How to Install an AC Unit in the Wall

An air conditioner, according to "Popular Mechanics," allows you to lower the temperature of the air in a room. Comfort levels can fall between 61°F and 86°F. Air conditioners can be permanently installed into an exterior wall. Installing an air conditioner unit in the wall may be desirable when there is no window in the wall or a specific positioning of the air conditioner is preferred. Wall air conditioners are a good choice when you want to cool one or two rooms.

An air conditioner can be installed in a wall through the window.
  1. Select the spot for the air conditioner on the wall. Hot air rises, so a good place for an air conditioner, according to "Consumer Reports," is 12 to 48 inches above the floor in the center of the room. A prime location for an air conditioner unit is below a window. Also, consider the proper electrical outlet with the correct electrical supply. Most air conditioners, according to "Good Housekeeping," either run on a 120-volt or 240-volt outlet. Check your air conditioner manual for the proper electrical receptacle. Make sure the electrical cord can reach the receptacle from your desired wall position.

  2. Measure the air conditioner unit to find out the wall hole size needed. Cut the rectangular hole with a utility knife to expose at least the width of the studs, and make it taller than the air conditioner unit. You will need room to install framing according to your air conditioner manual.

  3. Remove the insulation by cutting it with a utility knife.

  4. Install the wall framing according to the air conditioner manual. This is support for the air conditioner unit. Make sure the framing is plumb and level so the unit will drain properly.

  5. Cut through the exterior siding with a circular saw, using the inside hole as a guide.

  6. Mount the air conditioner sleeve into the hole in the wall. Check to make sure the sleeve is square and level. Attach the sleeve to the frame, according to the installation guide.

  7. Install the air conditioner into the sleeve. It is good to have two people for this job. Secure the unit to the sleeve with screws.

  8. Replace the insulation and drywall by cutting them to the proper size around the air conditioner.

  9. Caulk around the outside of the unit to seal air and water leakage.


  • Experience with construction and renovation is highly recommended prior to cutting into an wall.