Disadvantages of low-e glass explained ! Read this now before buying

Over the course of architectural history, windows have occasionally had their moment. Additionally, even if we are not now experiencing the visual apex of the Gothic cathedral era, we are seeing significant advancements in window technology.

Windows can now be a true ally in the construction of high-performing homes, whereas windows were traditionally a definite weak spot in a home’s building envelope.

Disadvantages of low-e glass
Disadvantages of low-e glass

The subject of this article will be low-e glass: what it is, reasons why you might want it, reasons why you might not, and things to think about.

What is low e glass ? What are the disadvantages of low-e glass?

Low emissivity is referred to as low-e. The phrase refers to window glass that has undergone treatment to reduce the amount of heat it transmits. This is how it goes.

An extremely (microscopically) thin layer of indium tin oxide, silver, or zinc oxide has been applied on low-e glass. This layer, which is invisible to us, is reflective and causes infrared and ultraviolet photons to reflect back towards their source.

The amount of visible light that can enter a room is unaffected by the coatings. However, the coating’s ability to reduce the amount of heat transfer between a home and the outside world is made possible by limiting the quantity of infrared light that enters the window.

Things get heated by infrared light. Infrared light passes through regular window glass to create those cosy, sunny areas on our floors where our cats like to lounge. Cats benefit greatly from it, but it has a negative impact on our summer energy costs.

A window can keep the air heated and cooled by our HVAC systems inside our houses by reflecting solar energy back outside with a low-e coating.

Disadvantages of low-e glass

Low-e glass has some disadvantages as well, so let’s look at some typical ones to help you decide if it’s right for you and your house.

Cost of low e glass

The first drawback is the price. Simply put, windows with low-e glass are more expensive. The ROI for low-e windows, according to Energy Manager Steve DeBusk, “tends to be in the 20- to 30-year range” for just glass replacement, not even for window replacement.

However, depending on the windows you’re replacing, the reductions in utility costs may only be marginal. Low-e glass probably won’t make a significant difference if you already have properly functional double-pane windows.

Mobile Signals through low e glass

The impact low-e glass has on cell phone reception is another drawback. Low-e glass is coated with metallic materials that block radio-frequency transmissions in addition to infrared and UV light.

If you have a tech-intensive home life, this might still be something to think about even though the blocking effects will likely be more like a dip in reception than a complete stoppage.


Low-e glass lacks complete transparency. Given that it does reflect some light, the window may appear slightly blue-green. This glass may also cause a slight haze to appear in the window. Although the haze is not a practical issue, it can be for you aesthetically.

So, these are some of the disadvantages of low-e glass.

Technical Considerations before going with low e glass

Passive low-e coatings and solar control low-e coatings are two types of glass coatings that you should be aware of as they could influence your purchasing choice.

More solar energy can pass through windows with passive coatings, which makes them less effective at insulating but more effective at passive heating. These might be a wonderful alternative if your windows are large and south-facing and you live in a chilly climate because you can use some solar energy to heat your home when you need it most.

Because they permit less radiant radiation to pass through, solar control coatings act as a superior insulator. You’ll lose less conditioned air if you choose this option, which may be a good idea if you have a problem with hot summers or if your windows aren’t situated or proportioned properly for passive heating.

The positioning of the low-e coating itself, in addition to its type, has a significant impact on the performance of the window. To alter the operation of a double- or triple-pane window, manufacturers can apply the coating to various glass surfaces.

For instance, a passive low-e coating on the inside surface of the internal pane of a double-pane window would increase the amount of radiant energy that may travel through the window. Better solar energy absorption and insulation would result from the application of a solar control low-e coating to the interior surface of the outermost pane.

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