How to Install a Microwave Hood Fan

Unplug your current exhaust fan. Disconnect the ducting to the exhaust fan. Remove the duct tape with a utility knife. Unscrew the small screw securing the exhaust adapter to the straight duct with a screwdriver.

Remove all mounting hardware; this varies from unit to unit. Open the cabinet above the exhaust fan and check for bolts or screws on the bottom shelf of the cabinet. Remove the front grille and check for screws extending to the back of the unit. Completely remove the exhaust fan.

Determine the center space between the cabinets, below where you are installing the microwave hood fan, with a tape measure. Mark the center line with a carpenter's level.

Find the studs with a stud finder. Mark the studs with a pencil on the wall with the help of a carpenter's level.

Secure the microwave hood fan's mounting plate to the wall with the screws provided and a drill. Secure the mounting plate into a stud in the wall. Verify that the mounting plate is level.

Tape the template to the bottom inside of the cabinet, according to the manufacturer's directions. Drill holes through the cabinet according to the template with a drill and drill bit.

Secure the damper and duct adapter to the microwave with the screws provided and your drill. Verify that the damper moves freely.

Test-fit your house duct over the damper adapter. If the house duct is not the same size as the adapter on the microwave hood fan, attach a transition adapter--such as a rectangular-to-round adapter. Verify that the damper still moves freely. If it does not, adjust as necessary.

Remove any contents inside of the microwave--such as a glass plate, and set them aside.

Raise the microwave unit into the designated area with a partner. Feed the cord into the hole in the top cabinet. Attach the unit to the bottom of the lip on the bracket by hand, then tilt it into its area.

Fasten the screws provided to the microwave unit. Have a helper hold the unit in place and secure the screws to the microwave unit through the top of the cabinet holes using a drill.

Slide the house duct into or over the adapter or transition adapter according to the specific adapter.

Wrap electrical tape around all connections, verifying that every joint is thoroughly sealed.

Install the grease filters according to the manufacturer's directions. Turn on the microwave unit and test.