How to Install a Microwave with External Venting

Many times an over-the-range microwave that recirculates cooking fumes can be converted to exhaust to the outside.

Here’s how to go about it:

  • Remove the access plate on the top of the unit in order to reach the motor.
  • Remove the motor mounting screws on the back of the oven.
  • Take out the motor and rotate it 90 degrees, so that the fan motor now blows upward.
  • Attach the transition piece to connect the oven to ductwork
  • Modify the cabinet over the stove to allow the duct to pass through by cutting holes on the top and bottom.
  • Use a laser measuring tool to mark a dot on the ceiling that will identify the center of the hole that needs to be cut for the ductwork.
  • Join the sections of ductwork and seal the joints with metallic tape to secure them.
  • In the attic, mark a spot directly above the duct so you can cut a hole in the roof decking and extend the vent pipe up through that opening.
  • On the roof, tuck the flange of a roof vent under the shingles above the opening and secure it with roofing tacks and roofing sealant.
  • To hide the exposed duct in the kitchen, build a frame around it and cover it with cabinet grade plywood. Cover the exposed edges of the plywood with corner trim.
  • Apply a coat of primer and two coats of the wall paint.

Watch the video for details.

Further Reading