This allows for a replacement unit which might be larger.
Install a window air conditioner in the wall.
Your appliances should also have come with an installation guide that you can tape onto the wall and trace its outline.
Build a jamb box of 1 6 pre primed pine about 4 inches wider and 4 inches taller than the air conditioner required.
Then measure the width of your through the wall air conditioner and transfer that measurement to the wall where the studs were marked.
Once the window air conditioner is secure take some final steps to help keep the warm air outside and the cool air inside.
Use a stud finder to locate two adjacent stud bays that will provide enough room for the opening.
Remove unit front cover and screws that hold the unit inside its case.
Install the case or sleeve into the opening.
Once you locate 3 4 wall studs mark them on the drywall with an x using a pencil.
Secure the side panels with screws.
Window air conditioners often come with a foam insulating strip.