Although designing a kitchen is an exciting process, it’s also one that needs to be taken seriously. In addition to considering various fun and fancy appliances, you need to first think about specific appliance installations, such as a kitchen hood, as these need to align with local rules and regulations for safety reasons.
Commercial range hoods should have an interior lower edge that extends no less than 6 inches above the cooking surface. The vertical height should be no greater than 4 feet. For non-commercial kitchens, hood regulations vary by state. Check your state laws for the specific rules to follow.
Within this article, we have outlined hood requirements in every state with references to official government websites. We have also gone into detail on the importance of kitchen hoods, and how the regulations work.
How Kitchen Hood Requirements Vary By State
Kitchen hood requirements vary by state, meaning they need to abide by certain regulations depending on where your kitchen is located.
While the International Mechanical Code serves as the foundation for most states’ and municipalities’ laws, local rules may have different requirements for specific specifications. That being said, many states have additional restrictions which supersede the IMC.
Check with the local authority before making any decisions on how to set up your exhaust system. We’ve covered some of the basic codes by state below.
Kitchen Hood Requirements by State Chart
|Kitchen Hood Requirements
|Like most states, kitchen hoods in Alabama must exhaust to the outdoors. Find the full specifications here before installing a kitchen hood in Alabama.
|Alaska does require a kitchen hood, but the exact specifications generally follow the IMC. Find the full code here.
|Arizona has its own kitchen hood requirements, and they vary from other states in the distance that must be between the hood and the countertop. Find the full code here.
|Arkansas mostly follows the IMC, but before any project involving the kitchen hood it’s a good idea to review the state specific code.
|In California, you must install a hood which produces 5 air exchanges per hour or 100cfm. This is required for all residential homes. You can find the full details in the California Residential Code.
|Colorado has its own kitchen hood codes. These codes differ in the amount of clearance between the hood and combustible materials as well as in in the thickness of the hood. Review the Colorado code here.
|Connecticut mostly follows the kitchen hood codes applied by the IMC. But you can double check the regulations before you build here.
|Delaware follows the IMC for residential homes, but if you are building a commercial kitchen, it’s a good idea to check out the Delaware codes for commercial kitchens.
|District of Columbia
|The District of Columbia, even though it isn’t technically a state, has its own kitchen hood requirements due to the dense population. Find the codes here.
|Florida, likely due to the humidity, has a minimum requirement of 100 cfm for any kitchen hood to keep the air circulating. Find the full code here.
|Georgia mostly follows the IMC when it comes to kitchen hood installation. But if you live in a large city like Atlanta, it is always a good idea to check local codes before beginning any project.
|For residential homes, Hawaii follows the IMC. If you are building a commercial kitchen in Hawaii, make sure you check the commercial kitchen hood regulations before you begin.
|Idaho has specific size regulations when it comes to installing a kitchen hood. You can find those requirements here.
|Illinois mostly follows the IMC when it comes to kitchen hoods. But if you live in a large city like Chicago, it is a good idea to check city regulations before choosing or installing a kitchen range.
|For residential homes, Indiana follows the IMC. If you are building a commercial kitchen, double check the regulations here.
|Iowa follows the IMC for kitchen hood requirements.
|Kansas mostly follows the IMC for kitchen hood regulations, but before beginning any construction project, it is a good idea to double check the regulations yourself here.
|Kentucky has some expanded requirements when it comes to the thickness and materials used to build a kitchen hood. You can find the full details in the Kentucky Residential Codes.
|Louisiana follows the IMC for all kitchen hood requirements.
|Maine, like many other states, mostly follows the IMC for residential homes. If you are planning to open a restaurant, however, it’s a good idea to look into the commercial codes before you begin.
|Maryland has specific requirements for where the duct from a kitchen hood exhausts. You can find the full requirements here.
|Massachusetts has its own specific requirements for kitchen hoods. You’ll need to review them here before beginning any project involving the kitchen hood.
