Get Residential Kitchen Range Hood Certification Program ...

Although the international CFM code for range hoods is 100CFM, some local authorities allow for range hoods with slightly lower or higher CFM than this, depending on the type of your cooking, and the square footage of your cooktop.

Type II hoods shall be constructed of steel having a minimum thickness of 0.0296 inch (0.7534 mm) (No. 22 gage) or stainless steel not less than 0.0220 inch (0.5550 mm) (No. 24 gage) in thickness, copper sheets weighing not less than 24 ounces per square foot (7.3 kg/m2) or of other approved material and gage.

Range hoods do not have to be vented to the outside. You can purchase hoods without ductwork called ductless hoods. But, ducted range hoods are almost always preferred over ductless hoods.

NFPA 96 is the industry standard for the cleanliness and maintenance of commercial kitchen exhaust systems. As you use cooking equipment, vaporized grease solidifies inside the ventilation ducts over time, creating an inevitable fire hazard.

To meet the recommended CFM requirements, you'll need a range hood with 250 CFM. Island hoods – 150 CFM for every linear foot of cooktop. Due to the open nature of a kitchen island stove, you need extra power. As a general rule of thumb, for the same 30” cooktop, you'll need a range hood with 375 CFM.

Although the international CFM code for range hoods is 100CFM, some local authorities allow for range hoods with slightly lower or higher CFM than this, depending on the type of your cooking, and the square footage of your cooktop.

A good rule of thumb for estimating duct diameter and CFM requirements is: 6” to 8” duct = 400 to 600 CFM. 7” to 10” duct = 700 to 900 CFM. 8” to 12” duct = 900 to 1200 CFM 10” and up duct = 1200 and higher CFM.

To power your range hood, you need at least 100 CFM for every 10,000 BTUs of your stovetop. For example, a 100,000 BTU stove needs at least a 1000 CFM range hood. For electric stoves, multiply the stove width by 10. So, for a 42” electric stove you want a range hood with at least 420 CFM.