How to Install Ductwork for Over the Range Microwave Ovens

Ventilate an over the range microwave oven to keep your kitchen clear of smoke, steam and odors. Most over the range microwaves come with an exhaust adaptor to connect into a duct system. The ductwork runs through the wall, connecting into a wall cap or roof cap to ventilate the air to the outside of the home. Using as many straight duct pieces as possible and limiting the amount of elbow pieces keeps the airflow unrestricted, preventing blockages.

Things You'll Need

• Ductwork pieces
• Duct tape

Instructions

1. Place a transition piece onto the microwave's exhaust adaptor, usually located on the back or top of the appliance. The exhaust adapter is usually a rectangular-shaped piece of metal on the outside of the microwave. The transition piece has a rectangular side and a circle side. The rectangular side attaches to the adaptor.

2. Press a piece of duct tape around the bottom of the transition piece to seal the two parts together.

3. Fasten the wall template, included with over the range microwaves, on the wall where the microwave will hang. The template outlines the location where the brackets for the microwave should be installed and where to cut into the wall to place the ductwork.

4. Press the tip of a drywall saw into one edge of the ventilation lines on the template. Push the saw through the wall. Move the saw slowly in and out along the ventilation lines until the drywall piece releases from the wall.

5. Position ductwork pieces over the transition piece. The configuration varies with the amount of space and the shape of the space between the interior wall and the exterior wall or roof cap.

6. Press a piece of duct tape around the bottom of each ductwork piece to seal the pieces together.

7. Slide the end of the ductwork onto the end of the roof cap. If you can reach the roof or wall cap from inside of the wall, wrap a piece of duct tape around the cap and the ductwork to seal it. Or access the cap from outside of the home. Climb onto a ladder to reach the cap. Pull the ductwork slightly through the wall of the home's exterior. Wrap the tape around the cap and ductwork and push the cap back into the wall.

8. Apply an even layer of caulking around the outside of the wall or roof cap to keep airflow restricted to within the ductwork.