08 Dec What about low-e window coatings in the desert?
Stellar Glass Installs Energy Efficient Windows
We were featured in the latest write-up in Home Energy Pros about low-e coatings on windows in the desert heat and we’d like to pass that on to our viewers here on the site.
In this article we explain what low emissivity is, how it works, and when low-e is the right thing to do for your home. Low-e coatings reduce the amount of ultraviolet and infrared light that passes through glass in your windows without compromising the amount of visible light that passes through as well. The ultraviolet light we’re talking about is what causes things to fade. While infrared light, or heat energy, is where the heat comes from the sunlight into your home and then radiates off the walls and windows themselves. Which is what usually leads the high electric bills and makes it so hard to keep your home cool in the summer.
What is low-e?
When the sun hits the glass in your windows, the heat energy in its rays are either reflected off the glass or absorbed and then transmitted into the interior space by the glass. A materials ability to radiate energy is emissivity. Materials that are highly reflective have a low emissivity because they do not absorb and radiate heat energy. A dark colored shirt, for example, has a high emissivity because it will absorb and radiate the heat. Low-e windows, then, naturally reflect the heat energy from the sun and keep it out of your home, which is a good thing. Where we always pause, is where is that heat energy being reflected to… if your windows reflect that energy directly onto something like a lawn, or your vehicle you’re going to scorch those materials and over time the sun’s harsh rays will scorch them. So, we have to be smart and think through all the details before installing low-e coatings onto our windows.
Depending on their emissivity and the temperature of their surface, all windows will radiate heat. It’s why double and triple pane windows are so popular because of their insulating properties to both, reduce the temperature of the interior window, as well as the wall surfaces around it.
How does low-e work?
Low-e glass works in two ways, it reflects the heat off the windows and keeps it from entering a space, but also keeps the interior heat of space inside where you want it by improving a window’s insulating properties. The low-e coating is a microscopically thin, transparent coating, thinner than a human hair, that reflects heat. During the winter, when the cold winter tries to suck out the heat energy inside your home, the low-e coating reflects the heat back inside, reducing much of the heat loss that happens through glass. Likewise, during the summer, the heat that’s trying to come through your glass through the sun’s rays is blocked in a sense and reflected off the glass, away from your home. Where double and triple pane windows come into play is that the space between your double pane or triple pane windows are filled with Argon or Krypton gas and insulates your windows to keep the surfaces cooler, or warmer during the winter. As a result, low-e windows and energy efficient windows work together to keep your rooms comfortable.
There are two types of low-e coatings to choose from: passive low-e coatings and solar control low-e coatings. For warmer climates, you want solar control low-e coatings because they keep the sun’s infrared heat energy out, making air conditioning more efficient and ac costs lower. While passive low-e coatings are good for very cold climates because they allow some of the sun’s heat energy to pass through the window and help heat the building during the winter, but still keep the interior heat energy inside.
Low-e windows are great when used properly. Low-e glass will keep your desert home cool in the summer and warm in the cold winter months. But only install low-e coatings where they’re truly needed and where they won’t do more harm than good. You don’t want to install them above your lawn or anything that can fade from sunlight. The sun wiill create dead spots in your lawn, kill plants, or destroy the hood or your vehicle. If you’re unsure about the type of windows you should use, the types of glass, or coating options you have then please give Stellar Glass Works a call. We’ll work with you and give you an honest evaluation of your home and what you need. Install low-e where it’s beneficial, double-pane windows where you can, and triple-pane windows when needed.
Choosing the right windows and coatings will play an important role in the overall performance of a window and can significantly affect the overall heating, lighting, and cooling costs of your home. For a free estimate call us today at (602) 679-8346.