Air infiltration is a big deal, and the most energy efficient windows are equipped with features such as weather-stripping, heavy duty airlocks, and other features to block out drafts. To add perspective, consider that the industry average cfm rating of .30 allows the equivalent of 24 soda cans of air per minute of cold air transferring through your windows in the winter. Compare that to Soft-Lite at just .8 soda cans of air per minute, the lowest air infiltration rate in the industry. If windows account for 10% of air leakage in a home, it’s important to have the lowest air infiltrated window on the market.