Measure the window opening and confirm the AC unit fits
Gather the AC unit, mounting hardware, and any included side panels
Open the window fully
Install the mounting bracket if the unit requires one
Place the AC unit on the window sill or bracket
Center the unit in the window opening
Lower the window sash onto the top of the unit to hold it in place
Extend the side panels to fill the gaps
Secure the side panels to the window frame
Tighten all screws and fasteners
Make sure the unit is level or slightly tilted outward
Seal any remaining gaps with foam or weatherstripping
Plug the AC unit into a grounded outlet
Test the unit to confirm it runs properly