When it comes to choosing energy-efficient windows or doors, two certifications stand out: ENERGY STAR® and NFRC. Both play an essential role in evaluating and ensuring the energy performance of products, but they do not serve the same function. Understanding their differences helps you choose more wisely the products best suited to your home and climate. This article explains in detail the role of each certification, their criteria, and how they contribute to better comfort and lasting energy savings.
Summary of Key Points
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ENERGY STAR® and NFRC aim to ensure the energy performance of windows, doors, and skylights.
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ENERGY STAR® sets the minimum thresholds for energy efficiency.
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NFRC measures and publishes actual performance values.
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Both rely on independent testing and verified data.
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The main indicators are U-factor, SHGC, visible transmittance, and condensation resistance.
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ENERGY STAR® products may be eligible for certain grants or rebates.
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The choice depends on local climate, building type, and energy priorities.
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Professional installation is essential to guarantee the expected performance.
Understanding the Certifications: ENERGY STAR® and NFRC
Energy certifications offer consumers a reliable benchmark for assessing product quality and performance. They ensure that windows and doors meet precise standards for insulation, durability, and energy savings.
Although complementary, their roles differ: ENERGY STAR® sets the minimum energy-performance requirements for a product to be recognized as energy-efficient, while the NFRC (National Fenestration Rating Council) measures and publishes performance results according to standardized protocols. Together, they ensure transparency and reliability when choosing residential products.
What Is ENERGY STAR® Certification?
ENERGY STAR® is a recognized international programme, managed by the Environmental Protection Agency (EPA) in the United States and supported by Natural Resources Canada. It identifies products that use less energy while maintaining an excellent level of comfort and quality.
ENERGY STAR®-certified products—whether windows, doors, or skylights—are designed to deliver optimal performance in various climates. They typically incorporate low-emissivity (Low-E) glazing, warm-edge spacers to limit condensation, insulating gases such as argon or krypton, as well as highly insulating frames made from durable materials like PVC or aluminum-PVC hybrids. These features aim to reduce heat loss in winter, limit solar gain in summer, and provide consistent indoor comfort year-round.
Criteria and Testing to Obtain ENERGY STAR® Certification
Before being certified, each product undergoes independent testing in an accredited laboratory. The results are then verified by the NFRC. This two-step process ensures the product meets the strict requirements of the ENERGY STAR® programme.
The main evaluation criteria are shown below:
| Criterion | Description | Goal |
|---|---|---|
| U-factor | Measures the thermal insulating ability of a window or door | Lower = better insulation |
| SHGC (Solar Heat Gain Coefficient) | Quantifies solar heat transmitted indoors | Adjusted by climate |
| AL (Air Leakage) | Indicates the amount of air that infiltrates through the product | Lower = better airtightness |
| VT (Visible Transmittance) | Percentage of natural light transmitted | Higher = brighter room |
| Condensation resistance | Glazing’s ability to prevent fogging | Higher = better comfort |
These criteria help ensure uniform energy performance tailored to Canadian climate zones.
Benefits of ENERGY STAR®-Certified Products
ENERGY STAR® windows and doors can reduce energy losses by up to 13% compared with single-glazed or non-insulated products. They help lower heating and cooling consumption while providing improved acoustic comfort.
They may also provide access to financial incentives, depending on current provincial and federal programmes. Beyond the savings, these products contribute to a home’s durability and a reduced carbon footprint.
The NFRC’s Role in Product Evaluation
The National Fenestration Rating Council (NFRC) is an independent organization that certifies the energy performance of windows, doors, and skylights. Unlike ENERGY STAR®, it does not set thresholds to meet; instead, it provides precise, verified data that allow products to be compared with one another.
ENERGY STAR® therefore acts as a compliance label, while the NFRC serves as a technical evaluation tool. A window or door with ENERGY STAR® certification must first be tested and evaluated by the NFRC, which ensures the reliability of the data shown on the product label.
How the NFRC Tests and Labels Products
The NFRC evaluates finished products in laboratory conditions that replicate various climates. Each product receives a standardized label displaying measured values: U-factor, SHGC, visible transmittance, air leakage, and condensation resistance.
This information helps consumers easily compare available models. For example, a south-facing home will benefit from a product with a lower SHGC, while a north-exposed building will gain from glazing with a higher SHGC. This transparency supports choices tailored to each situation.
Key Indicators Used by the NFRC
NFRC measurements are universal and comparable across products. A low U-factor indicates better insulation, while a higher SHGC can be advantageous in colder regions where solar heat contributes to passive heating. Visible transmittance (VT) gauges natural brightness, while air leakage (AL) and condensation resistance ensure comfort and product durability. Together, these indicators provide a complete picture of energy performance.
Comparison: ENERGY STAR® vs. NFRC
Common Ground
Both programmes share a goal: to improve the energy performance of residential buildings and reduce energy consumption. They rely on independent testing and internationally recognized protocols. Their complementarity guarantees consumers a product that is reliable, durable, and compliant with the highest standards.
Key Differences
ENERGY STAR® sets energy-excellence criteria and highlights products that meet them.
NFRC, for its part, provides the measured data but does not determine whether a product is “efficient” or not.
In short: ENERGY STAR® is a performance label, while NFRC is a comparison tool. To choose effectively, it’s best to use both—ENERGY STAR® certification for assurance of efficiency, and NFRC values to fine-tune selection based on your climate and preferences.
Tailoring Your Choice to Climate and Home
In Hot Climates
A low SHGC helps block solar heat and maintain a comfortable indoor temperature. Low-E glazing and insulating frames are ideal for reducing cooling loads and improving energy efficiency in sun-exposed homes.
In Cold Climates
A low U-factor and a moderately high SHGC help retain indoor heat while taking advantage of free solar gain. This combination improves comfort and reduces heating needs during the winter months.
Energy-Efficient Windows and Doors: A Tangible Environmental Impact
ENERGY STAR®-certified products directly help reduce greenhouse gas emissions by lowering heating and cooling needs. Installing high-performance windows, doors, or skylights is a simple, lasting way to improve a home’s energy efficiency while shrinking its carbon footprint.
Several financial incentive programmes encourage this type of renovation. It is therefore recommended to check available incentives before starting your project to optimize your investment.
The Importance of Professional Installation
A window or door can only deliver its full potential if installed correctly. Professional installation ensures perfect airtightness, prevents air and water infiltration, and guarantees that ENERGY STAR® or NFRC performance is fully achieved.
Hiring a qualified installer is therefore essential: it extends the product’s lifespan, preserves its energy efficiency, and ensures compliance with quality standards.
Conclusion: ENERGY STAR® or NFRC?
The choice between ENERGY STAR® and NFRC depends primarily on your priorities. If you want an official guarantee of energy efficiency, ENERGY STAR® is the reference. If you want to compare multiple products based on measured values, the NFRC label is the ideal tool.
These two certifications complement each other: they enable you to choose high-performance products, improve your home’s thermal and acoustic comfort, and sustainably reduce energy consumption. By selecting certified windows and doors installed by qualified professionals, you ensure lasting performance and increased comfort for your home.
