This study presents the thermal comfort and hygrothermal performance of building envelope of the first certified passive single-family detached house in Estonia.Temperature and humidity conditions were measured from d...This study presents the thermal comfort and hygrothermal performance of building envelope of the first certified passive single-family detached house in Estonia.Temperature and humidity conditions were measured from different rooms and building envelopes.This article presents analysis of measurement results during the first year after construction.Results showed high room temperature,achieved mainly due to large windows with southern exposure and the small heat loss of the building envelope.High indoor temperature decreased the indoor RH(relative humidity)to quite low levels.Even the RH was low,the moisture excess was high indicating that the design of PH(passive houses)indoor humidity loads cannot be decreased.Humidity in the externally insulated cross-laminated timber panels was observed to be high,caused by drying out of the constructional moisture and the high diffusion resistance of the wood fibre sheathing board.That caused water vapour condensation and risk for mould growth.In conclusion,while planning buildings with high-energy efficiency,more focused attention should be paid to the performance of the building service systems and moisture safety already in the preliminary stages of design.展开更多
Internal thermal insulation composite system(ITICS)can be an important measure for the energy-saving retrofitting of buildings.However,ITICS may cause harmful effects on the hygrothermal performance of building envelo...Internal thermal insulation composite system(ITICS)can be an important measure for the energy-saving retrofitting of buildings.However,ITICS may cause harmful effects on the hygrothermal performance of building envelopes.This work investigated the influence of the materials’hygric properties on the hygrothermal perfor-mance of a typical ITICS in different climate conditions in China.Two base wall materials,the traditional concrete and a new type aerated concrete,were tested and compared for their hygric properties firstly.The influence of the hygroscopicity of exterior plasters,the permeability of insulation materials and the climate conditions were then analyzed with WUFI simulations.The hygrothermal performance was evaluated with consideration of the total water content(TWC)of the walls and the moisture flux strength,the relative humidity(RH)and the mould growth risk at the interface between the base wall and the insulation layer(B-I interface).The numerical analysis implies that the TWC of internal insulated walls depends mainly on the hygroscopicity of exterior plaster and the wind-driven rain intensity.The upper limits for the water absorption coefficient of exterior plasters used in Bei-jing,Shanghai and Fuzhou are 1e-9,1e-10,1e-10 m^(2)/s respectively.When such limits are guaranteed,a vapour tight system created by using insulation materials with a large vapour resistance factor or adding a vapour barrier can improve the hygrothermal performance of ITICS,especially for concrete walls in cold climate.展开更多
Uncertainty exists in many aspects of building simulation.A deterministic hygrothermal analysis may not sufficiently give a reliable guidance if a number of input variables are subject to uncertainty.In this paper,a p...Uncertainty exists in many aspects of building simulation.A deterministic hygrothermal analysis may not sufficiently give a reliable guidance if a number of input variables are subject to uncertainty.In this paper,a probabilistic-based method was developed to evaluate the hygrothermal performance of building components.The approach accounts for the uncertainties from model inputs and propagates them to the outputs through the simulation model,thus it provides a likelihood of performance risk.Latin hypercube sampling technique,incorporated with correlation structure among the inputs,was applied to generate the random samples that follows the intrinsic relations.The performance of an internally insulated masonry wall was evaluated by applying the proposed approach against different criteria.Thermal performance,condensation and mould growth potential of the renovated wall can overall satisfy the requirements stipulated in multifold standards.The most influential inputs were identified by the standardized regression sensitivity analysis and partial correlation technique.Both methods deliver the same key parameters for the single and time-dependent output variables in the case study.The probabilistic method can provide a comprehensive risk analysis and support the decision-maker and engineer in the design and optimization of building components.展开更多
