisture performance of a vapor-permeable building envelope is presented with field measurements and numerical simulations. The results show that the diffusion resistance of the internal surface should be greater than that of the external surface (typically recommended ratio of 3: 1 or 5: 1), but that the vapor resistance of the vapor retarder can be significantly below that provided by polyethylene and still result in a safe structure, even in a cold climate.","PeriodicalId":435154,"journal":{"name":"Journal of Thermal Envelope and Building Science","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121933830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-01-01DOI: 10.1177/1097196305048596
T. V. Rasmussen
This paper discusses the prediction of the density necessary for the prevention of the settling of hygroscopic and nonhygroscopic loose-fill insulation in walls, when the criteria for creep in granular materials are applied. The practical use of a theoretical framework presented earlier and the material characteristics used to develop an equation from which the necessary density can be predicted, are described. The empirical framework allows a quantitative approach to the problem of achieving nonsettling of a loose-fill insulation material in a given wall. The study involves the use of empirically derived equations to predict the density of a loose-fill insulation material required to ensure volume stability in a wall exposed to one type of cyclical humidity conditions. An empirical model for predicting the creep of materials has been developed in earlier papers. The creep was determined from the corresponding tests. The use of the method is demonstrated by showing the results from a full-scale wall test. The method is applied for different cavity sizes together with the associated characteristics of four hygroscopic and one nonhygroscopic loose-fill insulation materials exposed to the same climatic conditions. In addition, it is shown that for many repeated cyclical humidity conditions, the creep of the hygroscopic and nonhygroscopic loose-fill insulation materials asymptotically approached equilibrium.
{"title":"Prediction of Density for Prevention of Settling of Hygroscopic and Nonhygroscopic Loose-fill Insulation in Walls","authors":"T. V. Rasmussen","doi":"10.1177/1097196305048596","DOIUrl":"https://doi.org/10.1177/1097196305048596","url":null,"abstract":"This paper discusses the prediction of the density necessary for the prevention of the settling of hygroscopic and nonhygroscopic loose-fill insulation in walls, when the criteria for creep in granular materials are applied. The practical use of a theoretical framework presented earlier and the material characteristics used to develop an equation from which the necessary density can be predicted, are described. The empirical framework allows a quantitative approach to the problem of achieving nonsettling of a loose-fill insulation material in a given wall. The study involves the use of empirically derived equations to predict the density of a loose-fill insulation material required to ensure volume stability in a wall exposed to one type of cyclical humidity conditions. An empirical model for predicting the creep of materials has been developed in earlier papers. The creep was determined from the corresponding tests. The use of the method is demonstrated by showing the results from a full-scale wall test. The method is applied for different cavity sizes together with the associated characteristics of four hygroscopic and one nonhygroscopic loose-fill insulation materials exposed to the same climatic conditions. In addition, it is shown that for many repeated cyclical humidity conditions, the creep of the hygroscopic and nonhygroscopic loose-fill insulation materials asymptotically approached equilibrium.","PeriodicalId":435154,"journal":{"name":"Journal of Thermal Envelope and Building Science","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129876882","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-01-01DOI: 10.1177/1097196305048597
D. Derome
The hygrothermal performance of assemblies can be assessed by testing and monitoring large-scale specimens exposed to realistic conditions under controlled laboratory settings. Moisture transfer cannot be measured directly, but moisture content can be monitored. A large-scale test of two flat roof assemblies filled with cellulose insulation is performed. The six-and-a-half-month test simulated a complete wetting and drying cycle from winter to summer. The wood structure and the cellulose insulation are the object of an extensive moisture content monitoring which included 102 resistance-type electronic moisture probes and 120 gravimetric specimens. The objective of this paper is to report on the changes in moisture content in the cellulose insulation as a function of the different air leakage paths.
{"title":"Moisture Accumulation in Cellulose Insulation Caused by Air Leakage in Flat Wood Frame Roofs","authors":"D. Derome","doi":"10.1177/1097196305048597","DOIUrl":"https://doi.org/10.1177/1097196305048597","url":null,"abstract":"The hygrothermal performance of assemblies can be assessed by testing and monitoring large-scale specimens exposed to realistic conditions under controlled laboratory settings. Moisture transfer cannot be measured directly, but moisture content can be monitored. A large-scale test of two flat roof assemblies filled with cellulose insulation is performed. The six-and-a-half-month test simulated a complete wetting and drying cycle from winter to summer. The wood structure and the cellulose insulation are the object of an extensive moisture content monitoring which included 102 resistance-type electronic moisture probes and 120 gravimetric specimens. The objective of this paper is to report on the changes in moisture content in the cellulose insulation as a function of the different air leakage paths.","PeriodicalId":435154,"journal":{"name":"Journal of Thermal Envelope and Building Science","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127382499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2000-07-01DOI: 10.1177/109719630002400101
N FIRST EXAMINATION, a person would never guess how important civility is to human affairs. One dictionary writes it off as mere good manners. Another says that the word refers especially to cold and formal politeness. Yet another suggests that it is little more than acting in a way that is not outrightly rude. By these standards, one might conclude that civility is best exemplified by the polished hypocrisy of a diplomat in an unfriendly capital or the supercilious cor-
{"title":"The Duty of Civility","authors":"","doi":"10.1177/109719630002400101","DOIUrl":"https://doi.org/10.1177/109719630002400101","url":null,"abstract":"N FIRST EXAMINATION, a person would never guess how important civility is to human affairs. One dictionary writes it off as mere good manners. Another says that the word refers especially to cold and formal politeness. Yet another suggests that it is little more than acting in a way that is not outrightly rude. By these standards, one might conclude that civility is best exemplified by the polished hypocrisy of a diplomat in an unfriendly capital or the supercilious cor-","PeriodicalId":435154,"journal":{"name":"Journal of Thermal Envelope and Building Science","volume":"103 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122416890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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