When deciding which range hood is best for your kitchen or if you even need one, it is important to review your state’s residential building codes. These codes outline specific criteria that must be met by your range hood depending on the state you reside in.
Continue reading to familiarize yourself with the IRC guidelines pertaining to range hoods in the state of North Carolina.
Range hoods are required by code in North Carolina if you install an open-top broiler unit. Ranges with integral exhaust systems do not need a range hood. If you install a range hood, you have to follow the design, installation, ducting, and venting guidelines in the code.
IRC: Range Hoods Controlled but Not Required
While the IRC specifies certain criteria that must be met by range hoods, it only explicitly states that range hoods are required in the kitchen if you have a domestic open-top broiler (Section M1503.2.1).
Whether you have to or not, if you do have a range hood, then Section M1503 of the IRC dictates aspects of installation, venting, etc.
For example, it states that range hoods are required to expel discharge outdoors by the use of a duct. Ducts are required to be made of copper, stainless steel, or galvanized steel. The interior of the duct must have a smooth texture, be airtight, have a backdraft damper, and function independently from any other exhaust system in the home.
Here are 5 reasons why it’s important to have a range hood, even though it’s not required by code.
Section M1505.4.4 of the IRC also outlines specific local exhaust rates required to be met by the range hood, but these align with the local codes, so we will discuss them in the sections regarding local codes.
NC Codes Require Metal Exhaust Hoods
Section M1505.1 of the North Carolina Residential Code requires that open-top ranges must have hoods and that these hoods must be made of metal.
This section also specifies that broiler units labeled for use without a range hood and that also possess an integral exhaust system are not required to have an exhaust hood.
An integral exhaust system refers to a specific type of exhaust system that is directly built into the broiler unit.
Because these appliances are equipped with their own integral exhaust system, they do not need an additional exhaust system in place to operate safely. This is the only exception to the rules pertaining to exhaust systems in the kitchen according to the code.
| Minimum Thickness of Metal | 0.0157 inches |
| Minimum Clearance Between Hood and Underside of Cabinets | ¼ inch |
| Minimum Clearance Between Hood and Cooking Surface | 24 inches |
| Width of Range Hood | Cannot be less than the width of the broiler unit and must extend over the entire broiler unit |
For information on insulating the ducting, you can visit Should Range Hood Duct Be Insulated.
Kitchen Range Hood Minimum Exhaust Rate
In North Carolina, your kitchen range hood is required to meet a minimum exhaust rate in order to abide by the code regulations stated in Section M1507.4. For one and two-family dwellings, the minimum exhaust rate for a kitchen range hood is 100 CFM intermittent or 25 CFM continuous.
“CFM” is terminology that refers to how many cubic feet of air an exhaust fan can move per minute. An intermittent exhaust system only operates when it is turned on, and a continuous exhaust system operates throughout the day without having to be turned on or off.
Related article: Reasons Why A Range Hood Is Not Effective
Make-up Air Requirements for Range Hoods
North Carolina provides make-up air requirements pertaining to range hoods in the kitchen that are listed. These are found in Section M1503.4. Make-up air refers to air that is utilized to replace the air that has been removed by the range hood.
Any range hood capable of producing more than 400 CFM is required to have make-up air supplied to the area at a rate equal to that of the exhaust fan. Make-up air systems are required to be enclosed and need to be controlled automatically to operate at the same time as the exhaust system.
If all of the appliances in your home are unvented, electric, direct vent, or power-vent, a make-up air system is only required if your exhaust fan pushes more than 600 cubic feet of air per minute.
Related article: Is a Range Hood Required by Code In California
Sources
https://www.aldes-na.com/residential-ventilation/homebuilders/builder-faq/
https://www.cambridgeair.com/make-up-
air#:~:text=Make%2Dup%20air%20is%20designed,air%20that%20cannot%20be%20recirculated.