建筑采光和遮阳课件

,Click to edit Master title style,Click to edit Master text styles,Second level,Author,*,BBRT,2011 05/31,Click to edit Master title style,Click to edit Master text styles,Second level,Author,建筑遮阳和日光照明,Building shading and daylighting control,许鹏 教授 博士 博导,机械工程学院,Peng Xu Professor,PhD,PE,MBA,College of Mechanical Engineering,建筑遮阳和日光照明Building shading an,Contents,内容纲要,Importance of shading control and daylighting,遮阳和自然采光的重要性,Shading strategies,常见遮阳策略,Day lighting and building envelope,日光照明与建筑立面,Sample projects and successful stories,成功案例,Software,计算软件,Contents内容纲要,1,2,Windows,architecture love them,occupants love them.They are modern,stylish,provide better view,easy to build,easy to maintain,What is the pain?,Public buildings,Office,Residential,Small commercials,2Windows,architecture love th,2,3,But engineers hate them,regulators do not want them,because they are wasting energy,What is the pain?,Building codes all over the world are using description or energy budget method to regulate the window to wall ratio,In summer,direct solar heat gain accounts for more than 50%of cooling load,In winter,wall insulation value is about 10 times higher than that of conventional windows.Therefore,buildings in cold climate can only have small windows,3But engineers hate them,regu,3,Windows are more important than any other building components in term of energy impact,In cold climate,more than 50%heat loss are through windows,In hot climate,direct solar heat gain is about 1/3 of cooling load,Lighting energy consumption is more than heating and cooling combined in commercial buildings,Low-energy intensity design and windows,Windows are more important tha,4,Low-energy intensity design and windows,Air conditioning peak load analysis in summer,50%of building envelope load are caused by windows,Window shading in summer and window insulation in winter are two critical issues,Low-energy intensity design an,5,Year of Built,Government office building built at different years,Energy survey results,Year of built,Shang-hai,Wuhan,Shen-zhen,Fuzhou,Chongqing,Total,Average Annual Electricity Use(kWh/m,2,）,1950,40.9,73.2,57.1,1970s or before,73.8,65.8,72.7,1980-1990s,125.4,67.5,67.5,70.7,2000s,138.2,66.8,53.7,66.2,Unknown,62.8,59.5,61.1,All,135.0,62.8,59.5,68.0,58.6,66.3,Maximum Annual Electricity Use(kWh/m,2,）,1950,52.6,78.2,78.2,1970s or before,138.4,87.1,138.4,1980-1990s,125.4,128.4,95.7,128.4,2000s,205.0,248.2,121.5,248.2,Unknown,73.4,105.0,105.0,All,205.0,73.4,105.0,248.2,121.5,248.2,Minimum Annual Electricity Use(kWh/m,2,）,1950,29.2,68.2,29.2,1970s or before,15.7,44.5,15.7,1980-1990s,125.4,21.4,42.0,21.4,2000s,104.7,19.2,5.1,5.1,Unknown,47.3,30.0,30.0,All,104.7,47.3,30.0,15.7,5.1,5.1,Sample size,1950,2,2,4,1970s or before,13,2,15,1980-1990s,1,12,5,18,2000s,3,14,18,35,Unknown,12,13,25,All,4,12,13,41,27,97,Year of Built,Government offi,6,Worst energy intensity buildings get worse and worse,Energy survey results,Worst energy intensity buildi,7,Background,Misunderstanding of windows,The smaller the better,control Window to Wall Ratio,East and West facades are same,Small north facing windows,Size matters,height does not,Window is fixed,Blinds are interior design jobs,nothing to do with energy,Low energy intensity buildings,Mis-concept today,BackgroundMisunderstanding of,8,Contents,内容纲要,Importance of shading control and daylighting,遮阳和自然采光的重要性,Shading strategies,常见遮阳策略,Day lighting and building envelope,日光照明与建筑立面,Sample projects and successful stories,成功案例,Contents内容纲要,9,The major flux is direct solar beam in summer,In winter,heat loss is the biggest problem,Second transfer is important,Tint glass is not very useful,Heat flux through the window,The major flux is direct solar,10,Window and shading design principles,Use exterior shading,or shading in between glasses,internal shading is useless,Design the building to shade itself,Use a horizontal form for south windows,Maximizing windows in north,Recessed windows,somewhat useful on the east,Use a vertical form on east and west windows.,Give west and south windows shading priority.East is not important,The shades color modifies light and heat.,Movable shading is better than fixed shade.Use movable devices if budget is allowed,Window and shading design prin,11,West shading is hardest,vertical louvers sometimes not working,Ways to reduce overhang size,West shading is hardest,verti,12,建筑采光和遮阳课件,13,Reducing the size of overhang furthermore,Allow lighting to come in,Reducing the size of overhang,14,Design shading for glare relief as well.Use,exterior shading to reduce glare by partially,blocking occupants view of the too-bright sky.,Design shading for glare relie,15,Dirt accumulation on blades,negative effects on building appearance,Poor reliability.Actuators and mechanical systems are prone to failure due to exposure to wind,sun and rain.,Difficult to repair.,Visually unattractive.,To avoid glare,blades are typically shut off in winter and useful solar heat is blocked too,From thermal point of view,ex