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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

"We had a large picture window and two side windows replaced. Everyone from the person who took our order to the installers were top notch. We got exactly what we wanted. Granted, we had to wait a few months, just like you do for everything these days, but we were told that up front. The windows were well worth the wait. We've replaced windows before by going to home maintenance stores. Don't waste your money on those. Our Renewal by Andersen windows look great, they operate like a dream, and are worth every penny. Quality through and through."

C. Roberts Owens | RbA of St. Louis, MO - Maryland Heights

"My new windows look great!! I can feel the difference in my house and my furnace is no longer staying on constantly. My installation crew was polite, tidy and speedy. It couldn't have went better"

D. Holland Schneider | RBA OF ST. LOUIS, MO - MARYLAND HEIGHTS

"The workmen were very professional and did a great job. Cleaned up everything. I am very pleased with the new windows. Beautiful!"

B. Young | RBA OF ST. LOUIS, MO - MARYLAND HEIGHTS

"From start to finish everyone we dealt with were total professionals.. The project process was well communicated, the installers did an excellent job and the windows - I’m so excited about our new windows! They look great. I can’t believe I’m saying this but I am looking forward to cleaning them. And it was obvious immediately that the insulation is vastly better than the old windows. Also, I am just a customer who gets nothing for this endorsement. I just appreciate good service and an excellent product. This company knows how to do it right."

B Stewart | RBA OF ST. LOUIS, MO - MARYLAND HEIGHTS

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