When we saw an AC unit in the wall of a vacation rental in Key West, we knew it was a solution for our home office. The downside of using a portable air conditioning unit, designed to fit in a window opening, is that it prevents opening the window in mild conditions for natural cooling. By building a unit into a wall, you can free up the window for operation and have a permanent installation.
This works particularly well for cooling a small addition or part of the house that isn’t cooled naturally. When a unit is mounted high on the wall, it does a good job of cooling the space efficiently and effectively. A key requirement is to place it near a 115-volt electrical outlet, or have one added near the location on the wall. That electrical work requires a professional installation, which will cost about $250.
In addition, a carpenter will install a 10,000 BTU energy-efficient air conditioner into a wall for $1,140, which includes the labor, framing material and unit. If you have carpentry experience, you can do carpentry work for $540, the cost of the unit and framing material, and save 53 percent. Inside you’ll have to cut away enough of the interior wallboard to frame in the opening with molding. You may have to repair and paint the walls and trim if you damaged them during installation. To complete the job outside, trim out the opening with molding to finish the opening on the exterior.
Pro Cost—DIY Cost—Pro time—DIY Time—DIY Savings—Percent Saved
$1,140—$540—5.5—8.5—$600—53 percent
