Keeping your home safe and having clean, quality indoor air is essential for your family’s health. What you cook, how you cook it, and the fumes, smoke, grease, odors, and steam that cooking creates all play a major role in indoor air quality. A kitchen exhaust fan helps to remove these components of cooking to keep your indoor air safe and clean.
Ducted kitchen exhaust fan
As home inspectors, we come across many variations of kitchen exhaust fans, with just as many questions regarding kitchen exhaust. Some vents exhaust to the exterior, some recirculate, and sometimes kitchen exhaust vents are just nonexistent.
Are kitchen exhaust fans required?
There are no requirements in the International Mechanical Code requiring exhaust fans in residential kitchens. There are, however, requirements for the installation of exhaust fans. Section 505 explains these requirements.
Although not required, kitchen exhaust fans are a good idea and should exhaust to the outside (exterior) of your home. Even the best cooks can burn something on the stove or create a meal that has some pretty strong odors!
My wife and I learned from a recent new-home build that proper sizing is important when choosing a kitchen exhaust fan. My wife showed me a model that could run at 900 cfm. We thought that bigger was better, as the kitchen, dining room, and great room were all one big space. When we got the quote back from the HVAC contractor, there was a line item for a $3,600 make-up air system on the bid. We asked about this, and the contractor shared that the code requires make-up air for anything over 400 cfm. Because the exhaust fan we chose was so powerful, the make-up air system had to also be able to heat or condition the make-up air. We returned the unit and found a fan that was below the make-up air requirement.
Ductless or ducted?
Exhaust fans come in two types of systems; they can either be ducted or ductless (recirculating). Most over-the-stove microwaves are equipped with an exhaust fan, and they generally have the option to be installed as either ducted or ductless.
A ducted system vents the exhaust to the exterior of your home. A ducted system should not exhaust kitchen air into the attic space because any moisture in that air can potentially create serious issues. Ductless (recirculating) systems draw the air from immediately above the stove and vent it directly back into the kitchen environment.
Our home inspectors look for vent terminations on the exterior roof or wall when inspecting the exterior of the home. A ductless system has a fan that circulates the air through a filter and returns it to the room. The downside of a ductless system is that if you burn something or have strong odors, they are not removed from the living space.
Summary
Even though exhaust fans are not required, our home inspectors will note on the home inspection report whether or not the exhaust fan in the kitchen is venting to the exterior or not. We will also note if there is no exhaust fan on the home inspection report and explain to our clients the importance of a proper exhaust fan to keep the air inside your home clean and safe.
At HomePro Inspections, our home inspectors are trained to look for and report any potential ventilation issues. Any issues are documented in your home inspection report and recommended for resolution by a qualified professional.
Visit our website to learn more or to schedule your home inspection in the Rochester, Owatonna, and Faribault, MN areas. You can contact us today at (507) 202-8942 or utilize our online “Schedule Now” feature to set up an appointment.