How to Prevent Cold Air Draft From the Cooking Range in Winter

Unscrew and take down the screen cover on the vent hood. Shine a flashlight up into the vent. Inspect the duct flap, and pull it closed if it is stuck open. Duct flaps typically stick open due to a buildup of grease. If this is evident, use degreaser and a sponge to clean the inside of the vent and duct flap.

Examine the external duct cap on the outside of your house; this might be on a wall or on the roof. If the flap is stuck open, push it closed and remove any debris that is causing it to stick. If the hinge seems sticky, spray it with a silicone spray lubricant. If the flap is missing or in disrepair or you have a duct without a flap, replace it with a self-flashing duct cap. A duct cap with a felt seal is most effective at preventing cold air from seeping in.

Ensure that the seam where the external duct meets the roof or wall is well sealed. Apply a new bead caulk around the seam if necessary.

Insulate any uninsulated vent pipes that run through your attic by spraying on aerosol insulating foam. Wear long sleeves, gloves and a face mask when working with aerosol foam.

Check all vent pipe joints where two sections of vent pipe are connected or where vent pipes are connected to pipe elbows. Make sure they are properly sealed with professional duct tape. Remove any worn or damaged duct tape. Seal the joint seams with professional duct tape.