How to Install a Ductless AC on an Interior Wall

Oct 29, 2022

How to Install a Ductless AC on an Interior Wall

While the mysteries of how to install a ductless AC on an interior wall are best left to professionals, some Canadians choose the DIY route. You’ll still need an expert to deal with the refrigerant lines. However, you can mount the interior wall unit and call for help later.

Ductless AC is exactly what it sounds like, an air conditioning unit without the ductwork. It includes an indoor and outdoor unit with refrigerant tubes and electric wires running between them. They usually cool a single room, or small space, rather than an entire home.

Wondering how to install a ductless AC on an interior wall? Follow these steps.


Select the Right Wall


This is a critical part of the job, as you need to ensure, the wall you select can be fitted from inside and outside the house to connect via refrigerant tubing. You also want to choose a wall big enough for the air handler to sit, without bookshelves or TV stands getting in the way.

Avoid spots opposite windows or near fireplaces as you don’t want the handler in direct sunlight or near heat.


Find Studs


You can’t learn how to install a ductless AC without learning how to find your wall studs. Wall studs are the vertical frames in your walls. They are usually spaced out between 16 to 24 inches apart. The plate should be mounted into the studs for a strong hold. Use a stud finder and make sure there are no unforeseen obstructions like wiring or pipes in that wall before you start drilling.

Mark the studs for the handler installation. It should be installed 6 feet up from the floor to the bottom of the handler.


Use a Level to Install Brackets


Ductless AC installs use brackets to hold up the internal unit. Brackets need to be level, or the unit can’t drain properly. This could cause it to malfunction or use more energy trying to cool your room.

Using a level and a measuring tape, mark off where the brackets will go with a pencil. Take a step back and make sure everything looks right before proceeding.


Get Ready to Drill


Check the screws you’ll be using and select a drill bit a little smaller. Drill pilot holes for the screws. Pilot holes help guide the screws into the spaces they need to go to secure your unit.

Now comes the scary bit. You need to drill a pilot hole toward the exterior of the home on a downward angle for optimal draining. A hole saw bit is best for this job.


Connect Wires and Mount


Now, all that’s left is to connect control wires by opening the back panel. Your unit should have instructions for this. The refrigerant pipe can be pushed through the hole you made toward the exterior of the house and held in place (for now) with electric tape.

Mount the indoor unit on the brackets you installed, pushing wire and tubing through the refrigerant hole. Now it’s time to call a professional to help with the rest.


Call a Professional


The split ductless AC installation process is tricky and requires some carpentry and electric skills. To avoid damaging your home, or causing injury to yourself, we advise calling in a professional HVAC team to help you with your ductless AC installation.


Have questions for our HVAC experts regarding a ductless AC installation? Contact our team today.