These FAQs answer questions you might have about Andersen® HeatLock® glass.
Frequently Asked Questions about HeatLock® Glass Coating
Want to learn about HeatLock glass? Planning to buy an Andersen product with HeatLock glass, or perhaps you already have it? This article has the answers you need.
Expand the sections below to view the FAQs.
Learn About Andersen® HeatLock® Glass
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Answer
What is HeatLock® glass coating?
HeatLock® is an additional Low-E (low-emissivity) glass coating offered by Andersen® that reduces heat transfer, helping keep heat in your home rather than letting it escape.
How does HeatLock® work?
HeatLock® glass coating can be applied to the interior surface of most Andersen windows and patio doors. It reflects radiant heat that normally escapes through your window glass back into the room.
What are the benefits of HeatLock® coating?
HeatLock® glass coating is ideal for Northern climates that experience frequent cold weather.
When used with a traditional Low-E coating, HeatLock® interior coatings enhance the glass unit's insulation by creating two (2) Low-E layers that reflect heat into your home, resulting in lower U-Factor values (the lower the U-factor, the better the window insulates).
Used with SmartSun™ glass, HeatLock® coating offers the benefits of Low-E glass and helps shield your home from the sun’s heat, filtering out 95% of harmful UV rays while letting sunlight through.
Do windows and patio doors with HeatLock® coating look different?
Yes, windows and patio doors with HeatLock® glass coating look slightly different from those without it.
Note: Andersen does not recommend mixing units with and without HeatLock® coating.
Are windows and patio doors with interior glass coatings (like HeatLock®) more prone to condensation on the inside?
Since the interior glass surface may be cooler than glass without the HeatLock® coating, condensation may occur in the interior room.
Note: Interior condensation depends on several factors, such as:
Can I still get applied grilles on a unit with HeatLock® glass coating?
Yes. The availability of different grille options remains unaffected by HeatLock® coating.
Is HeatLock® glass coating available with obscure, textured, or patterned glass?
No the HeatLock® glass coating cannot be applied to glass that is obscured, textured, or patterned.
Can I add HeatLock® glass coating to my existing Andersen® windows or patio doors?
No, unfortunately, there is currently no way to apply the HeatLock® glass coating to windows or patio doors that are already installed.
How does HeatLock® glass coating affect a unit's performance (e.g., NFRC values, STC/OITC)?
The primary effect of using HeatLock® technology is improved thermal performance, specifically U-Factor values. There may be some slight variations in Solar Heat Gain Coefficient (SHGC) or Visible Light Transmittance (VLT), but they are typically minimal. Other values, such as Sound Transmission Class (STC), Design Pressure (DP), or Performance Grade (PG), are unaffected by the HeatLock® coating.
Already Own an Andersen® Product with HeatLock® Glass?
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Answer
How do I tell whether my existing Andersen® windows or patio doors have a HeatLock® glass coating?
Check the AW glass logo, which can be found in one of the four corners of the visible glass on your window or patio door. It will include a callout if it has a HeatLock glass coating.
Example of Andersen corner-window logo indicating HeatLock Glass
Note: If you need help identifying the type of HeatLock-coated productyou have, or want to identify a different Andersen® product, use our Identify Your Product tool.
Do I need to clean HeatLock® glass differently from regular glass?
While there are no specific cleaning recommendations for HeatLock®-coated products, Andersen® recommends avoiding abrasive cleaners, scrub pads, and similar products on HeatLock®-coated glass. These materials could potentially scratch or damage the HeatLock® coating.
Can the HeatLock® glass coating be damaged since it’s on the glass inside my home?
HeatLock® glass coating is not more prone to scratching than non-coated glass. However, the HeatLock® glass coating can be damaged by abrasive cleansers and polishing compounds.
Can I repair scratches or damage to my HeatLock® coated glass?
No, unfortunately, if the HeatLock® coating is scratched or damaged, it cannot be repaired. Any attempt to repair a scratch in the HeatLock® glass coating can cause visible damage to the coating.
