ENERGY STAR® Windows: How They’re Certified
It’s common practice for homeowners to look for an ENERGY STAR® label while shopping for energy-efficient windows. But how does ENERGY STAR determine which ones are energy-efficient? Kat Construction, a top storm restoration specialist in the state, shows you the certification process for these windows.
The NFRC’s Role
There are two bodies involved in this process: the National Fenestration Rating Council (NFRC) and ENERGY STAR. The NFRC is in charge of testing the performance of a window made by an ENERGY STAR partner in five categories, namely the U-factor, Solar Heat Gain Coefficient (SHGC), the Air Leakage, the Visible Transmittance (VT) and Condensation Resistance.
More often than not, storm damage window repair work necessitates finding replacement parts or a replacement window altogether. While looking for a new one, take note of the five categories found on the NFRC label, as these can give you an idea on how well a window can suit your needs.
U-factor – This value indicates how well a window can insulate. The lower the value, the better.
SHGC (Solar Heat Gain Coefficient) – This value measures how well a window will be able to resist solar heat. The lower the SHGC, the less solar heat that passes through the window.
AL (Air Leakage) – This value gives you an idea on the rate air passes through the window joints. The lower the AL, the less leakage.
(VT) Visible Transmittance – The value measures how much light can pass through the window. The higher the VT, the better the lighting a window can provide.
(CT) Condensation Resistance – The value gives you an idea of how well a window can resist water build-up. The higher the value, the less likely there will be water build-up in the window.
ENERGY STAR’s Role
Using these categories, ENERGY STAR would then determine if the window meets the standards set for a particular climate zone and the energy efficiency guidelines set by the US Environmental Protection Agency (EPA). We recommend you check if the windows supplied by your emergency repair services provider is suitable for your climate zone.
Independent assessments by the NFRC and stringent evaluations by ENERGY STAR ensure certified windows have high energy efficiency.
However, energy-efficient windows won’t be able to lower your energy costs if they’re damaged by an extreme weather event or improperly installed by a contractor. To avoid having to deal with this problem, only hire qualified contractors, like KAT Construction. We’re a window contractor that also offers roof restoration service.
To get a free roof inspection, call (612) 260-1144 or fill out this form. We serve homeowners in Eden Prairie, St Paul, and Duluth, MN.