Low-E Coating – Resource

Do you have a question about Low-E Coating?

What is Low-E glass?

Low-E (low-emissivity) glass has a special coating that reduces heat transfer and improves energy efficiency.

What does Low-E stand for?

Low-E stands for “Low Emissivity,” meaning it reduces the amount of infrared and ultraviolet light passing through.

How does Low-E coating work?

It reflects infrared heat while allowing visible light to pass through, helping to keep interiors warmer in winter and cooler in summer.

Is Low-E glass clear or tinted?

Low-E glass is usually clear but can have a slight tint depending on the coating type.

What are the two main types of Low-E coatings?

Hard coat (pyrolytic) and soft coat (sputtered).

What is hard-coat Low-E glass?
It’s created during manufacturing, with the coating fused to the surface for high durability and scratch resistance.
What is soft-coat Low-E glass?
It’s applied in a vacuum chamber after the glass is formed. It provides superior performance but requires sealing within insulated glass units (IGUs) for protection.
Which Low-E coating is more energy-efficient?
Soft-coat Low-E, as it has lower emissivity and better insulation.
Which Low-E glass is better for cold climates?
Hard-coat Low-E, since it allows beneficial solar heat gain while still providing insulation.
Which Low-E glass is better for hot climates?
Soft-coat Low-E, as it blocks more solar heat and reduces cooling costs.

Does Low-E glass reduce energy bills?
Yes. It lowers heating and cooling requirements by improving insulation.
How does Low-E glass affect U-value?
It lowers the U-value, meaning less heat loss and improved thermal efficiency.
What is the Solar Heat Gain Coefficient (SHGC)?
It measures how much solar radiation enters through the glass — a lower SHGC means less heat gain.
Does Low-E glass block UV rays?
Yes. It blocks up to 99% of UV radiation, protecting interiors from fading.
Can Low-E glass reduce condensation?
Yes. By keeping interior surfaces warmer, it helps prevent moisture buildup.

Can Low-E glass be used in single-pane windows?
It’s most effective in double- or triple-pane systems, though limited single-pane uses exist.
Does Low-E glass need special frames?
No, but pairing it with insulated or energy-efficient frames (like uPVC or fiberglass) improves results.
How do you clean Low-E glass?
Use mild soap and water with a soft cloth. Avoid harsh or abrasive cleaners that could damage coatings.
Is Low-E glass more fragile than regular glass?
No. However, soft-coat Low-E must be sealed inside IGUs to protect its surface.
Can you install Low-E glass in skylights?
Yes. It reduces solar heat gain and glare, keeping rooms cooler and more comfortable.

Is Low-E glass better than tinted glass?
Yes. It controls heat and UV without significantly reducing natural light.
How does Low-E compare to double glazing?
Double glazing with Low-E is more energy-efficient than standard double glazing.
Does Low-E work better than window film?
Yes. It’s built into the glass and won’t peel, bubble, or degrade over time.
Can Low-E replace tempered glass?
No, but it can be combined with tempered glass for both safety and energy performance.
Does Low-E glass work with argon gas-filled windows?
Yes. Argon gas enhances insulation when used with Low-E coatings.

Does Low-E glass look different from regular glass?
It may show a subtle tint or slight reflectivity, but generally appears clear.
Does Low-E glass cause glare?
No. It actually reduces glare compared to plain glass.
Can Low-E glass be used for decorative windows?
Yes. It’s available in various styles and can include decorative patterns or tints.
Does Low-E glass affect window tinting?
Yes. Adding aftermarket tint can alter performance; it should be tested for compatibility.
Can you see through Low-E glass at night?
Yes, though it may appear slightly more reflective in dark conditions.

Is Low-E glass beneficial in all climates?
Yes, with different coatings optimised for warm or cold regions.
Can Low-E glass reduce heat loss in winter?
Yes. It reflects indoor heat back inside, improving warmth and comfort.
Does Low-E glass overheat in summer?
No. It reduces heat gain and helps maintain cooler interiors.
Can Low-E be used in coastal areas?
Yes, when paired with corrosion-resistant frames.
Is Low-E suitable for high-altitude locations?
Yes, though gas-filled units may need pressure-balanced designs.

Is Low-E glass expensive?
Yes, it costs more than standard glass but offers long-term savings.
Does Low-E glass increase home value?
Yes. Energy-efficient windows are attractive to buyers and improve comfort.
Are there tax credits for Low-E glass?
In many areas, yes — as part of energy-efficiency or sustainability incentives.
How long does Low-E glass last?
Decades when properly installed and maintained.
Is Low-E glass worth the investment?
Yes, for reduced energy bills, improved comfort, and environmental benefits.

Can Low-E glass be laminated?
Yes. Laminating adds strength, security, and acoustic insulation.
Does Low-E glass reduce outside noise?
Yes, especially when combined with laminated or triple-pane configurations.
Does Low-E glass affect cell signals?
Slightly — its metallic coating can weaken radio or mobile signals.
Can Low-E glass be cut after manufacturing?
Hard-coat glass can; soft-coat must be handled before it’s sealed in units.
Does Low-E glass work with smart windows?
Yes. It integrates well with electrochromic and switchable technologies.
Can Low-E glass be recycled?
Yes, though its coating requires specialised recycling processes.
What’s the difference between Low-E 1, 2, and 3 glass?
Each version improves insulation; Low-E 3 offers the highest performance.
Can Low-E glass be used in historic buildings?
Yes, with custom profiles that maintain original aesthetics.
Does Low-E glass work in triple-pane windows?
Yes. It achieves maximum efficiency when used in triple glazing.
How do you identify Low-E glass?
Use a Low-E detector or view the glass at an angle — you’ll notice a faint coloured reflection.