It is August in the Tri-Cities, the thermometer is flirting with 105°F, and your air conditioner is running from breakfast to bedtime. A surprising amount of that heat is coming straight through your windows. If your home still has clear double-pane (or worse, single-pane) glass, the sun is pouring free heat into your living room all afternoon.

What “Low-E” Actually Means

Low-E stands for low emissivity. It is a microscopically thin, invisible metallic coating applied to the glass that acts like a selective filter: visible light comes through, but a large share of infrared heat is reflected back where it came from. In summer, that means solar heat stays outside. In winter, the same coating reflects your furnace’s heat back inside.

The Number That Matters: SHGC

On every window label you will find the Solar Heat Gain Coefficient (SHGC) — the fraction of solar heat that makes it through the glass. Clear single-pane glass scores around 0.80. A quality low-E window for our climate lands around 0.20–0.30, rejecting roughly two-thirds more solar heat. On a west-facing wall in Kennewick in August, you feel that difference by mid-afternoon.

Real-World Payoff

• Cooler rooms — especially west- and south-facing rooms that used to be unusable after 3 p.m.
• Lower cooling bills — the AC cycles less because less heat enters in the first place.
• Less fading — low-E coatings also block most UV, protecting floors and furniture.

Match the Glass to Our Climate

Eastern Washington is a dual-season challenge: hot summers, cold winters. The right low-E package balances summer heat rejection with winter heat retention. As a Milgard Certified Dealer, we will spec the correct glass package for each side of your house — not a one-size-fits-all order.

Ready for honest answers about your windows, doors, or glass? Schedule a free in-home estimate with our award-winning team. Call us in the Tri-Cities at (509) 586-1177, in Walla Walla at (509) 529-5110, or request your free estimate online.