ABSTRACT
This chapter focuses on the solar radiation transmitted through windows. The building envelope has become increasingly detached from the building structure and floor plates, such that fenestration can be conceived of as an autonomous building system, which, among other things, manages solar gain. Building envelopes have increasingly included screens and shading devices to manage sunlight. Radiation relevant to buildings takes either the form of short-wave solar radiation or long-wave thermal radiation. Radiation is the transfer of heat or energy by electromagnetic waves. The chapter examines how that radiation affects occupants inside the building. The albedo or reflectance of a space is a function of its interior surface area, reflectivity of interior surfaces, glazing area, and glazing properties. Absorptance is the inverse of albedo, describing the ratio of radiation absorbed by a surface or volume. By casting shadows and measuring the exposed area, one can readily determine how much of the window is exposed to beam radiation at a particular time.