|Michigan follows the IMC for all kitchen hood codes.
|Minnesota mostly follows the IMC for kitchen hood codes, though they do have a few requirements of their own which you can find in the Minnesota Residential Code.
|Mississippi follows the IMC for most kitchen hoods, but commercial hoods may have different requirements which can be reviewed here.
|Missouri mostly follows the IMC for kitchen hood codes, but there might be some slight differences which can be found here.
|Montana has specific requirements where a kitchen hood duct can vent. You can find the full specifications here.
|Nebraska mostly follows the IMC, but there are a few minor changes in the types of hoods that can be used which you can find here.
|Nevada mostly follows the IMC as well, but there are some small changes in the types of ducts which can be used for kitchen hood exhaust. Find the regulations here.
|New Hampshire follows the IMC for most kitchen hood situations. You should still check the codes prior to any project which can be found here.
|New Jersey, since it has a lot of large metropolitan areas, has its own kitchen hood codes which must be adhered to in any building project. Find them here.
|New Mexico has its own venting requirements for all kitchen and bathroom fans. You can find the code here.
|New York State
|New York State is very large with many metropolitan areas. There are very specific requirements when it comes to when a kitchen hood is required and where it needs to vent. Check the New York Kitchen Hood Requirements before beginning a project.
|North Carolina mostly follows the IMC when it comes to kitchen hoods.
|North Dakota follows the IMC for kitchen hood requirements.
|Hoods must be erected in Ohio with a minimum distance of 1/4 inch (6.4 mm) between the hood and the underside of flammable material and cabinets. Find the full code details here.
|Oklahoma, like many other states on this list, follows the IMC for kitchen hoods.
|Oregon, although it mostly follows the IMC, does have its own code for kitchen hoods which can be found here.
|Pennsylvania follows the IMC for kitchen hood codes.
|Rhode Island follows the IMC for kitchen hood codes.
|South Carolina follows the IMC for kitchen hood codes.
|While South Dakota mostly follows the IMC, there are specific requirements for commercial kitchens which can be found here.
|Tennessee follows the IMC for kitchen hood codes.
|In Texas, all kitchen hoods must be equipped with grease filters. There are also some additional requirements which are specific to the state. If you live in a large metropolitan area like Dallas or Houston, you should check the city codes for additional regulations as well.
|Utah has specific requirements for materials used to build kitchen hood ducts. Find the full requirements here.
|Vermont mostly follows the IMC unless you are outfitting a commercial kitchen with a hood. Then you will need to double check the requirements in the state fire code.
|Virginia follows the IMC for kitchen hood requirements.
|According to municipal requirements in Washington, domestic kitchen appliances used for commercial purposes must be equipped with Type I, Type II, or residential hoods depending on the type of appliances and operations. These require an overhang of 6 inches or less. Review the Washington Code before starting any kitchen renovation project.
|West Virginia follows the IMC for kitchen hood requirements.
|Wisconsin has its own code for kitchen hood requirements which can be reviewed here.
|Wyoming mostly follows the IMC, however anyone looking to install a hood in a commercial kitchen will need to double check these regulations before installation.
Installing The Kitchen Hood
It may be taken for granted by those who don’t manage a restaurant kitchen that kitchen safety encompasses much more than just food safety. In fact, creating a well-liked menu may end up being the easiest aspect of running a restaurant because there are so many rules and considerations to make.
Fortunately, you really only need to be concerned about restaurant hood laws when setting up your kitchen. Once you fully comprehend everything, you won’t be intimidated when it comes time to renovate your kitchen and make changes to improve hood efficiency or add new types of hoods.
However, it is always advisable to speak with a commercial HVAC expert who is knowledgeable about restaurant vent hood specifications down to the slightest nuance. This can put your mind at ease regarding correctly installing a stove hood.
After all, Type I commercial hoods are crucial for preventing fires and ensuring the well-being of everyone in your restaurant, so do not attempt them half-heartedly.
