710B Hood Requirements

[OMSS]

Hello all,

I purchased a used 710B hood so that I could purchase a fryer for my restaurant. It is specifically an American Hood Systems AVH 23:

https://www.americanhood.com/products/ventless_hoods/ventless_hood.html

I planned on getting it professionally installed with all of the permits. The fire marshal is not having an issue with it, but the building inspector is saying that I need a Type 1 hood for a fryer, and it needs to vent out of the building.

I also know that I will only be able to use UL197 electrical fryers with it as well.

I thought the whole point of these types of hoods were that they are used when you can't vent out of the building?

Is there something that I am missing? Any help would be appreciated.

 

[Yikes]

Where is your project located? More specifically, what is the applicable code for that area?

 

[OMSS]

Where is your project located? More specifically, what is the applicable code for that area?

I'm in NC. My city follows the North Carolina State Building Code.

 

[Yikes]

I'm in NC. My city follows the North Carolina State Building Code.

Thanks, I didn't want to assume your project was in-state. North Carolina adopted the 2018 North Carolina Mechanical Code, based on the 2015 IMC.

See NCMC 507.1 exception #2 below.
https://up.codes/viewer/north_carolina/imc-2015/chapter/5/exhaust-systems#507.1

507.1 General​

Commercial kitchen exhaust hoods shall comply with the requirements of this section. Hoods shall be Type I or II and shall be designed to capture and confine cooking vapors and residues. A Type I or Type II hood shall be installed at or above all commercial cooking appliances in accordance with Sections 507.2 and 507.3. Where any cooking appliance under a single hood requires a Type I hood, a Type I hood shall be installed. Where a Type II hood is required, a Type I or Type II hood shall be installed. Where a Type I hood is installed, the installation of the entire system, including the hood, ducts, exhaust equipment and makeup air system shall comply with the requirements of Sections 506, 507, 508 and 509.

Exceptions:

1. Factory-built commercial exhaust hoods that are listed and labeled in accordance with UL 710, and installed in accordance with Section 304.1, shall not be required to comply with Sections 507.1.5, 507.2.3, 507.2.5, 507.2.8, 507.3.1, 507.3.3, 507.4 and 507.5.
2. Factory-built commercial cooking recirculating systems that are listed and labeled in accordance with UL 710B, and installed in accordance with Section 304.1, shall not be required to comply with Sections 507.1.5, 507.2.3, 507.2.5, 507.2.8, 507.3.1, 507.3.3, 507.4 and 507.5. Spaces in which such systems are located shall be considered to be kitchens and shall be ventilated in accordance with Table 403.3.1.1. For the purpose of determining the floor area required to be ventilated, each individual appliance shall be considered as occupying not less than 100 square feet (9.3 m2).
3. Where cooking appliances are equipped with integral down-draft exhaust systems and such appliances and exhaust systems are listed and labeled for the application in accordance with NFPA 96, a hood shall not be required at or above them.

304.1 General​

Equipment and appliances shall be installed as required by the terms of their approval, in accordance with the conditions of the listing, the manufacturer's installation instructions and this code. Manufacturer's installation instructions shall be available on the job site at the time of inspection.

 

[OMSS]

This part is what confuses me:

"Spaces in which such systems are located shall be considered to be kitchens and shall be ventilated in accordance with Table 403.3.1.1. For the purpose of determining the floor area required to be ventilated, each individual appliance shall be considered as occupying not less than 100 square feet (9.3 m2)."

Does this mean that I will still need a vent in my kitchen? Is there anyway to achieve the required ventilation without installing a hood?

 

[Yankee Chronicler]

Hoods are not "ventilation." Hoods are source capture exhaust.

I'm not in North Carolina but I'm pretty certain you can't have a fryer without a grease hood. That's Type 1.

Commercial Kitchen Hood Type 1 vs Type 2: Key Differences and How to C

Commercial kitchen hoods are an essential component of any restaurant or food service establishment. They are designed to remove smoke, heat, and grease from the air, ensuring a safe and comfortable working environment for kitchen staff. There are two main types of commercial kitchen hoods: Type...

therestaurantauthority.com

 

[Sifu]

A 710b hood is a listed recirculating hood, but still a capture and containment system. Many of the requirements for a type I hood are excepted when you use a 710b hood. The statement about the ventilation simply refers back to the outdoor air and exhaust requirements for commercial kitchens, and explains that whatever appliance (fryer) you have under the 710b hood adds 100sf² to the area of the kitchen. So since you now have a kitchen, if your kitchen is physically 500sf² and you have a single fryer you have to provide outdoor air and environmental exhaust based on 600sf².

However, I'm not sure you can mix and match random appliances and random 710b hoods together. You must install it according to the manufacturer specifications so you need to check and see if your appliance is specified by the hood manufacturer. I think the 710b listing is for a complete package, but not 100% sure. I have only ever seen them as packaged systems, such as a McDonalds fryer.

Now I'm hungry.

