If you live in a hot climate, energy efficiency needs to be in the forefront as you choose new windows for your home. Windows are the biggest source of heat transfer in most homes. In a hot climate, this means more heat enters your home through the windows than through the doors, walls, or roof! Choosing the most energy-efficient windows possible will help keep your home cooler so your air conditioner does not consume as much energy. Here are three things to look for when choosing your windows.
One of the biggest sources of heat, of course, is the sun's rays. While you don't want to stop that bright sunshine from making your home feel cheery, you don't want the heat that it brings. Low-e glass is the perfect solution. This type of glass has been coated in a special, metallic coating that causes heat waves from the sun to bounce off of it. In other words, the heat from the sun's rays is reflected back towards the outdoors rather than being allowed to penetrate the glass and enter your home. You still get to enjoy the light from the sunshine, though!
The metallic layer on low-e glass is very thin, so low-e windows look exactly like normal glass windows. The "e" in low-e stands for emissivity, a measure of how much heat actually penetrates the glass. Normal glass has an emissivity of 0.84, which means 84% of heat waves travel right through it. The best low-e glass windows have an emissivity of 0.02, meaning that only 2% of heat waves travel through them. This is a big difference!
Today's windows are almost always constructed of two or three panes of glass. Between the panes of glass, there's a thin layer of air, which acts as an insulator and helps further reduce heat transfer into your home. In the most energy-efficient windows, however, this air is replaced with argon gas. The argon is an even better insulator than air, so very little heat will be transferred through windows of this type.
You may also see windows filled with krypton gas. These cost significantly more than those filled with argon gas and may be a good choice for people in very cold environments, but when you live in a hot environment, they're usually considered over-kill.
There's more to a window than glass. The material that surrounds the glass is also important to consider. Years ago, wood was often used to make window sashes. Today, you can find vinyl and aluminum sashes. The most energy efficient choice, however, is composite sashes. These sashes are made from a mixture of wood fibers and concrete. They help keep heat out of your home in several ways:
- Composite sashes are more insulating than vinyl or aluminum sashes, so less heat travels directly through them.
- Composite sashes are less likely to warp with age, so you don't get gaps between the sash and the window where warm air can leak in.
- Composite sashes fit tightly within a window frame, so less air seeps in between the sash and the frame.
Composite sashes come in many colors and styles. Some look like natural wood, and others come in brighter colors like green or rust. So you can enjoy this energy-efficient material regardless of the style of your home.
If you opt for low-e windows with argon gas filling and composite sashes, your home will stay much cooler all summer -- and your energy bills will be more manageable. To learn more about these and other efficient window options, speak to a window replacement company, like Energy Star Construction, in your area.