Understanding NFRC Labels: What to Look for in Replacement Windows

When it comes to replacement windows, energy efficiency matters—not just for homeowners, but for the contractors who install them. That’s where the NFRC label comes in. Whether you're a contractor helping clients choose the right windows or a homeowner looking for clarity, understanding what’s on that label can make a big difference in comfort, performance, and savings.

At CGR Wholesale, we make it easy to choose top-quality, energy-efficient windows by carrying trusted brands that are NFRC-certified. Here’s how to read the label and what each rating really means.

What is the NFRC?

The National Fenestration Rating Council (NFRC) is a non-profit organization that provides independent, third-party testing of windows, doors, and skylights. Their standardized rating system allows consumers and contractors to compare energy performance across different products, regardless of brand.

Every NFRC-certified window comes with a label showing specific performance metrics. These numbers help you understand how the window will perform in terms of insulation, heat control, and light transmission.

How to Read the NFRC Label

Let’s break down the key components you'll find on an NFRC label:

1. U-Factor

• What it means: Measures how well a window prevents heat from escaping.

• The lower the number, the better the insulation.

• Ideal range: Look for a U-Factor of 0.30 or lower for cold climates like Pennsylvania.

2. Solar Heat Gain Coefficient (SHGC)

• What it means: Indicates how much heat from the sun is admitted through the window.

• Lower numbers reduce heat gain, which is ideal for keeping interiors cooler in summer.

• Ideal range: 0.25–0.40 depending on the home’s exposure to sunlight.

3. Visible Transmittance (VT)

• What it means: Shows how much natural light passes through the window.

• Higher VT = brighter interior, but may also mean more solar heat.

• Ideal range: 0.40–0.60, depending on your light and privacy needs.

4. Air Leakage (AL)

• What it means: Measures how much air can enter through gaps in the window frame.

• Lower values = tighter seal and better performance.

• Ideal rating: ≤ 0.30 (though not always listed on every label).

5. Condensation Resistance (CR) (optional)

• What it means: Indicates how well the window resists condensation build-up.

• Higher number = better resistance to fogging.

• Scale: Rated from 1 to 100 (higher is better).

Why This Matters for Contractors

As a contractor, you want windows that:

• Meet local energy codes and building standards

• Qualify for ENERGY STAR® ratings

• Provide lasting performance and client satisfaction

NFRC labels help you select products that deliver on performance and avoid callbacks or complaints. By sourcing your replacement windows through CGR Wholesale, you get access to ENERGY STAR-rated products, trusted brands like ProVia, and expert guidance every step of the way.

Find the Right Window with CGR Wholesale

At CGR Wholesale, we’re committed to making your job easier by providing top-tier window brands that carry NFRC certification. We offer competitive bulk pricing, fast delivery, and expert support to help you select the perfect products and streamline your ordering process. Whether you’re replacing just a couple of windows or outfitting an entire new build, CGR Wholesale is your trusted partner every step of the way.