The uncontrolled flow of air through a building envelope or a component of a building envelope as a result of a pressure difference. Air leakage can occur as infiltration, the uncontrolled movement of outdoor air into a building through intentional and unintentional openings in the building envelope, or as exfiltration, the uncontrolled movement o [..]

Sometimes called "air infiltration," a window's air-leakage performance rating gives buyers a sense of how impermeable a given window is to air leaks, both from the inside out and from [..]

The uncontrolled infiltration or exfiltration of air into buildings through cracks and joints in any building section, and around windows and doors of a building, caused by temperature or pressure dif [..]