How to Add an Air Conditioner Return Vent

Identify the location on your wall or ceiling where the return ductwork is located. Check to ensure the installation area has enough space behind the vents in case you wish to install return filters. Return filters improve the quality of air pulled through return air vents.

Hold the air return grille centered over the duct opening. Score the area around the frame of the return grille using a utility knife until it cuts through the drywall. Cut out the drywall using a saw, forming a hole that is approximately the size of the return grille.

Clear away remaining drywall and nails from the perimeter of the hole. Place the return so that it lays flat against the wall or ceiling surface, and sits directly below or in front of the air duct opening. Attach the end of the duct to the return grille using mastic sealant or metal tape. Sealing the ductwork at the return vent also will help prevent air leaks.

Insert brad nails or countersunk screws at the grille's drywall flanges, and fasten the return grille to the wall studs or ceiling joists. Look for the drywall flanges where the air return grille sits in the air return frame, or refer to manufacturer instructions.

Place the mounting frame provided by the manufacturer over the air return grille, which now is attached to the wall or ceiling. Insert and fasten countersunk screws into the installation holes located on the return grille's mounting frame.

Clean up leftover debris and smooth out the perimeter of the vent using drywall tape or spackle. Wait for the spackle to dry before finishing with matching paint or stain.