How to Replace an AC Unit in a Mobile Home

Remove the old unit from the window. Have someone help you; some older units weight as much as 100 lbs. and can be difficult to move by yourself.

Inspect the window sill. Look for signs of wood rot or splitting. If you see any, you will need to replace the sill before installing the new unit.

Install the brackets from the mounting kit. Follow the manufacturer’s instructions for how far apart to space the brackets. Typically, you need to measure the window sill to find the center of the window space, and then mark the sill with the pencil at that center point. Measure off the distance to each bracket from the center point and mark them. Screw the sill portion of the bracket directly into the window sill with 2-inch screws. Check the portion of the mounting bracket attached to the window sill with the level to ensure it isn’t leaning into or away from your home. Once it is level, screw the external bracket into the side of your home. Do the same for the other bracket.

Pick up the new AC unit and slide it out of the window from the inside of the mobile home and over the brackets. The bottom of the unit will catch onto the brackets and stop it from moving further. Have someone else hold onto the unit while you go outside and attach it to the bracket by inserting a screw up from the underside of the bracket.

Lower the window until the bottom of it rests on top of the AC unit. Screw the angle bracket that comes with the installation kit into the window to keep the sashes in place. Pull out the expandable panels on the side of the unit and screw them into the sides of the window frame. These both secure the unit and seal off your home from outside air. Install any weather stripping that came with the unit according to the manufacturer’s instructions.

Apply a bead of caulk around the exterior of the unit. The caulk prevents moisture from damaging your mobile home by seeping in around the AC unit.