Curtain wall system is a lightweight exterior cladding which is hung on the building structure usually from floor to floor.It can provide a variety of exterior apprearances but is characterized by narrowly spaced vertical and horizontal caps with glass or metalinfil panels.These systems provide a finished exterior apprearance and most often a semifinished interior as well.They are also designed to accommodate structural deflection,control wind-driven rain and air leakage,minimized the effects of solar radiation and provide for maintenance-free long term performance.

Most of today’s metal curtain wall system are constructed of light weight aluminum,although some may be of steel and glass.Since curtain wall system are a good example of building science principles applied to wall design,it may be useful to review some basic principles through the details of a typical curtain wall system.