How To Install A Through-The-Wall Air Conditioner in 10 Easy Steps

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This quick guide will show you how to install a through-wall air conditioner easily and on your own.

It’s not as hard as you might imagine, but it will take a little time and effort to get the job done correctly.

So let’s get to it!

Why Own a Through-The-Wall Air Conditioner?

You should skip this part if you’ve already purchased an air conditioner.

But if you’re in the research stage and want to know what’s involved in installing this type of air conditioner, this section is for you.

Through-the-wall air conditioners have become popular during the last few years.

These units used to be cheap and unreliable, but they now rival window air conditioning systems and central air conditioners for installation, cooling capacity, price, and energy efficiency.

Through-the-wall air conditioners offer the following benefits:

1. Energy Efficient

through the wall air conditioner

Standard size through-the-walls don’t use much energy to run. It keeps your bill low and gives you more money in your pocket.

Most homeowners pay around $20-$30 per month to operate an air conditioner.

2. Permanent Solution

These appliances are built into a permanent, out-in-the-way solution for your air conditioning needs.

The problem with other types of air conditioners like portable and window air conditioners is that you have to move and store them, which often damages the unit.

3. Dual Role as a Heater

Some through-the-wall air conditioners provide both heating and cooling. This offers year-round comfort at the lowest upfront cost.

Tools & Materials You WiIl Need

through the wall air conditioner

Before you install your AC, you need to gather the right tools together.

Here’s a checklist of the stuff you’ll need to do this job right: 

  • Installation Sleeve (also called a “bracket”. This part should be added to your order. If not, then be sure you buy one.
  • Caulk Gun
  • Paint
  • Hand Saw
  • Measuring Tape
  • Silicone Caulk
  • Pry Bar
  • Stud Finder
  • Drywall Compound
  • Circular Saw
  • Several 2” x 4” lumber studs
  • Utility Knife
  • Drill and bits
  • Hammer
  • Level
  • Nails
  • 1 sheet of drywall
  • Drywall Knife

Step 1: Choose a spot in your wall to install

through the wall air conditioner

Look around the room where you’d like to install an air conditioner through the wall and choose a location for it.

Try to avoid spots where it will have a large visual impact.

Make sure your location has access to an electrical outlet so that you can plug the system in after installation.

Make sure the base of the air conditioning unit is at least 1 foot above the floor.

This reduces the dust the air filter catches from the floor and prevents moisture from building up.

Step 2: Mark the Wall Studs

Wall studs are used to support walls, and they’re usually 16 inches apart.

Once you’ve picked a location, you’ll need to mark the studs, so you know where you’ll be able to cut through the drywall later.

You want to keep your number of walls to be removed to a minimum.

You have two choices here:

  • Use a stud finder to find the stud holes precisely.
  • When you tap on the wall, you’ll see a point where the sound becomes solid. Next, hammer a thin penny into the wall to verify where the best spot is if you hit a stud, good. If not, try it again.

Once you’ve found 3-4 studs, mark them on the wall with an ‘X’ using a pencil.

Measure the width of your air conditioning unit and then mark the wall where the stud was located.

You should get an installation manual and template for your air conditioner to trace its outline on the wall.

If not, use the sleeve (bracelet) for this purpose.

Make sure you set the sleeve or guide paper correctly so that you can cut within the fewest numbers of studs.

Step 3: Turn the Room's Power Off

through the wall air conditioner

Find your house’s electrical panel (breaker box), and turn off the breaker that controls the electricity to the room.

You will be cutting into the wall in another step. You don’t want to cut into electrical wires and get shocked accidentally.

If you need to power your drill and saw from another room, run an extension cord between two rooms that still have electricity.

Step 4: Cut the Hole

Use the provided guide sheet or sleeve to trace the outline of the AC’s opening on your wall.

Ensure your outline is level by using your leveling tool during the marking procedure.

Make another outline 2½ inches longer than the current one. This will give you sufficient extra room to create a supporting frame for the system out of the 2 x 4 lumber pieces.

Cut out the outline using your drywall knife. And score vertical lines across the top of the wall studs.

Use a hammer to drive the middle of the scored drywall segments so that they come out.

Alternatively, you can use a hand saw to remove the drywall pieces instead of a hammer.

Remove the drywall pieces so you can see the wall studs.

If the wall is insulat­ed, cut out the pieces to match the opening you made in the wall.

Step 5: Cut the Wall Studs

With a circular saw, cut through the wall studs inside the wall opening so that they are flush with the outline.

Step 6: Build a Frame for the Air Conditioner

through the wall air conditioner

Measure the opening’s width and mark that measurement onto two pieces of wood. Cut those pieces of wood into equal lengths.

Estimate the wall opening height and subtract the thickness of the 2 x 4’s you cut. Cut them down to the length that fits best.

Put those four pieces of 2×4 lumber together to form a frame. Put them all together.

Slide this 2 x 4 frame you made into its wall opening and fasten the frame in place by fastening it into the wall studs.

Step 7: Cut a Hole In Your Outside Wall

Make sure the weather is not too wet or snowy before working on the wall. If you don’t, you might introduce water into the wall.

Cut a hole in the inside frame that touches the outside walls. These holes will be a guideline for where to cut out the exterior walls.

Using your level and pencil, draw four lines to connect these drill holes outside the building.

With the circular saw, cut out the outer material so that there is an ideal fit between the inner and outer hole.

Step 8: Install the air conditioner unit

through the wall air conditioner

Push the metal sleeve through the wall opening and fasten it according to the instructions.

Insert the device into its sleeve and fasten the bracket onto it.

Plug the power cord into the nearest power outlet.

Step 9: Complete the Installation

Use a fresh drywall board to cut and patch any vulnerable areas around the appliance before installing it. Use drywall screws to nail it in place.

Use a drywall knife and compound to fill any gaps or holes.

Paint and prime the walls so that they match the current wall color.

Use the silicone caulk and caulking gun to place a thick bead of caulk near the edges of the device on the home’s interior and exterior. This will prevent any air from flowing into or out of the house.

You can install moldings or trim around the AC units to give your air conditioner a more finished look.

Step 10: Turn the Power Back On

through the wall air conditioner

Turn the breaker off so the electricity starts flowing into the room.

Next, turn on your air conditioning unit and enjoy its cooling effects!


You can see that the installation procedure is not difficult – as long as you have all the necessary tools and materials available and follow the correct steps to protect yourself and your wall from damage.

A through-the-wall air conditioner is an excellent and inexpensive option for cooling a room without spending too much money.
It also looks so much nicer than a window unit!

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