How to Install A/C Into a Brick Wall

Wall mounted air conditioners can be installed into any type of exterior wall.
Wall mounted air conditioners save window space.Wall mounted air conditioners save window space.
Among their advantages over window units is that they do not block useful window openings and views, they are not restricted by window size, they can be easily repaired and they do not require installation and removal as seasons change. Installing a wall mounted air conditioner in a brick wall requires some masonry skill and some specialized tools.

Step 1

Measure and mark the appropriate size opening on the interior side of your brick wall, according to the air conditioner manufacturer's specifications. Use your tape measure to size the opening, and use masking tape to mark the outline. Use your level to check that the tape outline is plumb on all sides.

Step 2

Use your power drill and masonry bit to make a pilot hole completely through the wall at each corner of the opening marks. These holes will serve as the guideline for your exterior cutting. Cut along the tape outline on the interior side of the wall with your circular saw and masonry blade.

Step 3

Move to the outside of the wall and connect the four corner holes with masking tape. Cut along the tape the same way you did on the inside of the wall. Use your small sledgehammer to knock the bricks out of the wall starting at the top. Break off any remaining pieces of brick, and make a smooth opening edge with your hammer and masonry chisel.

Step 4

Cut outward along the top edge of the opening with your circular saw. Make a 1/2 inch notch about 4 inches long on either side of the opening, at the very top corner where the side of the hole meets the top. Slide a steel lintel into the notch, and use your hammer to position it firmly in place. Apply mortar to both ends of the lintel and wait for it to dry and set according to the manufacturer's instructions.

Step 5

Slide the metal wall air conditioner mounting sleeve into and through the wall from the inside. Use your level to create the proper amount of outward tilt so condensation drips out and away rather than into your home. The air conditioner manufacturer will indicate the amount of slope required. Use your hammer and masonry nails to fasten the sleeve to the wall opening. Drive nails through the sleeve pilot holes and into the mortar joints between the bricks in your wall opening. These fasteners plus the extended lip around the inside of the sleeve will hold the unit in place.

Step 6

Place the air conditioner into the sleeve, and fasten it in place according to the manufacturer's instructions. Move to the outside of the wall and apply a thick bead of waterproof silicone caulking to the gap between the wall and the mounting sleeve. Plug the unit in and test it.

Things You Will Need

  • Tape measure
  • Masking tape
  • Level
  • Power drill
  • Masonry bit
  • Circular saw
  • Masonry blade
  • Small sledgehammer
  • Hammer
  • Masonry chisel
  • Steel lintel
  • Mortar mix
  • Metal mounting sleeve
  • Masonry nails
  • Waterproof silicone caulk

Tip

  • If you are installing a wall mounted air conditioner beneath an existing window, the opening will not require additional support. The window will already have a sturdy support framework that channels downward force around the hole and into the structure below. It is not necessary to install a lintel or a header above the air conditioner.

Warnings

  • Always wear work gloves and eye protection when cutting or chiseling brick or concrete. Shards can fly into your eyes and cause serious damage.
  • Use caution when installing your air conditioner into the wall. Should it fall, serious injury or death could occur.

About the Author

Robert Morello has an extensive travel, marketing and business background. He graduated with a Bachelor of Arts from Columbia University in 2002 and has worked in travel as a guide, corporate senior marketing and product manager and travel consultant/expert. Morello is a professional writer and adjunct professor of travel and tourism.