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Type 1 vs type 2 hood questions

J

jokergerm

New member
Well I was told something today that contradicts my years of building pizza stores and hanging hoods

Normally a type 2 hood just takes out heat and has no fire sup. system But has a cold air return

and type 1 has fire sup and cold air return and totally welded ducting and hood.
Well I was talking to my restaurant supply lady and she said that type 2 was only heat removal, no fire and no return air

and that type 1 was heat removal and cold air return and fire sup, is only required for open flames such as deep fryers or stoves with open flame

So if she is correct both my stores have a type 1 with out fire sup. Since they take out heat and have a cold air return

I am assuming that she is confused but I know for a fact someone on here knows what it really is

Im still under the impression that I am correct
 
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My store and every store I’ve seen is exactly what your supply lady said
 
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Same as the supply lady in NY. My building inspector made me put type I hoods over both my oven and fryers. NYS code anything that produces grease vapors he said.
 
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type one is about removing heat, fumes and aerosolized grease from exhausted air. Because of the grease, fire suppression is essential. When cooking anything that produces grease fumes, Type 1 is a must. It will have baffles for grease capture as well. I have heard from owners that some local jurisdictions do not require type 1 for pizza oven alone … not many and not verified.
 
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Gentlemen

We sell hoods all over the nation and every place we do they require pizza ovens to use a class one hood, with fire suppression. All exhausted air must be returned, About 1/2 the returned air can be brought directly into a compensating hood. The rest of the return air is best brought in through The air conditioning system which can heat or cool that incoming air. If there is not sufficient A/C to handle the volume of return air a make up air unit can be used but it must be capable of heating cold air to within 10 degrees of normal room temperature usually 60 degrees. Its best to equip the make up air unit to also cool the hot summer air or else you will find your kitchen very hot to work in.

The rules concerning hoods are enforced by the building department. BOCA code The fire marshal enforces the fire suppression rules. NFPA rules. the health department enforces the sanitary rules NSF

These are national codes, local jurisdictions can impose stricter rules.

George Mills
 
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Thanks George

Guess I’ve just been lucky. I have built and opened 6 pizza stores in Washington state in the last 8 years and never have been required type 1

However I am moving a store in the same town to a new building and they are requiring it I think

Not looking forward to dumping 10k into a hood system when I already have 3 type 2 hoods in my garage
 
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I’ve opened three stores. All with type 2. Without any cold air return, I may add. All were inspected up one side and down the other. Cold air return would be silly in this local, as the more captured heat the better. I will admit this was over 10 years ago, so things may have changed. My advise is to ASK before you install.
 
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Hi smeasol8

The reason for returning an amount of air into the building is not about the temperature in or outside the building. It is to prevent negative air pressures in the building.

The problems caused by negative building pressurization range from issues of comfort - cold drafts and noxious odors that rush in through cracks and door openings - to serious safety concerns. Outside doors may be difficult to adjust and open, and dangerous to close. Flues that were intended to discharge combustion byproducts from furnaces, heaters and other equipment inside the building may back-draft. Instead of the odors and materials being discharged through the flues out of the building, they can be brought back in and circulated. “This can create quite a serious carbon monoxide and safety issue,”In the summer months, negatively pressurized buildings can produce condensation on diffusers and other equipment used to cool the building, creating wet building materials and the potential for mold growth.

George Mills
 
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Hi smeasol8

The reason for returning an amount of air into the building is not about the temperature in or outside the building. It is to prevent negative air pressures in the building.

The problems caused by negative building pressurization range from issues of comfort - cold drafts and noxious odors that rush in through cracks and door openings - to serious safety concerns. Outside doors may be difficult to adjust and open, and dangerous to close. Flues that were intended to discharge combustion byproducts from furnaces, heaters and other equipment inside the building may back-draft. Instead of the odors and materials being discharged through the flues out of the building, they can be brought back in and circulated. “This can create quite a serious carbon monoxide and safety issue,”In the summer months, negatively pressurized buildings can produce condensation on diffusers and other equipment used to cool the building, creating wet building materials and the potential for mold growth.

George Mills
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Sewer gas incursion bubbling up through your P-Traps is always fun when you have negative pressure situations, I battled that for my first few weeks because the previous owner of this building had a used short-cycle hood installed by amateurs. The make-up air fan was wired backwards, so it was also sucking air out instead of replacing air. And there was a single 6" duct, I installed two 12" MUA ducts to make it correct. Screwed with pulley widths for hours, and it is better but still sucks. And buying a new tempered MUA hood is not what I want to do right now

Since I do not feel like replacing a 14’ hood with the a tempered make-up air hood, so I am making some interesting modifications using newer technology. If it works as expected, I’ll share the parts list and how to do it with this page.

