How to Install a Window-Mounted 24000 BTU Air Conditioner

Prepare the window unit for installation. Some units require that you remove the control knobs and the front panel to slide the air conditioner condensing unit out of the case. Not all units require this step for installation.

Peel the tape off the top rail gasket. Center the gasket over the screw holes on the top of the unit case. Press down to secure the gasket in place. Attach the top mounting rail to the top of the gasket, lining up the screw holes. The rail goes on with the open lip facing the back of the unit so that the smooth side of the rail is facing the front of the unit. Use four small Philips screws to secure the rail in place.

Assemble the accordion panels. Some accordion panels require you to slide the side rails on the left and right panels before attaching to the unit case. Once the accordions are ready, attach the side rail for each accordion panel to the side of the window unit case using three small Philips screws on each panel.

Open the window where the air conditioner will sit. Measure the length of the window. Make marks on the windowsill so the unit will be centered in the window. Peel the tape off the window sash sealing gasket. Attach the gasket to the bottom of the open window. Press into place to secure.

Slide the case into the window. Close the window down on the top rail to hold the case in the window. The window fits into the lip on the backside of the top rail. Pull the side accordion panels out and attach to the side of the window frame with one flathead screw on each side. Drill 3/16 inch pilot holes in the windowsill to secure the bottom of the unit case to the windowsill. Use the smaller flathead screws to secure the case to the windowsill.

Attach the mounting brackets to the bottom of the case on the outside of the window. Place the left bracket on the left side of the case on the outside of the case. Line up the holes. Use the bolt and nut to secure the bracket to the case. Do the same on the right side. Use an adjustable wrench to move the bottom bolt on the bottom of the bracket so that the bolt is tight against the house.

Attach the window locking bracket to the top of the open window and the window frame with two Philips screws. This stops the window from opening any farther and keeps the window securely held in the top rail.

Slide the air conditioner condenser in the window-mounted case. Replace the front panel and knobs. Cut a foam strip the width of the window. Push the foam down in the gap between the open window and the top window so no drafts or bugs get into the house.