11/06/2025 Posted By Siarhei Kanushok

The exterior door ensures a modern home’s comfort and savings. Front doors with low-E glass blend elegance with technology, slashing heat loss and trimming energy costs. A unique coating reflects heat, keeping interiors cool in summer and warm in winter, making these models a long-term investment that delivers year-round benefits.

Defining low-E glass: What does “low-emissivity” mean?

Low-E glass is transparent glass with a thin metallic coating that blocks infrared rays.

Standard glass has a high emissivity, meaning it absorbs and radiates a lot of heat (around 91%). Low-E one dramatically reduces this, lowering its emissivity to around 0.1.

How do doors with low-E glass work?

To understand how low-E glass doors work, imagine a thermos that keeps the temperature inside, preventing heat from escaping or entering. Low-emissivity coating works on the same principle: it reflects heat radiation, maintaining a comfortable temperature in the house regardless of the season.

When it is cold outside, this type of glass “returns” the heat emitted by heating devices back inside, and when it is hot, it prevents excess solar heat from entering. At the same time, light and natural brightness remain unchanged, as the coating is invisible to the eye. The result is an optimal microclimate, less strain on heating and air conditioning systems, and significant energy savings.

Blocking UV and infrared rays

Low-E glass acts as an invisible shield, protecting your home from ultraviolet and infrared radiation. UV rays fade paint and damage furniture and flooring over time, while infrared waves penetrate indoors, causing rooms to overheat.

Thus, low-E glass blocks:

  • Up to 99% of UV rays.

  • Up to 70% of sunlight in summer.

The main advantages of installing doors with low-E glass

  1. Enhanced energy efficiency and lower utility bills

The reflective coating retains heat in cold weather and blocks excess sunlight in hot weather, reducing HVAC use.

  1. Improved year-round comfort

These exterior doors maintain a comfortable microclimate in your home, regardless of the weather.

  1. Protection for your home's interior from UV fading

Low-E doors will always protect your furniture, carpets, and walls from fading while maintaining natural transparency and accurate color reproduction.

  1. Reduced condensation

Low-E glass minimizes the cold-glass effect and reduces the risk of condensation, thereby enhancing overall energy efficiency.

  1. Environmental friendliness

It reduces the carbon footprint by lowering energy consumption.

Types of low-E coatings

There are passive and solar control low-E coatings. Both types work on the same principle, but differ in composition, strength, and level of protection.

Passive low-E coatings (hard coat)

Passive or hard coatings are applied to hot glass during the manufacturing process, creating a durable, damage-resistant surface. This type of glass effectively retains internal heat, which is especially essential in very cold climates.

Solar control low-E coatings (soft coat)

The soft or solar control coating is created in a vacuum chamber and consists of several ultra-thin layers of metal. It provides a higher level of solar heat reflection, making it ideal for hot-climate regions.

Performance

Passive low-E (hard coat)

Solar control low-E (soft coat)

Application method

On hot glass during production

In vacuum chamber on finished glass

Strength

High, resistant to damage

More sensitive

Energy efficiency

Maximum heat retention

Maximum protection against solar overheating

Light transmission

Slightly reduced

High, no loss of transparency

Optimal climate

Cold, with long winters

Warm and sunny, with high summer temperature

Main application

Northern regions

Southern regions

Low-E glass vs. Standard clear glass

Parameter

Low-E glass

Standard clear glass

Energy efficiency

High: reflects thermal radiation, reducing energy loss and easing the load on heating and cooling systems

Low: allows heat to pass freely, increasing heating and cooling costs

UV protection

Reflects up to 99% of ultraviolet rays, preventing fading of furniture and finishes

Provides almost no UV protection for the interior

Cost

Higher due to advanced coating technology, but pays off through lower energy bills

Lower upfront cost but leads to higher long-term energy expenses

Appearance

Nearly indistinguishable from regular glass, maintaining clarity and natural light

Completely transparent, without a reflective effect

Long-term value

Significant: increases home energy efficiency and resale value

Minimal: does not affect energy efficiency or property value

FAQ

How can I know if I have low-E glass?

If you hold a match or lighter flame to the glass and one of the reflections has a different color (a bluish or greenish tint), then you have low-E glass. However, for safety reasons, it is best to verify the specifications on the packaging or the website.

Does low-E glass have a tint?

Yes, but it is barely noticeable. This tint does not affect the transparency of the glass or the appearance of the door.

Can low-E coatings be added to existing glass doors?

No, because low-E coatings are applied in a factory.