Dynamic environmental testing is an effective means to study the energy and long-term hygrothermal performance of building enclosures. Southeast University is designing and building a large-scale dynamic environment s...Dynamic environmental testing is an effective means to study the energy and long-term hygrothermal performance of building enclosures. Southeast University is designing and building a large-scale dynamic environment simulation testing facility. It can simuhaneously and dynamically simulate temperature, relative humidity, infrared solar radiation, UV radiation, and precipitation. A transformation is needed to predict the energy and long-term hygrothermal performance of building enclosures under real service conditions using data obtained from accelerated tests.展开更多
Phase Change Materials(PCMs)have high thermal inertia,and hemp concrete(HC),a bio-based concrete,has strong hygroscopic behavior.In previous studies,PCM has been extensively combined with many materials,however,most o...Phase Change Materials(PCMs)have high thermal inertia,and hemp concrete(HC),a bio-based concrete,has strong hygroscopic behavior.In previous studies,PCM has been extensively combined with many materials,however,most of these studies focused on thermal properties while neglecting hygroscopic aspects.In this study,the two materials have been combined into a building envelope and the related hygrothermal properties have been studied.In particular,numerical studies have been performed to investigate the temperature and relative humidity behavior inside the HC,and the effect of adding PCM on the hygrothermal behavior of the HC.The results show that there is a high coupling between temperature and relative humidity inside the HC,since the relative humidity changes on the second and third days are different,with values of 8%and 4%,respectively.Also,the variation of relative humidity with temperature indicates the dominant influence of temperature on relative humidity variation.With the presence of PCM,the temperature variation inside the HC is damped due to the high thermal inertia of the PCM,which also leads to suppression of moisture evaporation and thus damping of relative humidity variation.On the second and third days,the temperature changes at the central position are reduced by 4.6%and 5.1%,compared to the quarter position.For the relative humidity change,the reductions are 5.3%and 5.4%on the second and third days,respectively.Therefore,PCM,with high thermal inertia,acts as a temperature damper and has the potential to increase the moisture buffering capacity inside the HC.This makes it possible for such a combined envelope to have both thermal and hygric inertia.展开更多
对甲壳素纤维在不同水浴温度和时间下进行热湿处理,应用DZF-6050型真空干燥箱、YG001A单纤维电子强力仪、KYKY-2800型扫描式电子纤维镜及D8DISCOVER with GADDS型X光衍射仪等对其热湿性能进行测试,并对测试结果进行分析.结果表明:在不...对甲壳素纤维在不同水浴温度和时间下进行热湿处理,应用DZF-6050型真空干燥箱、YG001A单纤维电子强力仪、KYKY-2800型扫描式电子纤维镜及D8DISCOVER with GADDS型X光衍射仪等对其热湿性能进行测试,并对测试结果进行分析.结果表明:在不同的水浴温度下,当水浴时间为80min时,纤维的断裂强力最高;在不同的水浴时间下,水浴温度为60℃时纤维的断裂强力最高;而纤维的断裂伸长随水浴时间及温度的变化不明显.因此,在对甲壳素纤维的后续处理中,选择水浴温度为60℃和水浴时间为80min时,可保证甲壳素纤维具有较大的断裂强力.展开更多
基金supported by the European Union through the European Regional Development Fundthe“Reducing the Environmental Impact of Buildings through Improvements of Energy Performance,AR12059”(financed by SA Archimedes)IUT1-15 project“Nearly-Zero Energy Solutions and Their Implementation on Deep Renovation of Buildings”(financed by the Estonian Research Council).
文摘This study presents the thermal comfort and hygrothermal performance of building envelope of the first certified passive single-family detached house in Estonia.Temperature and humidity conditions were measured from different rooms and building envelopes.This article presents analysis of measurement results during the first year after construction.Results showed high room temperature,achieved mainly due to large windows with southern exposure and the small heat loss of the building envelope.High indoor temperature decreased the indoor RH(relative humidity)to quite low levels.Even the RH was low,the moisture excess was high indicating that the design of PH(passive houses)indoor humidity loads cannot be decreased.Humidity in the externally insulated cross-laminated timber panels was observed to be high,caused by drying out of the constructional moisture and the high diffusion resistance of the wood fibre sheathing board.That caused water vapour condensation and risk for mould growth.In conclusion,while planning buildings with high-energy efficiency,more focused attention should be paid to the performance of the building service systems and moisture safety already in the preliminary stages of design.
基金Project supported by the National Natural Science Foundation of China(No.51805538)the Young Talent Fund of University Association for Science and Technology in Shaanxi Province,China(No.20190410)
基金This research was funded by National Key R&D Program of China(2017YFC0702800),which is gratefully acknowledged.
