Installing a Window Air-Conditioner


Before installing the air-conditioner, make sure the window is sound. Repair any rot and damage. If the paint is peeling, repaint. Ideally, the window you choose should be near the center of the room and shaded from the afternoon sun. If you must choose between one or the other, choose shade.

Put the air-conditioner in a window near an outlet, or install a new outlet so you can avoid using an extension cord.



  • Drill and bits
  • Level
  • Screwdriver
  • Scissors / Utility knife( to cut weather stripping)


  • Air-conditioner
  • Angle brackets
  • Foam weather stripping
  • Wood screws / Sheet-metal screws


Step 1

Step 1: Install the mounting bracketsInstall the mounting brackets, if anyHeavy and older window air-conditioners may have a bracket that screws to the windowsill. Screw it in place using sheet-metal screws on a metal frame and wood screws on a wood or vinyl frame. Put a level across the bracket and sill, and adjust the bracket as needed to level it.

Step 2

Step 2: Place the air-conditioner in the frame or windowPut the air-conditioner in the frame or windowIf there is a frame, move the accordion panels aside and slide the air-conditioner in. If the frame is built-in, open the window a bit wider than necessary to make it easier to put the air-conditioner in place. Close the window to hold it in place.

Step 3

Step 3: Slide the accordion panels back in place so that they are tight against the air-conditionerSlide the accordion panels back in place so that they are tight against the air-conditionerSecure the mounting frame and panels as directed by the manufacturer. If you’re driving screws in a new location, drill pilot holes first, using a bit slightly smaller than the diameter of the screw.

Step 4

Step 4: Screw the angle brackets to the upper sash as directedIf the installation kit that came with your unit contains angle brackets, screw them to the upper sash as directedThe brackets keep the weight of the air-conditioner from forcing the window open. If
there aren’t any brackets, buy and install ones that are similar to that shown here.

Step 5

Step 5: Fill the gap in lower sash with foam weather strippingBecause the lower sash is partially open, there is a large gap between it and the windowFill the gap with the foam weather stripping that came with the unit or buy some at your nearest Home Depot .

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