How Do You Duct a Kitchen Exhaust Fan?
There are two big goals to achieve where possible when thinking about kitchen exhaust venting and ducting: 1) use as short a distance as possible to the outside to maximize airflow out of the kitchen, and 2) keep the path straight as possible to reduce trapping or build-up of grease in the ducting. Most homes tend to vent directly to the side wall and outside, but some one-story homes tend to go straight up towards the roof and out, letting heat rise quickly. In more modern homes the stove and cooking area vent tends to be right above the cooking area, but this unfortunately eats up valuable cabinet space doing so. However, one does need to make sure the length of the exhaust system for a kitchen ducted exhaust fan doesn’t exceed the power and capacity of the fan involved.
Again, plan the route of the ducting first and which way it will go moving exhaust away from the cooking area. That means clearing the space behind and above where the exhaust will work and pull air from. A lot of the specific design will depend on how a home is set up structurally, so there’s not one set plan for everyone.
If you’re going to go upward and out the ceiling, then the best way to confirm your ducting path will be to use a small guide through the internal drywall ceiling into the attic. This is easily done by just attaching a straightened metal coat hanger to a drill and inserting it through the drywall. You can then see in the attic if the hanger wire is near or blocked by any of the attic joists. There should be a sufficient clearance anywhere around where the duct hole will go upward through, depending on the duct diameter. From here, the roof is next and then to the outside. If you’re not sure how to do this exactly, a roofer might be a better option.
Now you can easily cut through any cabinets needed for the ducting to travel through. Place the face for temporary location siting and then remove it so you have free space to install and position the ducting. Don’t forget a duct sleeve in the attic portion if you’re in a region that sees a lot of frost. The ductwork pieces will attach together with sheet metal screws. Once assembled, make sure to seal the seamwork between parts with heat resistant duct tape (i.e. aluminum faced type). With the ducting finished, you can now place the hood over the cooking area, connect it, and finish the fan installation.
If your home or facility is the type that does a lot of cooking, you may want to consider a dual approach with an immediate hood fan and an inline fan. Continental Fan multi-purpose inline fans make a great choice with lots of options for power and sizing. A single hood fan can get overworked trapping all the grease and becoming a big mess. Double capacity moves the exhaust up and out efficiently, compensating for your heavier cooking.
Visit Industrial Fans Direct to shop our collection of kitchen exhaust fans for commercial and residential applications!