How many CFM does a kitchen exhaust fan need?
A local kitchen exhaust must move at least 100 cfm intermittently or 25 cfm continuously, vented outdoors (IRC Table M1507.3).
Where a local kitchen exhaust system is installed, the IRC sets a minimum airflow of 100 cfm for intermittent operation or 25 cfm for continuous operation, per Table M1507.3.
The exhaust must discharge directly to the outdoors — not into an attic, crawl space, or other interior space. (In the 2018 and later IRC these kitchen rates moved to Section M1505.)
Related answers
- How many CFM does a bathroom exhaust fan need? — IRC §M1507.4
- Does a bathroom need a window, or is an exhaust fan enough? — IRC §R303.3
- Where can a clothes dryer vent terminate and does it need a damper? — IRC §M1502.3
- What is the maximum length of a clothes dryer exhaust duct? — IRC §M1502.4.4
- Can HVAC return air be pulled from a bathroom, kitchen, or garage? — IRC §M1602.2
- How much window area do I need for natural light and ventilation in a room? — IRC §R303.1
- How much insulation do HVAC ducts in the attic need? — IRC §N1103.2.1
- How much combustion air does a gas furnace or water heater need indoors? — IRC §G2407.5
Need this scoped to your jurisdiction?
Adopted edition and local amendments vary by city and county. Ask Donnie checks your jurisdiction and cites the exact adopted section.
Ask Donnie →General information based on the International Residential Code (a model code). This is AI assistance to verify — not legal advice. Confirm the adopted edition and any local amendments with your local building department (AHJ) and a licensed professional before you build.