Window A/C
By: Amanda Campbell
Updated: March 3, 2011
If you’d like to install your new air conditioner through the wall, you’ll need to keep a few considerations in mind:
Site selection:
When choosing a site for installation, choose an exterior wall. Make sure the wall does not have wiring or plumping that will be disturbed when you cut an opening in the wall.
For personal safety, the unit must be installed in a place where there is a grounded electrical outlet within four feet. Your air conditioner will be equipped with a 3-prong grounding plug. Don’t use an extension cord. Check with a qualified electrician if you aren’t sure if an outlet is grounded.
Make sure there is adequate wall support to hold the weight of the air conditioner. Units typically weigh between 90 and 178 pounds.
Don’t install the air conditioner in an area where the front panel will be exposed to a heat source that could raise the temperature of the surface panel.
Tools You Will Need:
- Electric drill and a 3/32” or smaller bit
- Flat blade screwdriver
- Level
- Gloves
- Safety Glasses
- Utility Knife
- Tape Measure
- Saw
- Wood Preservative
- 1” or heavier lumer
- Six #8x1/2” wood screws
Installation:
Measure the height and width of your air conditioner. On the wall where you are going to install the air conditioner, mark the dimensions plus twice the thickness of the wood you will use to build the frame.
Cut the opening in the wall. Again, be sure not to cut through any electric wiring or plumbing.
Build a wood frame to line the opening. Make sure the frame the unit sits on is constructed of lumber that is at least 1” thick.
Apply wood sealer to the exposed outside surface.
Insert the frame into the wall opening. Square and level the frame before nailing it into place.
Position the cabinet into the wall opening. The top of the cabinet should extend ˝” into the room. If we use trim, then the cabinet should extend ˝” past the trim.
TIP: Tilt the cabinet to the outside so any water will run to the outside.
Use a level to make sure the cabinet is level side-to-side. First, place level inside the right side of the cabinet. It should tilt to the outside approximately ˝ bubble for proper drainage. Check the left side, too.
Use insulation to seal the opening between the cabinet and frame.
Attach the cabinet to the wood frame with wood screws.
TIP: Don’t over-tighten the screws or the cabinet will distort, disturbing the seal between the cabinet and the air conditioner—making your AC less energy efficient.
Slide the AC into the cabinet. Reattach the ground wire with the ground screw. Make sure the ground wire is pointing straight up. Put any excess ground wire between the coil and the air conditioner cabinet.
Insert the front tab of the front panel into the top of the cabinet and swing the front into place. Attach the bottom of the panel with front panel screws.
Caulk outside wall openings around the cabinet.
Add trim around the interior and exterior for a nice finished look.
Cool off after a job well done!


