How to Install Window Air Conditioners in Walls

Check the manufacturer or owner's manual of your window air conditioner unit. The manual specifies whether your window unit can be used for a through-the-wall installation. If you are still uncertain, consult an HVAC (heating, ventilation and air conditioning) professional.

Find a suitable location to install the air conditioner. It should be installed near an outlet that can handle the voltage of your air conditioner. Most units require 120 volts, but there are some units that require 240-volt outlets.

Note the dimensions of the finished wall opening of your window unit by referring to the owner's manual. You need these dimensions to create an opening in the wall.

Use a measuring tape, pencil and straight edge to mark the dimensions you have noted on the wall location you have designated for installation.

Cut the drywall with a utility or drywall knife. Remove the drywall section.

Create a frame from the wall opening using plywood. Refer to the owner's manual for specific instructions and measurements for the frames. Framing the opening will help support the air conditioner unit.

Use a measuring tape, pencil and straight edge to mark the dimensions of the unit onto the external part of the wall.

Cut the siding and sheathing of the external wall using a circular or saber saw.

Install the slide-out chassis or the supporting frame of the air conditioner into the hole that you cut. Angle the chassis so it slopes downward, allowing the unit to drain properly.

Place the unit into the chassis, making sure the unit is properly secured inside the chassis.