Replacement windows vary widely in cost and quality. There are many replacement windows out there to choose from, and everyone claims to have the best and be the best. So how do you as a consumer cut through the hot air and determine what is the best choice for you and your budget?
One of the ways to to cut through the fluff and get to the hard facts is to look at objective test data on the replacement window you are considering (read here for more info). We encourage all home owners looking for replacement windows to make sure your salesmen give you test results from an unbiased third party such as AAMA or NFRC. If they can’t, or won’t, or they do not have an AAMA certified window you should probably rule them out right there. When looking at test results there are a few different ratings we recommend you look at and one of the most neglected is air leakage (AL).
Air Leakage in replacement windows is referring to the amount of air that infiltrates and exfiltrates through the seams in the window due to air pressure differences between the indoors and outdoors. Replacement windows with moving parts, locks, etc. are more prone to leakage than a picture window is because there are more seams for air to move through. The most energy efficient replacement windows and homes will control the air movement and keep conditioned air in, and unconditioned air out. So air leakage in a window is important because it’s an indicator of how well the replacement window is going to perform in saving you money and keeping your home comfortable.
Air leakage is also a good indicator of the quality of the replacement window. A high quality replacement window with tight tolerances, good design, sufficient weatherstripping, etc. will seal better! A poor quality window, made with cheap materials, and with poor design will not seal well. It’s that simple! You may save a few hundred bucks on the price of a window today, but what is that replacement window going to cost you over the next 10 years as it more freely lets air move through it? Unlike SHGC and Uvalues; air leakage is a year round impact in hot and cold climates and seasons. It’s not something you want to be unaware of in your replacement windows project.
The standard for air leakage in replacement windows is .30 cfm or below. Average replacement windows will be somewhere in the .15 range (give or take). High quality replacement windows will be .10 or lower, and that is where we recommend you be if budget allows. Ultra Windows has the Soft-Lite Elements replacement windows with a .01 air leakage! That’s about 15x better than the competition.
In addition, to the quality of the window, the quality of the installation can play a big part in replacement windows air leakage ratings. More on that later….so stay tuned!