How to Insulate a Window AC Unit for the Winter

Window AC unit on red brick home.

Knowing how to insulate a window AC unit for the winter is one of best things one can do to keep heating costs under control once the thermometer starts to dip. With this type of air conditioning unit, there are two options when it comes to weatherizing the home: cover and insulate around the unit or remove the unit entirely and seal the window for the winter.

Insulating a Window AC Unit for the Winter

If you're unable to remove the window AC unit entirely from the window, you will need to insulate the unit to help keep the warm air from escaping the home. Weatherizing the window AC unit will also help extend the life of the appliance by protecting it from the damaging effects of the elements.

Insulate Around the Unit

Cut lengths of firm foam insulation sized according the height and width of the window unit. Use a putty knife to push the strips of insulation down into the tiny gap between the unit body and the window frame. Spray foam insulation can also be used; use it sparingly as the foam insulation expands tremendously.

Weatherize the Unit

Remove the outside cover from the window AC unit so that the inside components are exposed. Place a thick plastic garbage bag over the unit so it covers it completely and tuck the excess parts of the bag inside so it is fully sealed. Use duct tape to hold the bag in place if necessary. Once this is finished, reinstall the outside cover.

Cover the Unit

Most hardware stores sell heavy fabric covers made specifically to fit window AC units. These covers slide right over the outside portion of the unit and help protect it from seasonal elements like heavy snow, rain, ice or hail. Pick one up and cover your air conditioning unit to keep it safe and insulated all winter long. These covers are also good to have in the event of a very strong thunderstorm regardless of the time of year, just be mindful not to run the unit with the cover in place.

Removing and Storing the Unit for Winter

While taking the time to learn how to insulate a window air conditioning unit for the winter is a great way to help control your winter heating bills, nothing works as effectively as removing the unit outright. This allows you to close the window and seal it properly against winter's icy-cold touch.

The problem is that the job usually requires an additional pair of hands and handling a heavy air conditioner on a ladder can prove to be difficult and dangerous. Proper storage techniques are also important when removing and storing a window AC unit.

How to Store a Window AC Unit

If you want to ensure that your window AC unit is in operational shape come next summer, make sure you store it properly over the winter, not simply setting it down in an unused corner of the basement. The unit should be wrapped in a breathable fabric or covering and set someplace where it will not come in contact with the floor. The cooler fins and condenser lines are soft and can easily become bent if care isn't taken when storing the unit. Place the covered unit in a spot where nobody will accidentally pile anything on top of it.By learning how to insulate a window AC unit for the winter properly, you'll not only save on your heating and cooling bills; your unit will last significantly longer than you might expect.

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How to Insulate a Window AC Unit for the Winter