 

[klarenbeek]

Hoods listed to 710B are type I hoods. Some are listed to go with specific appliances like the McDonalds' example, others are more generic and can be used over most appliances as long as they are electric. Check the listing for the specific hood you have. The ventilation rate in table 403 is a general exhaust rate that is usually more than covered if hoods exhaust to the outside. Its just simple space exhaust, plus occupancy fresh air that's normally taken care of with the makeup air system

 

[OMSS]

A 710b hood is a listed recirculating hood, but still a capture and containment system. Many of the requirements for a type I hood are excepted when you use a 710b hood. The statement about the ventilation simply refers back to the outdoor air and exhaust requirements for commercial kitchens, and explains that whatever appliance (fryer) you have under the 710b hood adds 100sf² to the area of the kitchen. So since you now have a kitchen, if your kitchen is physically 500sf² and you have a single fryer you have to provide outdoor air and environmental exhaust based on 600sf².

However, I'm not sure you can mix and match random appliances and random 710b hoods together. You must install it according to the manufacturer specifications so you need to check and see if your appliance is specified by the hood manufacturer. I think the 710b listing is for a complete package, but not 100% sure. I have only ever seen them as packaged systems, such as a McDonalds fryer.

Now I'm hungry.

So the hvac should take care of bringing in outdoor air correct?

I'm gonna pick up a used Giles fryer that typically goes with this unit.

 

[OMSS]

Hoods listed to 710B are type I hoods. Some are listed to go with specific appliances like the McDonalds' example, others are more generic and can be used over most appliances as long as they are electric. Check the listing for the specific hood you have. The ventilation rate in table 403 is a general exhaust rate that is usually more than covered if hoods exhaust to the outside. Its just simple space exhaust, plus occupancy fresh air that's normally taken care of with the makeup air system

Is the hvac system considered a make up air system?

 

[klarenbeek]

It can be, depends on the system design and size. It would have to be interlocked with the exhaust to bring fresh air in when the exhaust is on. If you are going with recirculating hoods and then general exhaust, I pass it if the exhaust/fresh air comes on with the lights come on in the kitchen. that way its on when the kitchen is occupied.

 

[Yankee Chronicler]

It can be, depends on the system design and size. It would have to be interlocked with the exhaust to bring fresh air in when the exhaust is on. If you are going with recirculating hoods and then general exhaust, I pass it if the exhaust/fresh air comes on with the lights come on in the kitchen. that way its on when the kitchen is occupied.

This is basically correct, but a properly designed system will be a bit more complicated. Excluding the hood, an occupied space generally requires mechanical ventilation (we don't rely on windows for ventilation in commercial buildings any more). Mechanical ventilation requires a minimum volume of outdoor fresh air for each occupant, but this is usually a small fraction of the total volume of air circulated for temperature and humidity control. As a ballpark, many systems today operate on a ratio of 20% outdoor air and 80% recirculated air. In other words, however much air is being moved through the system, at any time 20% gets exhausted and replaced with fresh air, and 80% gets recycled.

So that's what a kitchen would require -- without taking the hood into consideration.

Add in a hood, and that changes. NCMC 507.1, Exception #2, refers you to Table 403.3.1.1. And Table 403.3.1.1 has NO outdoor air requirement for a commercial kitchen, but it DOES require exhaust of 0.7 cfm/sf. We also have to look at footnotes a and b.

Footnote a says this is based on the net occupiable floor area -- and then you have to add in 100 s.f. for the recirculating hood.

Footnote b says "Mechanical exhaust required and the recirculation of air from such spaces to other spaces is prohibited. Recirculation of air that is contained completely within such spaces shall not be prohibited (see Section 403.2.1, Item 3)." This means that air used to ventilate the kitchen cannot be mixed with air used to ventilate any other spaces in the building. However much air is being exhausted has to be replaced by new, fresh air supplied by the system to the kitchen.

 

[klarenbeek]

And Table 403.3.1.1 has NO outdoor air requirement for a commercial kitchen, but it DOES require exhaust of 0.7 cfm/sf. We also have to look at footnotes a and b.

I stand corrected on that one. Had to go dig in the archives and open our 2015 IMC. it doesn't have fresh air requirements yet, just exhaust. Fresh Air was added in the 2018 IMC. And yes, I figure only that portion of total airflow that is outside air, not all of the total airflow.

 

[Sifu]

Kitchens do have outdoor air requirements as of the 2018 IMC. I think NC is at least once cycle behind the ICC codes, so if they are on the 2018 NCBC/NCMC it may not apply, but you need to verify the edition and specifically the table to verify whether the NCMC picked up this change.

 

[Yankee Chronicler]

Kitchens do have outdoor air requirements as of the 2018 IMC. I think NC is at least once cycle behind the ICC codes, so if they are on the 2018 NCBC/NCMC it may not apply, but you need to verify the edition and specifically the table to verify whether the NCMC picked up this change.

Yes. I used the North Carolina code, as presented on UpCodes. That's the code in effect for the project.