Upgrading to Green Windows Part II – ENERGY STAR recommendations

In Part I of this blog series, we took a look at a couple of tips to convert your existing “non-energy-efficient” windows into energy-efficient ones without spending too much money. However, if you do have money to spend on replacement windows, by all means do so, but make sure you purchase the best ones for your home. One way to do this is to follow the recommendations of ENERGY STAR, which we’ll discuss in this post.
Just in case you’re not familiar with Energy Star, it’s a U.S. Environmental Protection Agency (EPA) project that helps businesses and individuals protect the environment by using energy-efficient products, and save some money in the process. The agency provides guidelines on what to look for when purchasing energy-efficient products and building materials, including windows.
According to Energy Star, windows gain or lose heat by:

• Air leakage around the window
• Radiation of heat into the home
• Direct conduction through the glass
Energy-efficient windows provide a solution to those problems. Precisely how much a window is able to control those factors is measured according to U-factor, Solar Heat Gain Coefficient (SHGC), and Air Leakage.
• U-Factor
U-factor determines the rate of non-solar heat flow being conducted by the window. When purchasing new or replacement windows, make sure that you find the lowest U-factor.
• Solar Heat Gain Coefficient (SHGC)
This measures how much solar radiation is transmitted through the window as heat. You’ll need to look for low SHGC ratings so that less heat from the sun goes through the windows.
• Air Leakage
This measures the rate of air leakage around the window. Naturally, you’ll need to find low air leakage rates when purchasing new or replacement windows.

You might be excited about purchasing energy-efficient windows, but there is one more thing that you should give importance to – installation. You’ll need to consider quite a number of things when it comes to installation and we’ll discuss some of them in the final part of this series, so stay tuned!