Methods of calculating the rate of air infiltration into the building for the use of HVAC and building energy calculations

The uncontrolled flow of air from outside into the building through cracks and pores of the building happens, say air infiltration. Air infiltration into the building in several viewpoints, such as energy consumption, HVAC systems design, thermal comfort, indoor air quality and pollution and humidity is very important. According to many studies that have been conducted, air infiltration the reason 15 to 30 percent of and energy consumption and the heat load of the building, indicating the necessity of research on the subject. In general, three operating wind pressure, stack effect and HVAC systems has caused air infiltration in buildings, the impact of all three factors must be considered in the calculations. From the viewpoint of HVAC, the main issue is how to calculate the rate of air infiltration in the building. Heretofore several related analytical and experimental and standard tests for air infiltration rate of the different components of the building are presented. In this paper, some of the relations and equations presented in this issue have been studied. Finally the power low equation because of the accuracy and more applied to recent research, for calculating the rate of air infiltration in buildings is recommended.