文摘Internal thermal insulation composite system(ITICS)can be an important measure for the energy-saving retrofitting of buildings.However,ITICS may cause harmful effects on the hygrothermal performance of building envelopes.This work investigated the influence of the materials’hygric properties on the hygrothermal perfor-mance of a typical ITICS in different climate conditions in China.Two base wall materials,the traditional concrete and a new type aerated concrete,were tested and compared for their hygric properties firstly.The influence of the hygroscopicity of exterior plasters,the permeability of insulation materials and the climate conditions were then analyzed with WUFI simulations.The hygrothermal performance was evaluated with consideration of the total water content(TWC)of the walls and the moisture flux strength,the relative humidity(RH)and the mould growth risk at the interface between the base wall and the insulation layer(B-I interface).The numerical analysis implies that the TWC of internal insulated walls depends mainly on the hygroscopicity of exterior plaster and the wind-driven rain intensity.The upper limits for the water absorption coefficient of exterior plasters used in Bei-jing,Shanghai and Fuzhou are 1e-9,1e-10,1e-10 m^(2)/s respectively.When such limits are guaranteed,a vapour tight system created by using insulation materials with a large vapour resistance factor or adding a vapour barrier can improve the hygrothermal performance of ITICS,especially for concrete walls in cold climate.
基金This study is financially supported by the Programme of Introducing Talents of Discipline to Universities,project No.B13011.
文摘Uncertainty exists in many aspects of building simulation.A deterministic hygrothermal analysis may not sufficiently give a reliable guidance if a number of input variables are subject to uncertainty.In this paper,a probabilistic-based method was developed to evaluate the hygrothermal performance of building components.The approach accounts for the uncertainties from model inputs and propagates them to the outputs through the simulation model,thus it provides a likelihood of performance risk.Latin hypercube sampling technique,incorporated with correlation structure among the inputs,was applied to generate the random samples that follows the intrinsic relations.The performance of an internally insulated masonry wall was evaluated by applying the proposed approach against different criteria.Thermal performance,condensation and mould growth potential of the renovated wall can overall satisfy the requirements stipulated in multifold standards.The most influential inputs were identified by the standardized regression sensitivity analysis and partial correlation technique.Both methods deliver the same key parameters for the single and time-dependent output variables in the case study.The probabilistic method can provide a comprehensive risk analysis and support the decision-maker and engineer in the design and optimization of building components.
基金supported by the Ministry of Science and Technology of China(2006BAJ04A01 and 2006BAJ03A04-01)
文摘Dynamic environmental testing is an effective means to study the energy and long-term hygrothermal performance of building enclosures. Southeast University is designing and building a large-scale dynamic environment simulation testing facility. It can simuhaneously and dynamically simulate temperature, relative humidity, infrared solar radiation, UV radiation, and precipitation. A transformation is needed to predict the energy and long-term hygrothermal performance of building enclosures under real service conditions using data obtained from accelerated tests.
基金We thank to the China Scholarship Council(CSC)for its financial support to the first author,No.201808120084.
文摘Phase Change Materials(PCMs)have high thermal inertia,and hemp concrete(HC),a bio-based concrete,has strong hygroscopic behavior.In previous studies,PCM has been extensively combined with many materials,however,most of these studies focused on thermal properties while neglecting hygroscopic aspects.In this study,the two materials have been combined into a building envelope and the related hygrothermal properties have been studied.In particular,numerical studies have been performed to investigate the temperature and relative humidity behavior inside the HC,and the effect of adding PCM on the hygrothermal behavior of the HC.The results show that there is a high coupling between temperature and relative humidity inside the HC,since the relative humidity changes on the second and third days are different,with values of 8%and 4%,respectively.Also,the variation of relative humidity with temperature indicates the dominant influence of temperature on relative humidity variation.With the presence of PCM,the temperature variation inside the HC is damped due to the high thermal inertia of the PCM,which also leads to suppression of moisture evaporation and thus damping of relative humidity variation.On the second and third days,the temperature changes at the central position are reduced by 4.6%and 5.1%,compared to the quarter position.For the relative humidity change,the reductions are 5.3%and 5.4%on the second and third days,respectively.Therefore,PCM,with high thermal inertia,acts as a temperature damper and has the potential to increase the moisture buffering capacity inside the HC.This makes it possible for such a combined envelope to have both thermal and hygric inertia.
文摘对甲壳素纤维在不同水浴温度和时间下进行热湿处理,应用DZF-6050型真空干燥箱、YG001A单纤维电子强力仪、KYKY-2800型扫描式电子纤维镜及D8DISCOVER with GADDS型X光衍射仪等对其热湿性能进行测试,并对测试结果进行分析.结果表明:在不同的水浴温度下,当水浴时间为80min时,纤维的断裂强力最高;在不同的水浴时间下,水浴温度为60℃时纤维的断裂强力最高;而纤维的断裂伸长随水浴时间及温度的变化不明显.因此,在对甲壳素纤维的后续处理中,选择水浴温度为60℃和水浴时间为80min时,可保证甲壳素纤维具有较大的断裂强力.
