Everything to Know About Energy Efficient Windows and How They Work

Everything to Know About Energy Efficient Windows and How They Work

If you’re interested in reducing your carbon footprint this year, one of the best ways to achieve this with your home is through energy-efficient windows. However, those new to the area are probably reading this first sentence with some confusion. What are energy-efficient windows? How can windows be energy efficient? Here’s everything you need to know. 

Emissivity in Glass

If you give your window a little knock right now, you’ll notice that it’s made of traditional glass. The first difference with an energy-efficient window is that it uses what’s called Low-E glass. What does this mean? Low emissivity. Essentially, the role of this glass is to block the sun’s rays. At the moment, the sun blasts down in the summer, and most of this heat passes through your standard glass windows and enters the home. Suddenly, you’re sweating while trying to watch TV in the living room and need to put the air conditioning on to stay cool.

By installing windows that block the sun’s rays, your living room stays much cooler, and you shouldn’t need the air conditioning as much in the summer. Ultimately, this helps to reduce your carbon footprint (as well as helping your wallet!). When you aren’t relying so much on the air conditioning unit, you can put this money towards days out with family or another important cause. Depending on what you’re trying to achieve, you’ll find energy-efficient windows with one, two, or even three panes. 

Naturally, plantation shutters in Melbourne provide the best protection against the sun’s rays. Thus, your house stays cool in the summer and warm in the winter (you’ll see why the second half of this statement is true in the next section!). Some manufacturers also offer reflective coatings and tints for the windows. How effective is Low-E glass? Most manufacturers promise to block around 90% of the sun’s rays. Yet, you’ll find some that go beyond this and promise up to 97%. However, if you were to compare this with traditional glass windows, they tend to block around 20% of the sun’s rays. 


While Low-E glass gets most of the attention with energy-efficient windows, it’s a two-pronged approach, and the second prong regards insulation. First, look at a traditional window, and you’ll see that metal is responsible for the insulation. However, you probably don’t need reminding that metal isn’t an effective insulator. 

Fortunately, energy-efficient window manufacturers replace the metal insulation with urethane or polymer structural foams. Not only can these foams expand to insulate when it’s needed the most, but they also keep heat loss to a minimum. You’ve seen how the window allows your living room to stay cool, but now it’s also helping to remain warm in winter too. As less heat passes through the window and escapes outside, you don’t need the heating on for as long in the colder months. Elsewhere, you’ll find some energy-efficient windows that use krypton, argon, or another gas to expand when needed to prevent heat loss. Either way, heat bounces back into the room rather than escaping outside. 


While low emissivity glass blocks the sun’s rays from entering the home in summer, better insulation keeps more of the heat inside your home in winter. Then, of course, you aren’t so reliant on the air conditioning and heating systems, and you help the planet while paying less for energy bills each year. Everybody wins!