Thermal Performance Data
Earthwise/ American Window Thermal Performance
| Product | Total Unit U- Factor | Total Unit SHGC | Visible Light Transmittance | UV Block |
|---|---|---|---|---|
| The Horizon, Yellowstone or PrimeLok Single Hung | Clear: 0.49 Low E and Air: 0.34 | Clear: 0.59 Low E and Air: 0.31 | Clear: 82% Low E and Air: 57% | Clear: 42% Low E and Air: 84% |
| The Solaris, Yosemite, or PrimeLok Double Hung | Clear: 0.49 Low E and Air: 0.35 | Clear: 0.58 Low E and Air: 0.30 | Clear: 82% Low E and Air: 54% | Clear: 42% Low E and Air: 84% |
| The Horizon, The Solaris, Yellowstone, Yosemite or PrimeLok Single Slider | Clear: 0.49 Low E and Air: 0.34 | Clear: 0.55 Low E and Air: 0.31 | Clear: 82% Low E and Air: 56% | Clear: 42% Low E and Air: 84% |
| The Horizon, The Solaris, Yellowstone, Yosemite or PrimeLok Picture Window | Clear: 0.49 Low E and Air: 0.33 | Clear: 0.62 Low E and Air: 0.32 | Clear: 82% Low E and Air: 59% | Clear: 42% Low E and Air: 84% |
| The Eclipse, Grand Mesa or TruLok | Clear: 0.49 Low E and Air: 0.35 | Clear: 0.58 Low E and Air: 0.30 | Clear: 82% Low E and Air: 54% | Clear: 42% Low E and Air: 84% |
| The Solstice, Grand Teton or GrandLok | Clear: 0.49 Low E and Air: 0.35 | Clear: 0.58 Low E and Air: 0.30 | Clear: 82% Low E and Air: 54% | Clear: 42% Low E and Air: 84% |
| The Aurora or Cascades Casement / Awning | Clear: 0.45 Low E and Air: 0.31 | Clear: 0.56 Low E and Air: 0.31 | Clear: 82% Low E and Air: 72% | Clear: 42% Low E and Air: 84% |
Terminology
Emissivity is a measure of a surface’s ability to emit long-wave infrared radiation or room temperature radiant heat energy. Emissivity varies from 0 (no emitted infrared) to 1 (100% emitted infrared). The lower the emissivity, the lower the resultant U-Value.
U-Value is the amount of heat transmitted by the window. The lower the number, the more efficient the window is in reducing winter heat loads and costs. Expressed in Btu/hr.ft2.F.
R-Value designates a window’s resistance to heat flow. This number is the inverse of the U-Value: the higher the number, the more efficient the window in reducing winter heating costs. Expressed in hr.ft2.F/Btu.
Solar Heat Gain Coefficent is the fraction of incident solar radiation entering a home through the windows. The lower the number, the better the window is at preventing solar gain – critical to reducing summer cooling costs.
