Window air conditioning systems don't always form a perfect seal with the surrounding window. This means that some of the cold air ends up outside while some hot air comes inside. Spray expandable foam is a great way to fix this problem, but is a mess to remove. So direct application of the foam isn't a great idea for window units that will only be in the window for part of the season. Here are a few methods for insulating a temporary window air conditioner that will make the unit easy to remove for storage or service.
Expandable Foam and Plastic Bags
If appearance isn't of utmost importance to you, it's possible to still use the expandable foam without spraying the foam directly on the unit or window. Stuff some small plastic bags like a grocery bag into the holes between the unit and the window where you need added insulation. Make sure the bags only have the opening hole and no small holes on the underside. Point the end of the spray foam into the bag and spray. Quickly tie the open end of the bag shut so the foam doesn't expand out onto your carpet. Repeat until the unit is fully insulated.
When you remove the unit, you can simply pull out the bags and discard them.
Foam Strips or Board
Head to your local home improvement store and look for insulating foam strips that are made to seal up the cracks around windows. The strips have an adhesive on them that is sturdy but designed to be removed at a later date. Follow the package directions and use the strips to insulate the unit.
If you can't find the strips, or the gaps around your AC unit are wider than the strips, you can look for foam board at the store. You can then cut that board to size and use a temporary adhesive spray to attach the self-made strips around the unit.
Use the package directions on the strips and adhesive to remove the insulation before removing the window unit.
Clear Window Insulating Film
If appearance is a major factor in your decision, and your cracks are fairly small, you can pick up a clear window insulating film kit at the hardware store. To apply the film to a full window, you essentially press it on the glass, smooth out the surface, and then use a blow dryer to shrink the plastic and affix it to the glass. You can use a similar method for insulating your window unit. You simply need to cut the film into strips first.
Read the package directions to find out how to remove the film when the time comes. Usually, using the edge of a scraper to peel up one end is enough to get you started on peeling off the whole strip.
For more information, contact an air conditioning company like Perry Heating Cooling.