Different Types Of Low-E Glass and Their Right Uses

Types Of Low-E Glass

Now you can lower the energy use and heavy bills just with the right weapon.

Do you know what’s that? It’s the Low-E Glass.

Having a Low-E glass can give you a high range of benefits.

From the tropical region? The glass will surely block solar heat.

From the frigid zone? Let it trap furnace heat then.

Not only it’ll help you use the cold and warmth of the environment but also make you forget about electrical machines.

But before, you need clear information on the types of Low-E glass and how they work. Then you’d be able to use it right. In this article, we’ll help you with all the information you need.

What Is Low-E Glass?

Low-E is short for low emissivity. Glass that comes coated with invisible layers of metallic oxide is what you call Low-E Glass.

The coatings are extremely thin layers on the glass surface. They limit or prevent wavelength of sunlight from entering the pane, deflect infrared light and ultraviolet rays back into the environment and still allow passing of visible light.

Both the infrared light and UV rays are actually two big dangers. You’d find them responsible for burning skin, fading upholstery and damaging interior materials like wall coverings, fabrics and exterior walls.

Low-E coatings protect from such harmful effects. Plus, they help heighten the insulating performance of glass so you have added energy efficiency.

The Low-E coatings on a glass work in 2 different ways-

  1. Prevent heat escaping and keep them inside your house during winter.
  2. Prevent heat from entering your home during summer and keep the interior cool.

Two Types Of Low-E Glass

Passive Low-E Glass

Passive Low-E Glass

Low-E glasses with passive heating effect are used in lots of today’s modern green buildings. After the 1970s foreign oil crisis in the western world, countries including United States, Western Europe, Canada, New Zealand and Australia faced extensive petroleum shortages and higher prices.

After that, a coating technology was engineered in the 1980s. The technology mainly helped keep warm inner air from escaping through the glass, aiding the houses to use less energy for heating.

How does the technology work?

Passive Low-E coatings let a bit of the suns short-wave infrared energy pass through the glass. It’s absorbed by the people, walls, floors and furniture, helps heat your house during winter and re-radiates the long-wave heat energy internally.

In short, the passive-heating effect maximizes solar heat to pass into your space and traps heat. Thus, it reduces dependency on artificial heating systems. The coatings are very ideal for cold climates since they lower the expense of heating your house. 

1.1 How Is It Made?

You can make passive Low-E coatings with a thermal decomposition process. It involves pyrolytic glazing with a thin ribbon of molten tin oxide that you apply to the glass sheet online while the glass is still hot on the float line.

This causes the coating to fuse with hot glass surface and creates a strong bond. Since the material is extremely hard to scratch or remove, it’s also known as hard-coat. However, their emissivity isn’t as low as the soft coatings.

1.2 Uses Of Passive Low-E Glass

  • Storm doors
  • Single-glazed windows.
  • Partitions

2. Solar Control Low-E Glass

Solar Control Low-E Glass

Developed in the early 1990s, solar control Low-E coatings cut up to 60% of solar heat passing into the house. They mainly offer thermal insulation so it can keep the interior cool in summer and warm in winter.

Usually, the coatings have lower emissivity while coming with greater solar control performance. Hence, you get to enjoy the benefits of the highest-performing solar control.

The coatings are ideal particularly for hotter places or the buildings that get lots of direct sunlight.

Unlike passive heating effect, its purpose is not to trap heat but block it. And as the house would stay cool for this, it reduces the energy cost that comes with air-conditioning.

For the past several years, manufacturers have been working on the advancement of the solar control glass. They incorporated as many as 3 layers of metals to the stack of coating to intensify the ability of solar control Low-E glasses further.

2.1 How Is It Made?

You would use Magnetron Sputtering Vapor Deposition method to manufacture Solar Control Low-E coatings.

It involves the application of the coatings with a layer of zinc, silver or tin off-line to the pre-cut glass. The process happens in a vacuum chamber filled with an electrically-charged inert gas at room temperature.

As they are fairly delicate, you must seal them in a laminated unit or insulated glass to keep the bond strong. Such coatings are also known as soft coats because of their characteristics.

There’s also an alternative method. For this, the coatings have to be applied to the substrate after the glass cools down. Albeit the alternative process generates a more fragile coating than a hard coat, it gives you more effective metal deposition on the glass substrate.

2.2 Uses Of Solar Control Low-E Glass

  • Doors
  • Roofing
  • Canopies
  • Façade  

Advantages Of Low-E Glass

Heat Gain For Winter And Heat Loss For Summer

A hard coat Low-E glass would be great if you live in a colder climate. As mentioned earlier, it enables the short-wave infrared ray to pass through the glass and help heat up the space in winter.

If you live in hotter climate, then a soft coat Low-E glass would be perfect. It helps give you better UV protection by rejecting radiation and controlling solar glare.  

Protection From UV Rays

UV rays are those evil eyes that may cause damages to your skin and health. The radiation also has an annoying habit of affecting your fittings and carpets with bleaching effect. As a result, the fixtures end up losing color.

But Low-E glass will restrict the radiations from entering your space by resisting certain wavelengths that can be harmful. Not only it helps protect you and your family, but your furnishings too.

Energy Efficiency

You’d be able to save lots of money through the use of Low-E glass, making your house extremely energy efficient. Since it keeps the space cool in summer and warm in winter, you don’t have to use air-conditioner or heater. That means no more heavy bills on your tab!


The glass with low emissivity coating boasts other versatile features. It helps add more seclusion so you can enjoy a private life. Neither it leaks noise outside nor it brings noise inside thanks to the noise-proofing technology.


Because of the smart manufacturing process, it’s difficult to scratch off, wipe away or damage the coatings. The reason is that the coating comes inside of the glass making it a durable material to have. Also, these glasses are very easy to clean and maintain.

Bright View

Low-E glass helps block UV rays and infrared light. However, it doesn’t mean the glass will block all the lights. Certainly, it’ll reduce the level of visible light a little if you compare it with the transparent pane. That said, the glass will allow for enough daylight to brighten up your space and make it look bigger.

Disadvantages Of Low-E Glass


Low-E glass comes pricier than other types. Of course, it’s worth the price given the benefits it comes with.

Out of the two types, a soft coat glass would cost more than the hard coat due to the control of glare it provides.

Haze In The Pane

You may notice the glass exhibiting a natural grey haze. It’s more visible when the glass is viewed against a dark setting or in direct sunlight. This may make it slightly hard to see through.

However, in most cases, the haze isn’t obvious.

Appearance Of Different Color

The glass with Low-E coatings reflects more color. So, it may appear slightly different in color compared to transparent glass. You would notice it more if you place the glass next to transparent glass.

So, we suggest that you don’t assemble glasses with both the variations.

Finals Words

Low-E glass is one of the useful glass types that contains several advantages. Apart from reducing harmful rays, it offers durability and the right amount of warmth or brisk feel.

The function of Low-E glass is simple. It converts the radiation of sunlight, neutralizes the evil rays and lets the good rays pass through.

Regardless of the types, the function is the same. You’ll just need to know which one would suit best depending on your climate.

And now that you know about the types of Low-E glass with their purpose, hopefully, you’ll get to make the most of it.

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