The most important envelope parameter is solar heat gain coefficient
, but ratio between VT and SHGC must be taken into account.
Determining window solar heat gain coefficient
. ASHRAE Journal 36(8):26-32.
Practical equations for the overall coefficient of heat transfer, [U.sub.v,m], solar heat gain coefficient
, [SHGC.sub.V,m], and cavity air temperature, [t.sub.V,m], for window systems were theoretically derived.
The authors found good correlation with the solar transmission model for blinds, but noted that the outdoor side convection coefficient is likely a mild, but still important factor that affects the solar heat gain coefficient
(SHGC) of window assemblies, and could not be captured in their indoor experiments.
Glazing that combines high solar heat gain coefficient
(SHGC [greater than or equal to] 0.5) and insulation should be adopted to exploit passive solar gains in the heating season.
--a solar heat gain coefficient
of the windows (SHGC);
Alongside the U-Factor, The Solar Heat Gain Coefficient
(SHGC) is another widely referred to rating that measures how much heat is transmitted through a window by the sun's rays.
This required the glass to have a value of 0.4 and a solar heat gain coefficient
of as low as 0.25.
The low-e, Energy Star certified windows serve to minimize heat loss, and their low solar heat gain coefficient
works with the position of the solar air panels to limit heating of the home's interior during the summer months.
Our windows (ModernView) were modestly priced and had the best value for our purposes: U factor .38, Solar Heat Gain Coefficient
.58, and Visual Light Transmittance of .60.
The second major factor is solar heat gain, also referred to as the solar heat gain coefficient
* Solar heat gain coefficient
, The fraction of solar radiation admitted through or absorbed by a window.