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A/C Installation Kits for Side to Side Sliding Windows

Timothy Burns

Window mount air conditioners can be difficult to install. The heavy appliances never fits perfectly into the window opening, and in order to function well, the window must be sealed against the hot exterior air. When installing a window air conditioner into a sliding window, all the problems are rotated by 90 degrees, which can make the install more difficult to complete.

Air Conditioner Supports

Installing air conditioners in a sliding window can be tricky task.

The first thing you need to install an air conditioner in a sliding window is a device for supporting the air conditioner's weight. The heavy appliance hangs out the window, and will not balance well. Since a sliding window has a metal or vinyl track along the bottom of the window opening, home owners should use a metal support bracket. The bracket screws into the window frame, raises the AC unit above the track, and firmly supports the unit from front to back.

Sealing Around the Air Conditioner

Once the air conditioner is installed in the window, the rest of the window must be sealed against the hot, humid outside air. Apply 2-inch square foam tape around the perimeter of the air conditioner to seal off the bottom and sides. Then slide the window back toward the unit to close off the horizontal space. Then you only have the top area of the window to close off.

Enclosing the Window

Typical window air conditioners have sliding folded panels along the sides, because they are designed to install into double-hung windows that shut against the top of the unit leaving only a small space to either side to seal off. In a sliding window the open space is above the unit and you have two options. Some appliance stores have folding, expandable weatherproof panels. Find one of these panels which is the same height as the width of your air conditioner, turn it on its side, place it above the air conditioner and screw it in place at the top of the window frame. Alternately, cut a piece of plywood to fit the open space and screw it in place. While this second option is less aesthetically pleasing, it will likely create a better seal.

Portable Air Conditioners

If you are in the market for air conditioners, and have not yet made your purchase, consider a floor standing, portable unit. These appliances stand on the floor, and are about the size of a small microwave cart. The unit features a panel that slips into the window, attached to the air conditioner unit with two white flexible ducts. It is much easier to seal the panel into the window for the hot summer months than mount the entire air conditioner in a window opening. If the panel isn't the right size, a thin piece of hardboard or cardboard combined with duct tape around the perimeter will easily seal the panel into the window opening.