GLASS PERFORMANCE CHART
|Code||Description||U-Value||R-Value||Solar Heat Gain||Visible Light Transmittance|
|Clear||Dual||Dual pane, clear glass, no coatings||0.480||2.084||0.760||81%|
|Clear||Tri||Triple pane, clear glass, no coatings||0.310||3.226||0.685||74%|
|LOW-E||HS1-C180||Dual pane, one Low-E coating, Argon||0.260||3.846||0.685||79%|
|LOW-E||HS2-C180||Triple pane, one Low-E coating, Argon||0.184||5.433||0.615||73%|
|LOW-E||HS3-C180||Triple pane, two Low-E coatings, Argon||0.133||7.521||0.560||70%|
|SUNSTOP||HS4-C270||Dual pane, one SunStop coating, Argon||0.248||4.033||0.367||70%|
|SUNSTOP||HS5-C270||Triple pane, one SunStop coating, Argon||0.186||5.377||0.338||63|
|SUNSTOP||HS6-C270||Triple pane, two SunStop coating, Argon||0.124||8.065||0.310||54|
Values are in METRIC. All performance for C.O.G. (centre of glass) ratings are based on Vision v4.0 simulations. All C.O.G U- and R-values are based on ASHREA Winter Conditions. Framing, cladding, frame type and other items will affect the overall thermal values of a complete window.
U Value: the total heat transfer out of a window (Btu/hr-sq ft-F or W/sq m- C). The lower the number the better the glass.
R-Value: the amount of heat retained by the window. The higher the number the better the glass.
Solar Heat Gain Coefficient: the amount of solar radiation which enters the house through radiation. This is expressed as a dimensionless number between 0 and 1. It represents the heat gain through 3mm clear glass.
Visible Light Transmittance: measures how much of the visible light is entering the building through the glass. 1.0 would mean all of the light was getting through and 0 would mean none of it was getting through. Our atmosphere naturally filters out 5% of the visible light. Clear glass with no coatings lets in approx. 90% of visible light.