Air Infiltration In Buildings

Since the 1973 embargo by the oil producing and exporting countries (OPEC), this nation has been aware of the need to save energy. Many sectors of the economy, notably transportation, have been critically studied, but until recently, one of the largest sectors — the buildings sector — has been virtually neglected. In the last few years, researchers have recognized that infiltration (the flow of air though leaks in the building envelope) is a critical factor in energy loss in buildings and merits concentrated research effort if national energy conservation goals are to be served. It has been established, for example, that the energy loss due to infiltration is between 6 percent and 9 percent of the total energy budget for the nation. This paper presents a physical model of infiltration in buildings that can be used to predict the infiltration for a wide range of construction types and climate regions. The the problems associated with commonly used tracer gas methods for measuring infiltration were examined in detail so that results obtained from the model could be properly compared with actual measurements. In addition, a simple model of the hydrodynamics of typical leaks in the building envelope was devised in order to study the physical processes of infiltration