It’s common sense isn’t it? You change your old, drafty windows, with brand new Charlotte vinyl replacement windows and, as long as they are installed and caulked right, you can be assured that they are airtight, right? Unfortunately, in a lot of cases, that couldn’t be further from the truth. But I think that if you looked through the vast majority of manufacturers marketing materials you’ll see some reference to a item aspect of their window promoting it’s airtightness.
How do we know it’s not spot on? In rides the NFRC to the rescue. If you have the opportunity to go to their website ( https://nfrc.Org/label.Aspx) and read through it you’ll find out something very out of the ordinary. As opposed to the majority of the other figures on that label, Air Leakage, or Infiltration is not required to be published on the sticker. It is completely left up to every manufacturer as to whether or not they record their air leakage numbers on the decal.
Why is this critical? According to the EPA, windows are the biggest culprit when it comes to air leaking into, or out of the domicile. As a matter of fact, the Department of Energy estimates that a 1/16″ gap anywhere around a window is the equivalent of taking a brick out of the side of your home. How many windows do you possess in your home? Air leakage is the eminent equalizer when comparing otherwise similarly performing window products. The finest analogy is this…If you have a tire with three holes in it, and you plug two of the holes,what have you got? That’s right…A FLAT TIRE! If you have a product with the greatest frame and finest glass that leaks air like a sieve, what have you really got?
So the real question is…What is the lone purpose a manufacturer would decide not to record their Air Leakage/Infiltration number on their NFRC sticker?