I am adding a variable speed exhaust fan, it’ll be 3-phase motor running off 110VAC with a phase converter instead of running 3-phase to the roof. I will use pressure sensors in the hood coupled with motorized dampers in my make-up air ducts. This way I can set my exhaust fan speed via rheostat to meet my current needs for the conditions, the pressure sensors will activate the dampers on the MUA ducts and that should give me near perfect pressure equalization no matter the speed of my fan.
In the mornings, I do not need much exhaust, I basically just have sweet tea brewing, no fryers on, the broiler is off. But when we get in full swing and I have every piece of equipment on the line fired up, I need more evacuation

I also plan to do a smaller closed loop geothermal system in the near future, I’ll share that too. it’ll be used for heating and cooling depending on the season.
 
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jokergerm said:
Thanks George

Guess I’ve just been lucky. I have built and opened 6 pizza stores in Washington state in the last 8 years and never have been required type 1

However I am moving a store in the same town to a new building and they are requiring it I think

Not looking forward to dumping 10k into a hood system when I already have 3 type 2 hoods in my garage
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In San Francisco, we’re only required to have Type 2 for a conveyor oven/deck oven. I was very happy and surprised when I received the news. San Francisco is the pickiest place on earth to open a business, especially a restaurant so I thought they’d be sticklers on the hood type for conveyors. What size hood are you putting above your conveyors? 8 ft or 10 ft?

Congrats on your success thus far, will hope to catch up to your count soon!
 
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Hi Gotrocks;

Check with your building department 3 speed fans are not generally approved for food service hoods.

George Mills
 
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Hi Joe:

In San Francisco, we’re only required to have Type 2 for a conveyor oven/deck oven.
I am surprised it is the national code to use type one.
Get the building department to put it in writing before you proceed. We have had several instances where our clients were told something by someone and later found that it was not so and had to redo the job.
George Mills
 
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Hi Gotrocks;

Check with your building department 3 speed fans are not generally approved for food service hoods.

George Mills
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Thanks for the info, do you know the reasoning behind that?? I see it as a way to save energy
I plan to use a full variable speed system that is adjustable from idle to full speed and have my MUA compensate automatically to keep as near neutral inside as I can due to solid-fueled naturally drafted equipment being used here.

We are all supposed to have tempered MUA systems due to recent legislation at the state level, (A major hood manufacturer that’ll remain nameless lobbied for it to boost their sales) but the local zoning guy is letting that slide until he is forced to enforce it. I am in a very rural area, so enforcement is not as tight as large cities are.
 
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Hi Gotrocks;

Check with your building department 3 speed fans are not generally approved for food service hoods.

George Mills

“Thanks for the info, do you know the reasoning behind that?”
Hoods are tested and approved to operate at a specific rate of exhausted air. Any decrease defiantly, an perhaps an increase causes the system to be out of balance and not properly remove the contaminants.
A system like you propose would have to be submitted to one of the approved testing laboratories and pass their certification process. A rather costly undertaking.
George Mills
 
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Sorry to hijack this thread, but I’m hoping George can clear up something I’ve always wanted to know - hood requirements for solid fuel appliances. For instance, if I have a wood burning char-grill next to a fryer or pizza oven, am I to understand that there must be a separate hood for the grill AND spark arrestors? Or is it enough to just have spark arrestors above the solid fuel portion? Thanks in advance.

Patrick
 
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Hoods are tested and approved to operate at a specific rate of exhausted air. Any decrease defiantly, an perhaps an increase causes the system to be out of balance and not properly remove the contaminants.

George Mills
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That is exactly where my pressure sensors and variable dampening MUA ducts will come into play, to meet an equilibrium so I do not have negative or positive pressure or any cooking vapors leaving the envelope of the exhaust hood.
There is already Tempered MUA hoods out there that do this, I am just borrowing newer technology and adding it to a short-cycle hood as opposed to replacing an entire hood system.
 
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Hi gotrocks

There is already Tempered MUA hoods out there that do this, I am just borrowing newer technology and adding it to a short-cycle hood as opposed to replacing an entire hood system.

If your inspetor approves you may be ok but I would discuss your plan with them before you get to far.

Let us know the outcome.

George mills
 
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