For several years, North Quabbin Energy has been promoting and teaching people how to make “winserts” – winter insulated window inserts that can help to reduce the heat loss in a typical window by up to 50%. The design has morphed over time, and the method illustrated and explained here is somewhat different from the one we’re using and teaching now.
The basic principle is actually quite a simple one, though: you need to build a frame slightly smaller than the interior dimensions of your window frame, cover both sides of it somehow with clear plastic, and attach some kind of compressible foam all the way around it so that it will fit firmly in place. The idea is that the two layers of plastic create a space of dead air that heat does not cross, making a thermal barrier and cutting down on drafts and heat loss. Many public and private buildings in and around the North Quabbin have added these over the years, and they can confirm that this simple technology really does work!
Click here to begin learning about winserts.