Upgrading Kitchen Ventilation during a Remodel
When you are planning your kitchen remodel, be sure you don’t overlook ventilation. If you don’t have a ventilation system, or if your system needs a lot of work, you have hours of work and much construction ahead of you to make things fit properly. But making these changes will be a good investment in the long run. For the best job and to have it completed in a reasonable time, hire a pro.
Whether you need to make minor adjustments to your ventilation or add or move ductwork, the fastest and certainly the easiest way to install ductwork is when the wall studs and ceiling joists are exposed, which is usually right after demolition.
When updating your kitchen ventilation system, you have three major concerns:
Locating existing ductwork: If your old kitchen had an over-the-range microwave oven or an exhaust hood, chances are good that you already have ductwork in place. The exception would be if the old exhaust hood was one that simply recirculated the air in the kitchen, only removing odors and not venting the air out of the kitchen.
The easiest way to check for existing ductwork is to open the doors of the cabinet located over the range. Any ductwork will be visible inside of that cabinet.
Fitting the old ductwork to the new appliances: If your kitchen does have ductwork, make sure that its current position will work with the new range hood or microwave oven. Look for the existing section of ductwork that is connected to the old vent hood or microwave oven. You’ll need to measure the length and the width of this section, called the boot. Exhaust boots are usually about 12 inches long and about 2 inches wide. You also need to check the boot’s location in relationship to where it fits inside the cabinet. If it’s away from the wall, you have some leeway to reposition the boot, if necessary. If it’s flush against the back wall, the new unit must have the exhaust opening in the same location or you’re in for a lot more work. Take these measurements and information with you when you’re shopping for your new range hood or microwave oven to make sure that the new equipment fits.
If your current ductwork doesn’t fit your new appliances, you’ll have to move the ductwork around. Moving ductwork can be tricky and sometimes seems impossible.
The good news is that in most cases, existing ductwork will work with the new exhaust hood or microwave oven.
Adding ductwork: If your old kitchen didn’t have any mechanical exhaust equipment, your new one will (or at least it should!). Installing new ductwork adds a sizeable chunk of time and labor (and money!) to the remodeling project because all exhaust ductwork must move the air to the outside of the house.
The ductwork runs up and between the ceiling joists and then exits out through the side of the house. The direction the joists run in relation to the location of the stove determines how much work will be involved. If the joists run perpendicular to the exterior wall where the ductwork will exit, you’re in luck because the ductwork can be placed between two of the ceiling joists.
If the stove is on the exterior wall, you should be able to run the ductwork up through the cabinet and out the exterior wall. If, however, the joists run parallel to the exterior wall, you won’t be able to run the ductwork straight out. And you can’t cut holes in the joists for the ductwork, either. The ductwork is either 5 or 6 inches in diameter and even though most ceiling joists are 2 x 10s, cutting a 5 or 6 inch diameter hole in either of these size joists destroys the joist’s structural integrity. If you’re faced with this situation, consult with your building inspector or an architect to explore your options. If major changes are needed, you’ll probably want a contractor to handle that part of the project.