A 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 appearances but is characterized by narrowly spaced vertical and horizontal caps with glass or metal infill panels. These systems provide a finished exterior appearance and most often a semi-finished interior as well. This system is basically designed to accommodate structural deflections, control wind-driven rain and air leakage, minimize the effect of solar radiation and provide for maintenance-free long-term performance.