Window Energy Efficiency Parameters

Energy ratings are essential when it comes to buying windows. It is one of the top things buyers evaluate. There are a few prime reasons why people are looking to replace their current windows. It might be that the windows are old and damaged, a lot of noise coming from the outside and more. At the top of the list of issues that lead to window replacement is window air infiltration or seal failure.

In most cases, people are just looking at the most common features, like the u-factor and solar heat coefficient. These ratings are very important since they are the science behind insulation and heat loss. They are the parameters that help measure the window energy efficiency. However, future window buyers often overlook air leakage ratings because they never think that their windows will be letting air in or out. But we cannot stress enough how air leakage is one of the most important factors to consider when buying a new window. 

What is Air Infiltration and Air Leakage? 

Air infiltration is another way to say air leakage. It is the measurement of air that passes through the window assembly itself. This number is determined before the windows are installed. To make sure that you have the best results, the windows need to be professionally installed to reduce any air infiltration. 

It is natural to assume that your new windows will get rid of your air leakage problem. That is true, and even more so if you select the right window replacement company.

Nonetheless, as a good saying goes, nothing is perfect, and that includes your brand-new windows. Although not perfect, this does not mean that your windows will allow a significant amount of air into your home. Air can infiltrate your home easily in many ways, windows have many parts and not all new windows are created equal, so before you invest in the new windows make sure you are selecting the best option. 

How to Calculate It?

Air leakage has different levels on a scale of 0.1 – 0.3, with 0.1 being the least amount of air that will trespass the window. If you are in the market for a new window, the best air infiltration friendly windows will be vinyl windows with dual pane. Those are excellent at keeping air out of your home. Also, make sure the company you are buying from displays all energy ratings. If they only display one, they must be lacking in others. The most common ratings are u-factor, air infiltration, and solar heat gain coefficient. 

The Best Rated

The NFRC is an independent non-profit organization that establishes an objective window, door, and skylight energy performance ratings to help you compare products and make informed purchase decisions. 

A Perfect View, we only use the best rated windows, so for window replacement, contact A Perfect View Construction at (951) 698-2885.


The American Architectural Manufacturers Association (AAMA) has a history of industry leadership and the development of window and door performance standards. Windows installed by A Perfect View Construction carry the AAMA Gold Label to show they have met their strict requirements, which are tested and certified by a third party. This rigorous testing includes water penetration, air leakage, structural integrity, and Forced Entry Resistance.

For window replacement contact A Perfect View Construction at (951) 698-2885.