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Air Leakage: How It Affects a Window’s Energy Efficiency

Remember, a one-size-fits-all approach won’t work in choosing a new energy-efficient window. Everyone knows you should look for an ENERGY STAR® certification, but how do you pick one from dozens of windows that have that label? You look at its U-factor, solar heat gain coefficient (SHGC) and air leakage rating (AL) ratings.  

What the AL Rating Means 

The AL indicates the amount of air that can pass through a square foot of a window. A window with an AL of 0.1 lets in the least amount of air while a window rated 0.3 lets in the most amount of air. However, this doesn’t mean you should avoid windows with a rating that’s more than 0.1 – as long as the AL is below 0.3, the window can be considered energy-efficient. 

Here’s a tip: if you’re looking for a window with a low AL, try looking for double-pane replacement windows

How Does It Affect Your Home’s Energy Efficiency?

Of course, drafty windows, ones with a rating of more than 0.3, can raise your power costs; heat and air-conditioned air can leak out of your home, forcing your HVAC unit to consume more power to maintain a comfortable temperature inside. 

How to Pick the Right Window 

However, keep in mind that although a window’s AL is an important aspect, it isn’t the only one. When evaluating window performance, you need to factor in its several other features. One feature can’t make a window entirely energy-efficient. Our energy-efficient windows have a variety of features like Fibrex® frames with excellent insulation capabilities and ultraviolet-blocking High Performance™ Low-E4 glass. 

One more thing: make sure only a qualified company installs your new energy-efficient windows. Installation errors can leave behind gaps, which can then let in drafts. 

Renewal By Andersen® of St. Louis, an independently owned retailer with an A+ rating from the Better Business Bureau, offers a wide variety of premium windows and doors. To schedule a free consultation with one of our design specialists, call us at (314) 983-9977, or fill out our contact form here. We serve homeowners in Chesterfield, MO, as well as other nearby areas.

Reviews

"Scheduled for December, Installed in October, High quality windows and Excellent install team. I haven't seen people work together like that in years. I am definitely impressed."

Raymond Mills
Oct 13, 2022

"The service provided by Renewal by Anderson is great, both on the sales and the installation side. Our sales representative was very accommodating and helpful. The installation crew was efficient and they all were professional. These are really nice windows and a great upgrade especially from builder-grade windows."

Brad Allen
Nov 17, 2022

"It is great to do business with a company that still cares about what they do and respects the end goals. We appreciate your craftsmanship professionalism, and cannot say enough about the wonderful experience. It was clear from the onset of the installation we got the A Team and we certainly appreciate that."

1speedwagon
Nov 17, 2022

"Everyone I worked with from setting up the initial appointment to the salesman to the installers to everyone who checked on us and kept us updated on the progress of the windows was courteous, professional, and responsive. There’s always someone who is willing to answer your question without jumping through hoops which is rare these days! The installers were on time, did a beautiful job, cleaned up the space better than I expected, and even helped me with some blinds I couldn’t remove and fixed my squeaky front door! I’ve already recommended Renewal by Anderson to friends!"

Karen Mortillaro
Nov 19, 2022

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