Seeking expert help will guarantee your kitchen hood aligns with the laws and regulations to avoid fines and issues. Plus, the safety of installation will be guaranteed, ensuring keeping yourself and others safe when in the kitchen workspace.
Why Do Kitchens Need a Hood?
All kitchens must align with set regulations when it comes to equipment, especially cooker hoods.
Kitchen or range hoods are used to ventilate the kitchen by soaking up poor-quality air to improve the air quality in the space. Plus, they work to remove any dangerous particles in the kitchen, making it a safer place to cook and eat.
A kitchen needs a hood to maximize cleanliness and safety. Without a hood, grime, grease, and bacteria will remain in the kitchen until thoroughly cleaned.
Using a hood does most of the dirty work for you and also ensures your kitchen adheres to regulations.
What Factors Go Into Kitchen Range Hood Regulations?
Various factors are considered for each range hood regulation, which are as follows:
Size of the Hood
The size of the hood is a key factor when it comes to regulations as the vertical distance and the overhang should not exceed certain measurements.
In most cases, commercial vent hoods should have an interior lower edge that hangs over or extends no less than 6 inches above the rim of the cooking surface or appliance it is mounted above.
The vertical height above the cooking surface should not be greater than 4 feet.
Commercial vs. Non-Commercial
A hood is typically necessary for commercial kitchens to provide a secure working environment and to adhere to local laws.
There are, however, several circumstances in which a kitchen may have to function without one. Some kitchen appliances might be exempt from your local health code, enabling them to run without a kitchen range hood, depending on their size, power usage, and heat production.
Before deciding to buy or use any equipment without a hood, it’s important for your safety to consult with the relevant authorities in your area.
Some of the most popular exempt appliances are listed below:
- Dishwashers that fit under counters
- Lightweight microwaves
- A popcorn maker
- Hot dog grills
- Espresso machines
- Risotto pots
- Holding cupboards
- A few counter steamers
There are no set regulations for non-commercial kitchens. No national construction code mandates the installation of a ventilation system in the kitchen, but if you choose to do so, national standards and codes do apply.
As always, the codes are in place for your health and safety.
Mechanical ventilation, such as an exhaust fan, is mandated by several state building rules in the kitchen.
However, you must abide by the regulations if you run a commercial kitchen.
Type of Cooking
Kitchen hoods should be used for all types of cooking in commercial settings. They can be used similarly in non-commercial kitchens.
It’s best to use hoods when steaming or fry is happening as the hood will ventilate the steam and grease. The ventilation system inside the hood will keep the air clean and bacteria-free.
Type I vs. Type II Hoods
There are two types of kitchen hoods: Type I and Type II. Type I is most common for removing heat and smoke. Meanwhile, Type II is best for steam and other vapors.
Below is an understanding of each type of hood and what its benefits are:
Type I Hoods
Grease hoods, often referred to as Type I hoods, are intended to remove heat, smoke, and grease that is in the air.
These hoods are frequently seen above kitchen appliances such as ovens, broilers, grills, and fryers.
There are specific requirements Type I hoods need to meet:
- Keep joints sealed: Welding or brazing is not necessary for internal joints. All joints should remain sealed. Joints, seams, and penetrations should all be protected by continuous exterior liquid-tight welds or brazes that extend to the hood’s lowest outermost perimeter.
- Labeling: The minimum exhaust flow rate in cubic feet per minute (CFM) per linear foot shall be marked on each hood.
- Create the proper support: Ensure that noncombustible supports are used to hold each hood in place.
- Keep combustibles away: Install your hood at least 18 inches away from anything that could catch fire.
Type II Hoods
Type II hoods, also known as condensate hoods, function to remove moisture from the air, including steam and vapor. In some Type II hoods, odors are even removed.
They are frequently discovered on top of commercial dishwashers, some pizza ovens, and coffee makers. Additionally, these hoods frequently don’t have grease filters, so they shouldn’t be compared to Type I hoods.
