How to Install a Window Air Conditioner

Installing a window air conditioner is an easy way to keep your cool.

Every editorial product is independently selected, though we may be compensated or receive an affiliate commission if you buy something through our links. Ratings and prices are accurate and items are in stock as of time of publication.


With the summer temperatures on the rise, you may need to install that window air conditioner — it’s easier than you think.

Tools Required

  • Scissors
  • Screwdriver

Materials Required

  • Appliance cord
  • Foam weatherstrip
  • Window Air Conditioner
  • Wood block

Project step-by-step (5)

Step 1 - What type of window do you have?

  • First, look to see what type of window you have. Window air conditioners fit best in single- and double-hung windows that slide vertically.
  • Casement windows that crank open and horizontal sliding windows don’t work as well for window air conditioners.
  • If you have a storm window, you may need to remove the screen or slide open the lower window.

Step 2 - Blocking

  • When installing the window air conditioner, you want to make sure it’s sitting level in the window opening.
  • You made need to add some blocks between the windowsill and the air conditioner near the front (and possibly toward the back) to assure that the unit is level. Typically, a 2x4 works well for this, but every situation is different.

Step 3 - Weatherstrip

  • Before moving forward, you'll want to seal around the window. Cut, peel and stick 1-1/4-in. x 1-1/4-in. foam weatherstrip to the windowsill, as well as on top of the air conditioner or to the bottom of the window.

Step 4 - Install the air conditioner

  • Some window air conditioners are quite heavy — you may need a helper.
  • With the window open, lift the air conditioning unit into the window opening until the wings are even with the window jamb, centering it in the opening.
  • Lower the upper window down on top of the air conditioner, holding it in place.
  • Expand the air conditioner wings to close the gap on each side.
  • (Optional) If you don’t mind putting holes in your window, secure the wings to the window.

Step 5 - Electrical Connection

  • If possible, plug your air conditioner into a designated 20 amp circuit.
  • If you need to run an extension cord, it's always a good idea to use a heavy-duty appliance cord.

Post a Comment