Energy-Efficient Windows for a Cooling Climate
Most window-efficiency advice on the internet was written for people trying to keep heat in. Wichita Falls has the opposite problem for most of the year: the job of your glass is to keep the sun’s heat out while your air conditioner fights a 100-degree afternoon. That flips which numbers matter. The solar heat gain coefficient (SHGC) — the fraction of solar radiation your window admits — is the headline figure here, and for North Texas you want it low, down in the low 0.20s for serious west and south exposures. U-factor, the insulation number, still matters for January — but SHGC is what your August electric bill notices.
The Stack That Does the Work
- Low-E coating, solar-control tuned. Not all Low-E is the same recipe; hot-climate coatings reject infrared aggressively while keeping the glass visually clear. This is the difference between a west room you avoid at 5 p.m. and one you can sit in.
- Double-pane insulated glass with argon fill. The sealed gap is the insulator; argon slows conduction further at modest cost. Triple-pane exists but rarely pays for itself this far south — an honest installer will tell you that.
- Warm-edge spacers between the panes, so the glass perimeter is not a thermal shortcut that sweats in winter.
- Insulated frames — multi-chamber vinyl or thermally broken aluminum. The best glass package mounted in an unbroken aluminum frame leaks heat around its own edges; the frame is part of the system.
- The install itself. An uninsulated perimeter gap can waste a chunk of what the glass package earns. Efficiency is a chain, and the site work is a link.
Reading the NFRC Sticker Without a Decoder Ring
Every certified window carries an NFRC label with the same few numbers. For this climate, read them in this order: SHGC (lower is better here), U-factor (lower is better everywhere), then air leakage. ENERGY STAR qualification for our region is a reasonable floor — but two qualified windows can still differ, and on a wall of west glass the SHGC difference is real money. Bring us the exposures that cook and the rooms that never cool, and the estimate will match the glass package to the wall instead of quoting one spec for the whole house.
One more honest note: the federal tax credit that used to sweeten efficient-window purchases ended for installations after December 31, 2025. Anyone still promising it is reading last year’s brochure — details here. The savings case for efficient glass in this climate stands on the electric bill alone.