How it works
The film stretches across the inside of the window frame and traps a still layer of air between it and the glass. Still air insulates, and the film also stops drafts from the sash.
Installing
- Clean the frame where the tape goes with rubbing alcohol. Tape fails on dusty or greasy trim.
- Test the tape on a hidden spot first. Double-sided tape can lift paint, especially on old or freshly painted trim.
- Apply the tape to the frame, not the glass, all the way around. Press it down firmly.
- Hang the film loosely from the top, then the sides and bottom, leaving it a little slack.
- Shrink it with a hair dryer on high, moving steadily from the edges toward the middle, until the wrinkles pull out.
- Trim the excess with a sharp blade.
Removing it in spring
Peel the tape slowly at a low angle. Warm it with the hair dryer first if it resists. Rubbing alcohol takes off any residue.
Tips
- Do it on a dry day; humid air trapped behind the film can fog.
- Leave at least one window in each bedroom easy to open in an emergency.