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 |
| SYSTEM V | HS1V-C180/i89 | Dual pane, two Low-E coatings, Argon | 0.209 | 4.783 | 0.623 | 77 |
| SYSTEM V | HS4V-C270/i89 | Dual pane, one Low-E & one SunStop coating, Argon | 0.200 | 4.998 | 0.361 | 69 |
Notes
Values are in IMPERIAL. 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: A measure of the rate of nonsolar heat flow through a material or assembly. The lower the U-Value, the greater a window’s resistance to heat flow and the better its insulating value.
R-Value: A measurement of the resistance of heat transfer through the glass. The higher the R-Value, the better the window insulates against heat.
Solar Heat Gain (SHGC): The amount of the sun’s heat that transfers through glass from the exterior to the interior side. The higher the solar heat gain, the more a window allows heat to pass through into a home.
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.