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Kitchen Air Conditioning

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friartuck

Mechanical
May 31, 2004
402
Can anyone tell me if it is 'normal' to air condition a kitchen (In the UK

I have been asked to condition a kitchen, but over 25 years it is something that I have only come across once.

Is this a 'London' thing.

Likewise I would be interested to see if it is common overseas.

Incidentally, the spec calls for a controlled temperature of 30C which hardly seems worth it (I could understand it if they wanted 25C or so, but 30C seems too high)

Friar Tuck of Sherwood
 
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Depends on the cooking line. Here on BC, Canada we have a Workers Compensation Board requirement to not exceed 28C "wet bulb globe temperature" which, when you work out the mean radiant heat coming off the cooking line, the ambient humidity, and dry bulb temperature, many kitchens would need some amount of mechanical cooling. 90% of the time it's accomplished by very high air movement along the cooking line, but if it's an Asian style kitchen with some big wok burners and steam kettles, AC is almost mandatory to meet the WCB rules due to the mean radiant heat and humidity levels.
 
It's quite common to condition the kitchen - especially, commercial kitchens so as to give comfortable working conditions to the workers. I doubt whether there are any rules about the temperature, but in my opinion, 30 deg C should be fine. Don't forget to take care of negative pressurisation so as to avoid food smell going out to adjacent areas. Also, take into account the higher outside air quantities that would be a common feature of kitchens due to the difference in air quantity between exhaust & supply.

HVAC68
 
Unfortunately, there are still some non-air conditioned kitchens, but that should be remedied wherever possible. HVAC68's recommendations are good. The idea of kitchen workers dripping sweat into the food is not good.
 
Of course, there used to be an apocryphal story that San Francisco sourdough's special flavor had something to do with sweat...

While kitchens are expected to be hot, 30ºC is pretty hot, when facing a set of 20,000 BTU burners for 8hrs a day.

Additionally, you should also consider that higher ambient temperatures increases the growth rates of bacteria, so a 28ºC or cooler kitchen is probably more sanitary.

TTFN



 
Agree with HVAC68, cooling is common is kitchen spaces however the varying volume of introduced air due to the specific density changes across the psyc chart mean it is preferable to provide invertor drive to the supply fan motor linked with controls to maintain the 85% negative pressure. This is really important for kitchens with direct openings to the restaurant area.

There is no upper limit at the moment for working environment temperatures however this is about to change with the revision of the Health & Safety at Work acts. They will limit the temperature to 28degc for a set exposure time, however you should be able to get around this by providing cool zones say from a DX unit (see mitsubishi stainless steel range designed for greasy environments) blasting ccol air into a zone.

Be careful though that kitchen staff can not adjust the air direction towards the canopy and affect the plume from the cookline.
 
30 deg. C is not too high for kitchen if you consider kitchen conditions. I think that demand is put just to avoid heavy direct cooling the kitchen.

If you use "neutral" air for ventilation which can be, say 25-28 deg C during summer and 22-23 during winter (when I say neutral, I mean air with enthalpy that "cover" just heat ventilation losses/gains not transmission losses/gains)- you can reach 30 deg C by regulating the number of air changes (which, of course, also has to be within legislation limits), not by direct cooling.

That can also mean VFD on exhaust only with ordinary central air supply, while underpressure can also vary within acceptable limits.


[sunshine]
 
Commercial kitchens require significant makeup air for the hoods over equipment. When determining the max air temp for the comfort of the staff, keep in mind that if you use transfer air from the dining area, there should additional cooling effect from the air movement in the kitchen. Determine the amount of conditioned transfer air required to keep the kitchen cool enough for the workers. Then determine what hoods can be compensating verses standard, while ensuring sufficient conditioned transfer air.

The problem is if this is not a restaurant with seating, then there may not be enough conditioned transfer air to get the required cooling for the kitchen. I have only seen dedicated air conditioning for kitchens when the kitchen was a stand alone operation without a dining facility.
 
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