air conditioning a kitchen

[multisync]

We got a call to to look at a temporary kitchen which is in a marquee.

The size is about 12 x 15m square and 6m at the centre.

As it's a full working kitchen for approx 100 workers it has 2 coldrooms and one freezer room plus all the usual ovens hobs grills etc etc.

So where on earth would we start to size the gaff? Obviously we aren't looking to make it 20 deg's but on friday it was 37 in places and they were worried on H&S grounds.

[Yuri B.]

Hi. You have not mentioned what for exhaust ventilation they have.

[Yuri B.]

Aproxim 100 souls in such a space is a bit too much too.

[frank]

As it's temporary, and contains a lot of radiant heat devices, (cookers, hobs, grilles etc.) the only thing in my opinion would be a full fresh air system. Let the cooking extract determine the amount of air volume you require and work from there.

If you keep the input air just short of the extract volume, say 10% you will prevent cooking smells spilling out.

I would aim for a supply air temperature of between 15 - 18C, using staging for capacity control.

[Yuri B.]

Only air ducts, fans, their grilles have been very possibly neglected and now are fairly covered with grease.

[multisync]

Aproxim 100 souls in such a space is a bit too much too.

It's a kitch to provide food for 100 workers. It is not a restaurant space.

[multisync]

As it's temporary, and contains a lot of radiant heat devices, (cookers, hobs, grilles etc.) the only thing in my opinion would be a full fresh air system. Let the cooking extract determine the amount of air volume you require and work from there.

If you keep the input air just short of the extract volume, say 10% you will prevent cooking smells spilling out.

I would aim for a supply air temperature of between 15 - 18C, using staging for capacity control.

We were thinking of one or those marquee coolers you see at various outdoor events. I doubt we will maintain a temperature but hope to take the top off the temps. The fridges and freezers are struggling and chef is worried about food poisoning.

We guessed 100kw but will suggest 40kw

[Abby Normal]

big evaporative cooler, go all outside air , purge the heat out of it

[Abby Normal]

this is a tent?

[chemi-cool]

Evaporative cooler is no good in kitchens, its humid enough as it is .

A 100% fresh air AC unit will do the job better and a few extract air fans on the other side.

Ducts tend to get covered with oil and kitchen dirt.

[Abby Normal]

Evaporative cooler is no good in kitchens, its humid enough as it is .

A 100% fresh air AC unit will do the job better and a few extract air fans on the other side.

Ducts tend to get covered with oil and kitchen dirt.

This sounds like a tent, and it traps the heat, so too bad they do not have roof vents in a tent. If they do have hoods for the cooklines then the hoods are pulling the humidty generated by cooking out of the space, but there is still radiant heat from the cookline and items like refrigerators etc give off heat as well.

Evaporative cooling is ideally a 100% outside air system. It has nothing to do with the humidity generated inside of a kitchen as it is a displacement effect.

Evaporative cooling applied to recirculated indoor air is a humidifier, you want to humidity the outside air to cool it off, blow it into a hot space, cools the space and then displaces humid air out of the space.

A rainy climate like the UK gets perceived as humid but when you look at dewpoints you get in the outdoor air, it is not a humidity challenge at all.

You can get huge tents to double as mess halls, ballrooms etc, seen people use duct sox and a couple big package units for this type of application

[multisync]

Here is a pic of the tent.

[Abby Normal]

It traps the heat

Gable vents on each end would make a huge difference, even if one end was a just a prop fan exhaust and the other end was a filtered intake.

You may want to try a series of spot coolers as well, something that gets air directed to where the people are working

Get the duct sox with the nozzles, have the nozzles aimed at the floor of the aisles seems like there are two aisles going down the length, you need to do some grade school geometry here. Blow evaporatlvely cooled outsde air into the duct sox. It is going to spot cool the people in the aisles. Have relief vents on the two gabled walls up high. You will be spot cooling the people and purging out the heat at the same time.

Trying to put something inside that recirculates air is going to need twice the capacity as something that purges.

Best attempt for recirculating air is spot coolers, just you direct them to where the people are working.

