Air Leakage (AL)
Heat loss and gain occur by infiltration through
cracks in the window assembly. It is indicated by an air leakage rating
(AL) expressed as the equivalent cubic feet of air passing through a
square foot of window area. The lower the AL, the less air will pass
through cracks in the window assembly. At this time, the AL is optional.
Select windows with an AL of 0.30 or less (units are cfm/sq ft).
U-Factor | Solar Heat Gain Coefficient | Visible Transmittance | Air Leakage
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