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Nuisance Odors

north star

Sawhorse
Joined
Oct 19, 2009
Messages
4,596
> > > 6

I have a facility that is in the process of [ trying ] to open a small Cafeteria

inside a building, by a new contractor.

There has been some verbal input \ comments made in the past & a few
currently, as to the cooking smells being ventilated throughout the entire
building.........The Cafeteria area in question does not have its own HVAC
system, rather it is connected to the whole building system [ i.e. -
the supply air & the
return air ].

Q1): Is there anything in the Mech. Codes, Fire Codes or other that
addresses containment of; in this case, "cooking odors" [ i.e. - the odors
originating from a particular room \ area \ space should:
(a) be contained
in that space, or
(b) be directed to the exterior of the building ?

NOTE: In the `21 IMC, Sect. 501.3, Exception # 3 seems to not require
"exhausting to the exterior by commercial cooking recirculating systems",
while Section 502.1.3 seems to require that "odors" be exhausted to the
exterior".

Anyone care to try and explain ?

Thank you !


< < < 3
 
Last edited:
I'd suggest verifying that all hoods and mechanical exhaust equipment in the kitchen area are functioning correctly and at the appropriate velocity/flow rates. Could be either an equipment issue or an operations/user issue.

From a code perspective, exhaust ventilation should convey most of the cooking odors to the exterior of the building. That said, air circulated for heating/cooling would be mixed throughout the building if the cafeteria area is not on an independent air handler. Possible solution is to reconfigure the location of the return air grate further away from any source of odor. Be sure to rebalance the system if the return air is relocated. Depending upon the layout and where there may be doors or other impedances to airflow movement, it would be ideal to not have a return air grate in the cafeteria at all (i.e. positive pressure in the cafeteria, draw from office space).

But back to the question, this is not explicitly a code issue. Code will require the ventilation of the cooking vapors via a hood, but if it is simply odors, such as those from a buffet line, it is not a code issue. Remember that the code is the minimum standard and not best practice. Just because it is not a code violation, doesn't mean it is right.
 
# ~ #

The prior and existing set-up is with cooking appliances with
filters to capture the greasy \ oily particulates from the cooking
ops. ( two appliances I believe ).

The odors could be generating from a microwave or other
source, and sending the smells \ odors to throughout the
building........They are picked up through the Return Air
and distributed to other parts of the whole building.
Smells \ odors like: bacon, ...eggs, ...fried chicken parts,
and other for the breakfast & lunch menus.

As much I like to smell bacon, eggs and fried foods, I don't
know that I would want that smell being ventilated to my
space \ area throughout parts of every day.

On another related note, if this issue gets elevated enough
to require the new contractor to install a wholly separate
exhaust system, it would most probably put them out of
business..........Just sayin'...


# ~ #
 
classic T had things to try. The thing is, it's really difficult to stop smells from migrating and you can put in money and effort with little if any success. If it is a deal breaker they should reconsider early on.
 
> > > 6

Q1): Is there anything in the Mech. Codes, Fire Codes or other that
addresses containment of; in this case, "cooking odors" [ i.e. - the odors
originating from a particular room \ area \ space should:
(a) be contained
in that space, or
(b) be directed to the exterior of the building ?

NOTE: In the `21 IMC, Sect. 501.3, Exception # 3 seems to not require
"exhausting to the exterior by commercial cooking recirculating systems",
while Section 502.1.3 seems to require that "odors" be exhausted to the
exterior".

Anyone care to try and explain ?

Thank you !


< < < 3

What "cooking" will they be doing? ICE asked if there will be a hood. I'll take that a step farther and ask if a hood is required due to the nature of the cooking operation.
 
@ ~ @

The type of cooking will be for a Full Breakfast & a Full Lunch.
Breakfast: Bacon, eggs, biscuits, etc..........Lunch: Lots of fried foods.

The appliances to be used have self contained hoods & suppression
systems.........The space that all of the cooking will take place
does not have an exhaust system to the exterior, rather, ...the space
has a traditional supply air & return air in it..........The hoods
on the appliances are intended to capture greasy particulates
produced during cooking ops..............FWIW, ...the whole building
is fully sprinkled !


@ ~ @
 
@ ~ @

The type of cooking will be for a Full Breakfast & a Full Lunch.
Breakfast: Bacon, eggs, biscuits, etc..........Lunch: Lots of fried foods.

The appliances to be used have self contained hoods & suppression
systems.........The space that all of the cooking will take place
does not have an exhaust system to the exterior, rather, ...the space
has a traditional supply air & return air in it..........The hoods
on the appliances are intended to capture greasy particulates
produced during cooking ops..............FWIW, ...the whole building
is fully sprinkled !


@ ~ @
Ahh... well, that is very clearly the issue then. The cooking area clearly needs to have some exhaust. Not really sure how it was not provided. Even with the integral grease capture systems on the appliances, mechanical ventilation is required by IMC Table 403.3.1.1 at the following rates:

1699289567408.png
1699289591172.png
 
2021 IMC 403.2.1 Recirculation of air. ..... 1. Ventilation air shall not be recirculated from one dwelling unit to another or to dissimilar occupancies.

The mechanical code has it's own occupancy classifications separate from the building code for this very reason. The occupancies are listed in the ventilation rate charts and do not necessarily follow the building code M, B, R, H, etc. occupancies. You can't take air from a salon and recirculate it to a bank even though they are both B occupancies.
By the mechanical code a food service establishment like a cafeteria is dissimilar to an office space, even if it is accessory to it. ASHRAE 62, which the ventilation charts are based on, has categories for these occupancies based on contaminant levels.
 
As questioned by ICE, Hood.
If you are cooking bacon and sausages you will need a Type I hood.
A Type I hood shall be constructed for grease.
That hood shall be vented to the outside.
Is there sufficient air flow up the hood?
Is there a return air grill in the kitchen, sucking the odors into the main air conditioner system?
Is there make up air in the kitchen for the hood?
 
Do the hoods have charcoal filters after the grease filters to reduce the odors? If so, they might just need to be changed.
 
These recirculating systems need to be listed to UL710B since they are in what I would consider a commercial kitchen. They would have a filtration system in them that needs routine maintenance. When these are used, each appliance under a recirculating hood adds 100 square feet to the general exhaust calcs from the ventilation tables in chapter 4. A 500 square foot kitchen with 4 appliances is figured at 900 square feet. At 0.7 CFM of exhaust per square foot, 630 CFM of general space exhaust is required.

710B recirculating hoods can be a great option for small kitchens or kitchens in locations where its hard or expensive to duct to the outside. The one catch is electric only appliances are allowed under them, no gas appliances.
 
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