Kitchen Exhaust Fan Goes Into Attic

The kitchen vent fan must exhaust directly to the outside not into an attic crawlspace or a space between floors.

Kitchen exhaust fan goes into attic.

The duct should be smooth and straight with as few bends as possible. If it sits on an inside wall venting through the attic and out is a better option but if it is on an outside wall it is more practical to vent through the wall. The exhaust fan makes a lot of noise but doesn t move much air bad ducting of kitchen exhaust reduces the air flow just as it does with bathroom exhaust fans. Several different ways you can move that hot air to the outside.

Small diameter ducts could trap grease creating a fire hazard. And these ultra modern high efficiency ul listed range hood vents of which you speak are going to terminate inside the attic inside of site built wooden boxes. No it s never a good idea to have any exhaust fan in your home dump all that hot moist air in your attic. The duct should exhaust air to the outside of the building through the roof or through an exterior wall and not into the attic or crawl space.

It is definitely not a good idea to vent a range hood into the attic. The best exhaust fan venting is through smooth rigid ducts with taped joints and screwed to a special vent hood. The range hood has a low capture efficiency unfortunately you can t go out and comparison shop based on this metric. Connect the ductwork with sheet metal screws wrap the connections with aluminum faced duct tape then wrap the attic part of the duct work with an insulated sleeve.

It can cause you a lot of problems with mold and mildew forming on the underside of your rafters and decking as well as getting into your insulation. The outlet needs to be at least 10 feet from any window or other air inlet and it must be covered with a louver screen or grille. Run duct work through the attic then attach the stove vent to a roof cap. In either case do not vent into the wall or the attic.

Although this isn t always possible in attic crawl spaces you should always insulate the duct to prevent condensation problems. The duct for your exhaust fan needs to be run to the outside of the house to remove the chance of a fire hazard. If you allow the air from your bathroom exhaust fan to mix with the air in your attic which is usually the same as the outside temperature it can cause condensation wetting the wood allowing for mold growth and over time weakening the structure of your home while causing possible health issues for your family. Ideally the range hood should be vented to the outside usually through the roof.

Screw the ductwork together. You can find 4 in. Duct already wrapped in insulation at home centers.