Alpen High Performance | Windows & Doors

Window Certifications: What do they mean and why are they important?

August 15, 2019

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People are skeptical, and in today’s world it can be especially difficult to believe much of what we’re told is 100% true. That’s probably a healthy thing!

So, how do we know that what we’re being told is the truth—that the window you’re purchasing insulates like it should?

Which Window Certifications…and Why?

Certifications provide third-party verification of performance, quality, and suitability claims.
Some certifications are well known: You should only use light fixtures that are UL certified and you should only fly in planes that have been certified by the FAA.

In the construction industry, you should only use windows that have verified performance certifications.
But which certifications should you be looking for?

NFRC
The National Fenestration Rating Council assigns energy performance ratings in multiple categories, including U-factor, solar heat gain coefficient, visible transmittance, condensation, and air leakage.

There are several methods of measuring window U-factors but the standard in North America is the one required for NFRC certification. Alternate methods can be confusing or even misleading and give wildly varying numbers.
NFRC ratings guarantee your window’s R-value/U-factor, allowing you to make accurate calculations for any building in the US.

Passive House
Both PHIUS and PHI provide lists of preferred products. PHIUS “approves” products and PHI “certifies” them (both through third-party testing agencies).

These certifications/approvals provide comprehensive information, climate specific recommendations, and the calculation values needed to easily specify high-performance products in passive house projects.

AAMA
The American Architectural Manufacturer’s Association assigns performance grades based on: Air leakage, water penetration, wind and forced entry resistance, and structural pressure.

The AAMA Certification Program is the only program in the window and door industry that requires that components used in the finished window and door assembly pass their own set of performance tests. The program also requires the use of AAMA-accredited labs so that tests are performed by qualified, experienced professionals using properly calibrated equipment. Two surprise manufacturing plant inspections every year offer additional quality assurance—translating to added peace-of-mind.

Declare Label
Declare is “an ingredients label” for the building industry that is administered and developed by the International Living Future Institute. It provides information on where a product comes from, what it’s made of, and if it’s recyclable—factors affecting both health and sustainability. As an effort to track overall toxicity and environmental impact, it’s often used as an indicator of “healthy” building components.

OITC/STC
Outdoor/Indoor Transmission Class (OITC) and Sound Transmission Class (STC) are measurements of how much “soundproofing” a window provides. They are verified by testing to ASTM E90 standards for sound transmission loss.

OITC is the ideal measurement standard for blocking low frequency “street noise” (car horns, sirens, construction, etc). STC is better suited for blocking out high frequency “interior noises” (televisions, conversations, office equipment, etc)

Energy Star
Administered by the US Environmental Protection Agency, Energy Star certification requires an NFRC certification and provides zone-specific recommendations for the window (similar to, but less detailed than PHIUS certifications, with 4 zones vs. 10 zones) based on a combination of U-factor and SHGC (found here). Additionally, it provides a rough estimate of annual energy cost savings when replacing single- or double-pane windows.

Alpen windows are independently NFRC, PHI, AAMA, Declare and OITC/STC certified as well as PHIUS verified because we believe you should really know what you’re buying and you deserve the truth.

Everyone should insist on that openness and transparency.