How to Install a Reverse Cycle Air Conditioner

Location

• 1

  Determine the wall on which you want to install the reverse cycle air conditioner. Reverse cycle wall units must mount on a wall that connects directly to the outside.

• 2

  Determine an approximate location for the indoor wall unit based on clearance specifications provided in the installation manual. Mitsubishi wall mount reverse cycle air conditioners, for instance, require clearance of approximately 3.3 inches from walls and at least 70 inches from the floor. Mark the approximate location on the wall with a pencil. Use a step ladder if necessary to access very high areas of the wall.

• 3

  Find the studs in the wall on both sides of the approximate location marked for the air conditioner, using a stud finder. Mark each stud with a pencil.

• 4

  Place the wall mounting plate for the air conditioner against the wall, lining up the mounting brackets on each end of the plate with the wall studs. Drive a screw through one of the mounting brackets on the wall plate into the stud behind it.

• 5

  Align the plate on the wall in a perfectly horizontal position, using a level to check for flatness at the top, bottom and middle of the plate.

• 6

  Drive a screw through the other bracket of the wall plate into the stud behind it after leveling the plate.

• 7

  Measure a distance approximately 12 inches from the bottom of the mounting place, using a tape measure. Mark the area with a pencil.

• 8

  Locate the studs on either side of the mark drawn below the wall plate, using a stud finder.

• 9

  Cut all drywall from the mark to the floor, from wall stud to wall stud, away from the wall, using a drywall knife. Make shallow cuts to avoid slicing into electrical wiring or pipes behind the drywall.

• 10

  Inspect the area behind the drywall to ensure that it is free of electrical wiring and plumbing pipes. If so, continue with installation. If not, choose another area to mount the air conditioner.

Assembly and Preparation

• 11

  Assemble the piping at the back of the air conditioner, which generally entails manually fitting a rubber hose over the outlet on the back of the air conditioner. Follow installation manual instructions for this step.

• 12

  Assemble the conduit designed to connect the wall unit to the small outdoor unit that draws warm air into the house. Follow manufacturer's instructions, which usually require little more than manually attaching lengths of piping to one another.

• 13

  Locate the area on the wall through which you must pass the piping from the back of the air conditioner. Wall plates usually possess a semicircular recess in one bottom corner to provide a guideline for this hole.

• 14

  Mark an outline of the hole on the drywall, using a pencil. Base the dimensions of the hole on the diameter of the conduit. Measure the conduit diameter with a tape measure.

• 15

  Cut the hole in the wall using a drywall knife.

Installation

• 16

  Pass the conduit through the hole cut in the drywall, so the end of the conduit sticks through the wall at the bottom of the wall plate and the rest hangs within the wall frame, between the wall studs from which you hung the wall plate.

• 17

  Hook the conduit up to the back of the air conditioner by placing it over the rubber hose extending from the back of the air conditioning unit. Attach any fasteners provided by the manufacturer.

• 18

  Mount the air conditioner on the wall plate by sliding it into place. Wait for all parts of the air conditioner to audibly click into all mounting mechanisms before letting go.

• 19

  Extend the conduit in the wall to a distance specified by the installation manual. A Mitsubishi conduit, for instance, should extend the full distance of the wall unit to the floor, or at least 70 inches.

• 20

  Hold the end of the conduit against the wall sheathing, or wood boards located behind the wall studs. Trace the outline of the end of the conduit on the sheathing using a pencil.

• 21

  Cut a hole in the sheathing for the end of the conduit using a power saw. Cut all the way through siding on the other side of the sheathing, until your each the outside.

• 22

  Install a thimble around the hole. Thimbles are square pieces of metal with a circular hole in the center used for passing piping and vents through walls. Mount the thimble by attaching it to the wall sheathing with screws provided by the thimble manufacturer. Fit the hole in the center of the thimble through the hole cut for the conduit.

• 23

  Pass the end of the conduit through the hole in the center of the thimble.

• 24

  Go outside with the exterior portion of the air conditioner. Locate the end of the conduit protruding through the wall.

• 25

  Place the exterior portion of the air conditioner in an area that satisfies clearance specifications provided by the manufacturer. Place the unit on top of scrap wood or cement blocks to satisfy ground clearance requirements.

• 26

  Attach the conduit to the appropriate inlet on the exterior unit, following manufacturer's instructions.

Finishing

• 27

  Apply weatherproof caulk to the exterior wall around the hole cut for the conduit.

• 28

  Go inside. Apply weatherproof caulk around the exterior of the thimble.

• 29

  Apply drywall adhesive to the perimeter of the large section of drywall removed from the area below the wall plate.

• 30

  Place the drywall back into the wall. Wait for the drywall adhesive to dry before applying drywall mud or paint to the seams of the drywall to reintegrate it with the structure of the wall.

• 31

  Plug the unit in. Individual reverse cycle air conditioners that consist of nothing more than a wall mounted unit and an outdoor unit can plug directly into an outlet via an extension cord -- they do not require direct connection to a circuit breaker.