There are specific requirements Type II hoods need to meet:
- Build strong supports for the hood: These supports should be able to withstand the weight of the hood, unsupported ducting, effluent load, and perhaps even the weight of any workers.
- Internally seal joints: Type II hoods should have interior joints, seams, and penetrations that are sealed. The interior should have a smooth, water-tight surface that is simple to clean.
What Are the Legal Requirements for a Commercial Kitchen Hood?
For commercial kitchens, there are legal requirements that kitchen hoods need to meet.
Below, you can find everything you need to know about the specific requirements for commercial kitchen hoods.
Must Meet the Minimum Overhang Requirement
There is a minimum overhang requirement for commercial kitchens.
Commercial hoods should have a minimum 6-inch overhang or extension from the edge of the surface or appliance they are mounted above.
Must Be Within The Specific Elevation Range
There is also a limited elevation range a kitchen hood needs to meet. There should be no more than four feet between the kitchen oven and the hood for safety reasons.
The smaller the gap, the more efficient the ventilation will be.
Must Use Proper Equipment
For legal, health, and safety reasons, it’s essential for kitchens to be equipped with the proper equipment when using kitchen hoods.
First, the kitchen must have the correct fire equipment. Under a Type I hood, every commercial appliance must be equipped with an authorized automatic fire suppression system. The International Building Code and International Fire Code should be followed by this system.
Furthermore, it must utilize the appropriate tools. Heavy, medium, and light-duty equipment should not be placed above hoods designed for usage above extra-heavy-duty machinery. Doing so could cause incidents.
What Are the Requirements for a Non-Commercial Kitchen Hood?
Although there are no specific legal regulations for non-commercial kitchen hoods, there are codes to abide by.
These codes depend on the state you live in. For example, if you live in California, your local authorities might not mandate codes. However, you should nonetheless handle kitchen ventilation even if they do not.
California requires it in all new buildings and remodels. By installing a range hood, you may generally meet municipal regulations. Range hoods have a cubic foot per minute (cfm) capacity rating.
To determine the necessary capacity, multiply the total heat output of the range in British thermal units (Btu) by 100 (for intermittent systems) or 400 (for continuous systems).
For instance, a normal 40,000 Btu gas burner stove requires a range hood with a 400 cfm capacity if the hood can be turned on and off. If it’s always on, it simply has to be capable of moving 100 cfm, which is only 25% as much as a system with an on/off switch.
Energy Efficiency Matters
The hood also needs to be energy efficient, as the DOE states. It outlines two standards that all kitchens must meet.
To prevent wasting the energy used to heat and cool this air, they must only use a small quantity of makeup air, which is air taken from other parts of the house.
The second requirement is that they cannot be “short-circuit” hoods, or those that pull air for makeup from the outside. They should only use makeup air that is drawn from within the structure, with no outside air being permitted.
The Design Regulations
Instead of venting into the attic or crawl space, the duct should exhaust air to the outside of the structure through the roof or a wall on the exterior. The outlet must be covered with a grille, screen, or louver and be at least 10 feet away from any windows or other air inlets.
A backdraft damper is required on the exhaust duct to stop outside air from entering the exhaust system. The damper can be integrated into the vent cover or positioned slightly outside the hood itself.
Galvanized steel, copper, or stainless steel should be used to construct the smooth and straight ductwork for the exhaust system. The ducts must be mechanically secured and taped or mastic-sealed.
If some tape is used, it should have a metal backing rather than a textile backing like regular duct tape, which might crumble and dry out.
Overhang Requirements: What to Know
The overhang of your kitchen hood will depend on testing of the specific model and manufacturer. Most should test and abide by an overhang of fewer than 6 inches or 152 mm.
If your kitchen hood passes the test, the end overhang will be listed in the regulation listing and must be at least 6″ (152mm) long when installed. If the application calls for more than the minimum for proper capture and containment, you can have that.