How to insulate a window with heat shrink film and a hairdryer

This guide shows you how to add a cheap double glazing layer to a single window using heat shrink film, double sided tape and a hairdryer. It suits renters and anyone on a budget who wants to keep heat in during winter. You only need basic tools and about 20 minutes per window.

How to Install 3M Window Film Insulation (Ecobob.co.nz), by Ecobob on YouTube. 1 min 39 s.

Video length
1 min 39 s
Time to do it
20 minutes
Difficulty
Easy
Steps
8

What you need

Steps

  1. Clean the glass and frame with window cleaner and a cloth, then wipe the frame with alcohol so the tape sticks well.

  2. Measure the width and height of the window, then cut the shrink film 5 cm wider and 5 cm longer than your measurements.

  3. Run double sided tape around the whole window frame, not the glass, and press it firmly with your fingers.

  4. Peel the backing off the tape a little at a time so the film does not stick in the wrong place.

  5. Press the top edge of the film onto the tape, then pull the film gently down the sides and along the bottom, resticking until it sits evenly.

  6. Run the back of a spoon along every taped edge so the film bonds fully to the tape.

  7. Hold a hairdryer on a warm setting about 10 to 15 cm from the film and move it slowly across the window until the creases tighten and the film looks clear like glass.

  8. Trim the extra film along the frame with scissors, cutting carefully so you do not nick the film you want to keep.

Tips and common mistakes

Buy an extra roll of double sided tape, since running out halfway leaves you with a half sealed window.

Keep the hairdryer moving. Holding it still in one spot can melt or tear the film.

Never rest the hairdryer on the film or frame, and unplug it when you finish.

A warm room helps the film shrink smoothly, so fit it on a mild day rather than in a cold draught.

Questions

Can I use a normal hairdryer on high heat?

Use a warm setting rather than the hottest one and keep the nozzle moving. Most kits are made for a standard hairdryer, but too much heat in one spot can melt the film.

Does the film go on the glass or the frame?

It goes onto the tape on the frame. The film sits slightly away from the glass, and that trapped layer of air is what insulates the window.

How long does the film last?

A season or more if the tape is pressed down well. Peel it off in spring and wipe the frame to remove any sticky marks.

This guide was drafted from the video's details and general task knowledge. It has not been checked against the full video. Check the video and relevant product instructions before following a procedure. Report a correction.

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