Drill a 1/2-inch hole to create a starting point for the saw blade. Cut a 10 1/4-inch hole in the base of the cabinet and the subfloor directly beneath using the reciprocating saw. Ensure these holes are centered directly underneath the cooktop's downdraft extension.
Cut a section of vent pipe to fit over the end of the cooktop's vent extension underneath the motor of the unit. This piece must also extend through the floor and 6 inches beneath the subfloor.
Slide the elbow adapter over the piece of vent sticking through the subfloor.
Route a section of vent pipe from the elbow to the nearest exterior wall. The pipe should also be routed in between the joists, away from pipes and electrical lines if possible.
Drill a 1/2-inch hole as a sawblade starting point. Cut a 10 1/4-inch hole in the exterior siding of the home. Slide the exterior vent piece over the end of the protruding vent pipe from the outside.
Wrap two turns of metal duct tape over each pipe joint. Caulk the gap between the exterior vent and interior of the home, if present. Apply two passes of duct tape over this connection between the exterior vent and pipe.
Things You Will Need
- 10-inch metal duct
- Reciprocating saw
- 1/2-inch drill bit
- Elbow adapter
- External vent
- Metal flash/duct tape
- Metal shears
- Silicone caulk
- Always keep ductwork as short as possible to maximize ventilation.
- Try to create as few joins as possible. Use single longer lengths of pipe instead.