Influence of materials’hygric properties on the hygrothermal performance of internal thermal insulation composite systems

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.

Indoor decorating and refurbishing materials and furniture volatile organic compounds emission labeling systems:A review

The volatile organic compounds (VOC) emitted from indoor decorating and refurbishing materials and furniture is recognized as one of the main causes of bad indoor air quality,which has resulted in serious economic losses.In European countries and the U.S.,labeling systems for indoor decorating and refurbishing materials and furniture were established to address this issue with good effect.This paper is a review of these existing labeling systems.The basic principle of the labeling systems is introduced.The technical,policy and operational parts of the labeling systems are then discussed.The research concentrates on target pollutants,their threshold values and the testing methods employed.Some problems were uncovered in these labeling systems:too many VOCs were targeted;the method to determine the threshold values was not very rigorous;the testing time was too long (7-28 d).Some China's special features in developing such system are stated.Therefore,as the world's largest national producer and consumer of wood based panels and furniture,China should learn from foreign experience of establishing labeling systems as much as it can.However China should not simply copy the foreign approaches but develop its own scientific labeling system for indoor decorating and refurbishing materials and furniture.

室外风环境视角下的高层住宅项目规划指标研究（英文）

目的：确定建筑容积率、建筑密度和建筑层数之间的关系,并将其作为主要的规划指标,研究其对室外风环境的影响。创新点：在以高层、高密度为特点的城市建设中,一个地块的用地规划指标可直接影响居住区的室外物理环境质量。一个高层建筑群的规划设计不应该只关注建筑物,还应考虑室外物理环境的品质。本研究从室外风环境角度出发,对13种＂容积率-建筑密度-建筑层数＂指标组合形成的高层建筑群布局进行对比,从而得到可直接服务于城市建设项目的规划策略。方法：1.通过确定建筑容积率、建筑密度和建筑层数之间的关系,建立三维高层建筑群布局模型,列出19种可能的指标组合（图2）;2.通过日照模拟分析工具Tarch和建筑消防间距计算筛选出13种符合当前规划要求的指标组合;3.运用风环境模拟软件Phoenics,对13种指标组合形成的高层建筑群布局进行风环境模拟运算;利用图形分析软件Photoshop CS,计算出舒适风面积比值,并进行相互对比（图3和4）;4.根据土建造价对不同建筑群布局的总造价进行对比（图6）。结论：在规划设计中,通常认为较低的容积率和较低的建筑高度意味着建筑体量较小,室外物理环境会更好。但是,本研究发现建筑层数越多、建筑高度越高,行人高度的室外舒适风区面积越大。不过,建筑层数从25层升到30层,舒适风区面积增加有限。加之考虑层数越高导致造价越高的因素,当面对容积率为2.0~4.0的高层地块时,不能简单地认为建筑层数最高的规划方案就是最好的方案。