Thermal Windows vs. ENERGY STAR® Windows — What’s the Difference?

Are you shopping for replacement windows?If so, you’ve probably heard the terms thermal windows and ENERGY STAR® windows. Some people think they’re the same. They’re not,  and knowing the difference can save you money and improve your home’s comfort.

At SRI Energy, we help Tulsa-area homeowners choose certified energy-efficient windows that really perform, not just ones with a good sales pitch.

How to Identify ENERGY STAR® Windows

ENERGY STAR® windows always display an NFRC label. This label shows the window’s official ENERGY STAR rating.

Pro Tip: Always ask for the NFRC (National Fenestration Rating Council) certification. This confirms the window was independently tested, not just approved by the manufacturer.

Here’s what the NFRC looks like:

Why NFRC Ratings Matter

When you invest in replacement windows, you deserve:

• Verified energy efficiency
• Independent performance testing
• The best insulation for Oklahoma’s climate

Without the NFRC label, “thermal windows” might only meet internal company standards, which can vary widely.

Understanding Window Ratings (Simplified)

Choosing windows can feel confusing. Let’s break down the key ratings:

🔹 U-Factor

What it means: How well a window stops heat from escaping.
Best option: Lower numbers mean better insulation.

🔹 Solar Heat Gain Coefficient (SHGC)

What it means: How much solar heat enters through the glass.
Best option: In Tulsa’s warm climate, choose lower SHGC values to block heat.

🔹 Air Leakage

What it means: How much air sneaks around the window frame.
Best option: Lower air leakage ratings for tighter, more efficient windows.

🔹 R-Value (Related to U-Factor)

What it means: Measures insulation.
Best option: Higher R-Value = better performance.

Tip: The U-Factor is the easiest way to compare window insulation. Lower is better.

Why ENERGY STAR® Windows Are Worth It

ENERGY STAR windows aren’t just about numbers. They can:

• Lower your heating and cooling bills
• Keep your home more comfortable
• Reduce outside noise
• Boost your home’s resale value
• Qualify for rebates or tax incentives

Learn more about our ENERGY STAR® windows or schedule a consultation today.

Why Choose SRI Energy?

Homeowners across Tulsa, Broken Arrow, Claremore, and NE Oklahoma trust us because:

✔ We offer ENERGY STAR® window options
✔ Our team includes BPI Certified Building Scientists
✔ We give honest, expert advice
✔ Our pricing is competitive
✔ Financing is available

Schedule Your Free Consultation

Ready to upgrade your home’s windows?
Contact SRI Energy today for a free consultation and discover the difference certified energy-efficient windows can make.

Frequently Asked Questions

Q: Are thermal windows ENERGY STAR® certified?
A: Not necessarily. Only windows with the NFRC ENERGY STAR label meet strict federal standards.

Q: What window ratings should I look for?
A: Check the U-factor (lower is better), SHGC (lower for hot climates), and air leakage.

Q: Are ENERGY STAR® windows worth the cost?
A: Yes! They can lower bills, improve comfort, and may qualify for incentives.

Q: How can SRI Energy help?
A: We offer ENERGY STAR® certified windows, expert installation, and honest advice tailored to Tulsa’s climate.

Alex Green Home Energy Efficiency Expert

Alex Green is a passionate and knowledgeable content creator specializing in home energy efficiency. With a background in environmental science and digital marketing, Alex has a deep understanding of how insulation, windows, and smart home upgrades contribute to energy savings. They are skilled at translating technical concepts into engaging, easy-to-understand blog content for homeowners looking to improve comfort, reduce energy costs, and make eco-friendly choices.

See Full Bio