ENERGY STAR
A government efficiency label. A window earns it by meeting U-factor and SHGC thresholds for its climate zone — a quick “efficient enough” screen, though not the strictest tier.
What it means for you
A useful floor, not a finish line. Most of NC is the South-Central zone (target U ≤ 0.28 and SHGC ≤ 0.23); the mountains are North-Central (U ≤ 0.25, SHGC relaxed to ≤ 0.40). A spec of U ≤ 0.25 and SHGC ≤ 0.23 qualifies anywhere in NC. Still read the actual NFRC numbers — the logo alone doesn't say how far past the line a window is.
Where you'll see it
A logo on the NFRC sticker and in marketing; the qualifying numbers live on the label.
Related terms
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