A Homeowner's Guide to Low-E Glass: What is it and How Does it Work?
Posted on September 12, 2022 in Pella Windows & Doors of Nashville
Glass has become one of the most popular building materials in Tennessee homes today. Because of its modern appeal and versatility, many Nashville homeowners incorporate it in the design of their houses, whether it be in the form of windows or doors.
Besides its impact on a home’s style, it also improves the thermal and solar performance of the structure. But how does glass accomplish this? The answer is simple: Low-E coatings.
If you’re not familiar with Low-E coatings and how they work, don’t worry; our Pella of Nashville experts will walk you through everything you need to know about this material.
What Is a Low-E Glass Coating?
Also known as Low Emissivity Glass, this type of material has a special coating that makes it more energy efficient. Originally developed to store infrared light indoors in colder climates, Low-E glass is a cost-efficient and effective thermal solution to keep the temperatures of your indoor surroundings more comfortably regulated.
To accomplish this, this material uses an ultra-thin, non-toxic, and colorless coating that minimizes the amount of ultraviolet light entering your home. This can substantially improve indoor lighting and reduce your heating or cooling costs, making it one of the most practical and beneficial materials to have in your home. Whether you’re building a new house or thinking about upgrading your existing one, consider incorporating Low-E glass into your design plans.
Different Types of Low-E Glass Coatings
Before you can enjoy the benefits of this material, you first need to familiarize yourself with the different types of Low-E glass available in the market today. Currently, there are two main categories of this product: Hard Coating and Soft Coating.
Hard coating — also known as passive Low-E coating — is manufactured through a pyrolytic process or a plasma deposition process, which produces a pyrolytic coating that is then applied to the material. When applied, it fuses to the surface of the glass, creating a strong and permanent bond. This type of coating makes the glass very durable and long-lasting.
On the other hand, soft coating — also known as solar control Low-E coating — is manufactured through a process known as Magnetron Sputtering Vapor Deposition (MSVD) or Cathodic Vapor Deposition. During this process, metal particles like silver are deposited on the surface of the glass in a vacuum chamber to create a Low-E coating that can effectively transmit high levels of sunlight and divert solar energy. As a result, this energy-efficient glass can prevent heat from escaping through your glass panels and even reflect more heat into your home.
How Does Low-E Glass Work?
By now, you know that the main function of a Low-E glass is to store heat, improve lighting, and reduce ultraviolet rays that enter your Nashville home. So how does it work?
The emissivity of the glass radiates energy that allows it to reflect the heat back inside without allowing the external temperature to affect or alter it significantly. The applied coating prevents the heat from your home from escaping through the glass’ pores, thereby protecting the warm temperature.
To put it simply, think of your Low-E glass like a thermos; a thermos has a built-in lining that keeps the temperature of your beverage relatively stable. This happens because the lining constantly reflects the heat in the container back and forth. Since Low-E glass has a similar composition, the same concept applies.
The Best Low-E Glass Features
When a Low-E coating is very effective, it performs well in four major metrics: the U-Value, the Solar Heat Gain Coefficient (SHGC), the Visible Light Transmittance, and the Light to Solar Gain. We’ll dig into what each of these mean so you can make sure your Low-E glass is doing as well as it’s supposed to:
- U-Value: This is a rating system given to windows by measuring its insulating characteristics to determine how much heat loss is occuring.
- Solar Heat Gain Coefficient (SHGC): The SHGC dictates the amount of solar radiation entering your home through your glass windows or doors. The lower the SHGC, the lower the amount of solar heat is transmitted.
- Visible Light Transmittance (VLT): This is another rating system that measures how much visible light waves are transmitted through the material. Generally, a good Low-E glass should have about a 42% VLT.
- Light to Solar Gain (LSG): This is the ratio of VLT to SHFC. The higher the ratio, the more sunlight is entering your house. A high ratio means that your indoor lighting is good, which conserves energy.
Switch to Low-E Glass Windows
With its ability to improve lighting, conserve energy, store heat, and lower ultraviolet impact, incorporating Low-E glass into your Nashville home can save you plenty of money in the long run.
This type of material can save costs, protect your home from UV damage, and ensure your comfort in your home. If you want to elevate your living conditions and promote sustainability, we recommend replacing the glass in your windows and doors with Low-E glass.
More questions about windows? Read more information from our Pella of Nashville experts. Or, you can schedule a free in-home consultation for one of our Pella professionals to discuss your door replacement options with you and answer any questions.