Winter is cold enough on its own, but add to it the chills from a drafty window, and you may feel like you're living in the Antarctic. Follow these easy steps to learn how to insulate a window against winter.
Find the drafty window. If you're just going to insulate a few drafty windows in your home, you'll first need to locate the draft. You can do this two ways. You can either have a friend blow a blow dryer around the edges of your windows from outside while you feel for any heat coming in. Or, you can hold a flame from a lighter carefully around the edges of your windows to see if the flame flickers. If it does, you've got a draft and this window will need to be insulated.
Purchase a window insulation kit. Your local home improvement store will sell window insulation kits (3M makes a great one). Check the box to see how many windows each box will insulate, and then purchase as much as you need. These are one-time use packages, so you will need to purchase them each you decide to insulate a window against winter.
Shrink wrap the window. Your window insulation kit will come with shrink wrap. It's a clear, cellophane-like material that has great insulation properties. To attach this to the window, first apply double-sided tape to all of the edges of the window. You don't want any gaps, so take care to ensure the tape has no gaps in it. Attach the shrink wrap (or film) to the tape carefully. You only get one shot at this, as the tape will be very sticky, so make sure you apply it exactly where you want the film to be. The film should be taut with no wrinkles. Press your finger around the edge of the window to secure the film to the tape. Next, use your hair dryer to shrink the film. The heat has the capacity to melt the film, so it's important to keep the hair dryer moving at all times. Once the film is heated, it will shrink and all wrinkles should disappear.
Trim the excess. Once you have insulated the window against winter, you can trim any excess film that goes beyond the tape. A utility knife or a good pair of scissors will do the trick. Just be sure not to cut into the shrink-wrapped area, or your insulation will be useless.
You may wish to insulate both the inside and the outside of your window against winter. While this is overkill, you may notice a difference. However, most window insulation kits only need to be applied to the inside of the window to be effective in insulating a window against winter.