Air infiltration through steel framed windows

Describes laboratory test performed on four steel swing windows and one steel double-hung window to determine leakage rates at different values of pressure and humidity. Concludes there is a wide variation in leakage rates of well constructed windows. Test results depend on the method of closing and latching windows, leakage for steel swing windows is found to differ when determined with ascending and descending pressure differences because the window is closed more tightly after completion of the ascending pressure difference. Test results on felt weatherstripped windows vary widely with air humidity with a 140% increase in leakage for dry as compared with saturated air.