How to Plumb Air Conditioning Units

Measure the size of the air conditioning unit and the window opening to ensure that the unit will fit into the space provided. Check the window frame and sill to ensure that they are strong enough to hold the screws that come with the unit.

Pull on a pair of gloves. Remove the air conditioner from its cabinet by removing the front panel screws with a screwdriver, then removing the air filter. Grasp the front handles of the unit and pull it straight out from the cabinet. Set the air conditioner aside. Install two angle brackets on the outer window sill to hold the air conditioner by drilling guide holes for the bracket screws. Screw the brackets into place, then adjust them so that the unit will have a slight outward tilt to provide good water drainage.

Slide the window filler panels into the retainer slots on each side of the unit. Drill two guide holes with a hand drill on the inner bottom of the window sill. Drill two guide holes on each side of the window frame for the window filler panels. Set the cabinet onto the angle brackets. Screw the top angle rail and the extended window filler panels on the cabinet into the window frame. Fasten the top of the cabinet to the angle rail with screws.

Tug on the cabinet to ensure that it is screwed firmly into place. Remove the adhesive backing on the window sash seal, then place the seal between the upper and lower sashes to block air flow. Screw the safety lock into place with two screws on the upper right corner where the upper and lower sashes meet.

Remove the adhesive backing on the bottom rail seal. Press the seal into place along the bottom rail of the unit. Replace the air conditioner in the cabinet, and put the air filter and front panel back on. Plug the unit in.