Reducing heat loss with window coverings
Transparent vinyl sheeting sealed to the inside of a window frame with clear polyethylene tape provides good insulation and light transmission at low cost. But installing and removing the sheets every season can be a chore; they must be replaced periodically, and you can’t open a sealed window. Cheaper polyethylene film, sold by the square foot or in storm-window kits, is less effective than vinyl and lasts only one season.
Pop-in shutters made of foam insulation board overlaid with fireproofed fiberboard are inexpensive and easy to make. Cut to fit tightly inside a window frame, shutters insulate better than plastic and, covered with fabric, are more attractive. Daytime storage. however, can be a problem. Hinged shutters solve the problem by folding back against the wall.
Insulated roll-up shades are available ready made or as kits. Running in tracks mounted on the window frame, shades are nearly as effective as foam panels, but can be expensive.
To prevent heat loss, close shades or install shutters before sunset. To avoid cracking window panes on very cold mornings, remove the insulation before turning on the heat.