ABSTRACT
Energy travels in and out of a building through the walls and windows by means of conduction, convection, and radiation. The walls and windows, complex systems in themselves, are part of the overall building system. A wall system is composed of multiple layers that work in concert to provide shelter from the exterior weather. Wall systems vary in the degree to which they provide thermal resistance, moisture resistance, durability, and thermal storage. High-tech windows are now available, which can resist radiation heat transfer while still providing light and visibility. The combination of walls and windows within the building system can be adapted to meet a wide range of environmental conditions, recognizing that the best building envelope system for one climate may not be the first choice for another location.