[Abby Normal]

I think with the UK climate, even filtered outside air ( instead of cooled air) getting blown down at those aisles will be infinitely better than what it is like in there now, the convection is going to cool the people working and you are still pruging the heat out of the tent.

Right now it has to be getting a lot hotter inside than it is outside.

It would be like the difference between a sweltering day in still air vs what is perceived as a cool breeze. If you ever visited anywhere hot and humid, this would be hitting home

[Yuri B.]

To add a trifle to the so exhaustive comments - maybe also it is worth cover the (at least the southern part of the) construction, which seems to be half-transparent, with sun light reflective foily cover (like they put on window glasses)?

[Yuri B.]

As solar rays may also drive up heat inside - at sunny days (greenhouse). I dont know however nothing about the material these tents are made of - it may already be, "ray repelling."

[al]

could this type of fabric ducting help you out? attached to some large split ducted units utilising fresh air?

http://www.refrigeration-engineer.co...&pictureid=706




al

[Yuri B.]

Maybe, also, provide separate extraction line(s) for the off air of the condensers - both of the cold rooms and the freezer?

[back2space]

I agree with the above comments, lots of fresh air and if possible some extract fans. You need to pull that heat out and introduce fresh outside air that is always going to be cooler than the 37C you mentioned in places.

The fabric ducting sounds good as well and will be filtered quite well too.

[Abby Normal]

could this type of fabric ducting help you out? attached to some large split ducted units utilising fresh air?

http://www.refrigeration-engineer.co...&pictureid=706




al

get them with nozzles, to blast the air down and spot cool the occupants, you would not want the diffuse air leaking out all over the place.

You push air down it will force air up and if you have high vents, you get high level air moving out

[lowcool]

im with abby,big swampy with lots of air and general relief,hood design affects the effect also.cant say ive seen refrigerated used in a commercial situation

[Makeit go Right]

Phew, a tricky one. Being temporary, no one will want to pay big time for a proper hood solution and aircon supply. Big money.

Practically, you should look at extracting from high level. Get a long duct through the tent, under the apex, and a big fan on the outside. (possibly a bifurcated fan, with all that greasy air.)

You could put a couple of those big 15kW portable aircon units (telephone box with hoses out the top/front) in there to help with the general air temperature. More expensively, you could hire a chiller and AHU to push cool air into the tent. (Andrews Hire?)

You could also put a few desktop fans around the place (but secure so they don't fall into the chip-friar) to deal with that radiant heat from the kitchen equipment. But, the cooks are used to this kind of thing.

[Magoo]

Lots of fresh air, minimal pressurization,natural exhaust through openings.
magoo

[lowcool]

come to think of it,if this was aust it probably wouldnt be there.me thinks the powers that be would shut it down.pics of wash,cooking areas would be interesting to see

[multisync]

come to think of it,if this was aust it probably wouldnt be there.me thinks the powers that be would shut it down.pics of wash,cooking areas would be interesting to see

Why would they shut down a kitchen?

[frank]

. (Should be bifurcated, really.)

Any idea why?

You could put a couple of those big 15kW portable aircon units (telephone box with hoses out the top/front) in there for anyone sitting down (guess they sit off to the right hand side, yes?)

I thought we were talking about a kitchen???

But it would be better to get some more tables and chairs so the diners can eat outside, once they collect their plateful from the cooks.

Have we lost the plot a little?

For the cooks -- poor souls -- they need lots of desktop fans that are not falling into the chip-friar. But, they are used to this kind of thing.

Desktop fans in the kitchen....

[brunstar]

by the looks of the situation due to the temperature at which the col rooms are it seems they are under more load than they should be.

you would be looking at at least 50kw which works out at 250 watts persquare meter, with no insulation on the tent.
Air changes at the top of the tent and cooling from low level shoul do the trick, i can't see it being cheap though.

[lowcool]

Why would they shut down a kitchen?

first time ive used a quote will see what happens. building codes & as you mentioned health,all temporary tents i have seen are scout camps,sausage sizzles and small events(one could say the clipsal 500 is small event as is only a few days).but apart from getting away from the point i rest with whats said about evaporative a/c.i imagine your ground water temperature would be fairly cool also.bon appetite