Kitchen hoods not working properly

Help it is "stupid hot" in the kitchen...
Does anyone know about how to set up an exhaust hood properly?
We keep it clean and all the repairmen say is" well the fan is running..there isn't much we can do".
This is THE hottest kitchen I have ever worked in...there must be something we can do.
PLEASE HELP....
Thanks

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[Jim]

Jeff,
Sorry to hear about the risin' mercury. Do you know if you have a "make-up air supply"? Make-up air replaces the air that is being pulled through the exhaust system. The make-up air works in reverse of the exhaust; it generally pulls air form the outside. Although outside air is not cool, it will be measurably cooler in the kitchen as the extremely hot air is replaced with air that is not as hot. When you have an exhaust system without make-up air, you create near-vaccum like conditions, in that the flames from your burners and ovens are drawn to the source of air... in this case it would be up towards your exhaust, and that is why it can get so darn hot.
If make-up air isn't going to be part of your solution, a ceiling mounted paddle fan (or 2) helps stir up the air a bit.
Good luck.

[CookinFast]

The best thing for that is a new ventilation system. Maybe it is time to get a new ventilation system. I would suggest getting a hood with a tempered make up air supply. You can always tell your boss that the hood is a fire hazard and OSHA will fine him. I have a Captiveaire hood and it works really well. We flip a switch, and then we have cooled or heated air.
Hope this helps,
Cookinfast

[emhahn]

Your fastest and best remedy is to contact your fire marshall. The fire marshall in your community is the man who comes in and inspects your hood.

I agree with everyone else here, talk your boss into getting a new hood, a new vent, new filters, or whatever it is that's causing the heat to be "stupid hot."

It's a fire hazard.

Eric

[michigan dave]

Just because the fan is working doesn't mean the system is exhausting. The make-up air is a good start. Usually this comes form some sort of a grill in a door or some such other place where air can be sucked into the kitchen (maybe from the front of the house) Has anyone checked the stack (vent pipe) to make sure there are not obstructions such as a birds nest or a big wasp nest. Is the fan working at the proper speed. If you hold a cigarette or piece of incense (some source of smoke) up near the intake hood is it pulled immediately up into the hood. I would look to trying to figure out what the real problem and not just throw money at it . New hoods and ventilation systems are not cheap. If you save the boss $$ he'll probably be real happy. Maybe your filters have become permanently clogged. If you remove them for a while does the situation improve? Has someone shut off the make up air source. Look around for something that looks like a big air register in your house, if it has a lever on the side of it it likely works shutters that can be open or closed - make sure they're open. Just some ideas you might want to check out.

[panini]

All the answers seem to make sense. I have always prefered power make-up air. The fan may be two speed or not working properly. Put a couple of pots of boiling water under different places under the hood. Kick you hood on and you should see some sort of vortex looking puppies coming from the steam from the boils. You can also do this with smoke. If the smoke or steam flounders and does not go right up the hood you make not be working properly or your system does not have the proper cfm to exhaust the air. Getting a new hood is not something an owner wants to hear. Usuallt the hood has nothing to do with it. It's the fan for exhaust and make-up air. hese can be replaced with larger units without changing out the hood.
Find yourself a doctor of naturothopy and acupuncture. You can get a couple of needles put in your ear and will cool you during the hot times. I know a couple of cooks doing this with great sucess.

[Kenneth]

Hi Jeff,

I can’t believe that the “repairman” said it was working because it was turning. Many problems could let it run but not move enough air. It sounds like the bigger problem is with the “repairman.” You need an HVAC technician. It could be a nasty and smelly job. Not all HVAC companies take them.

Assuming nothing on the system was changed before the problem started, here are some possibilities, that let could keep running but not working.

Off value capacitor
Low or high voltage
Bad belt
Bad bearings or bushings
Bad pole
Phase imbalance or reversal
Bad motor protector
Bad or out of adjustment pulley
Etc

If the ventilation system had been worked on before the problem;

Fan blade damaged, wrong size, reversed or wrong rotation
New motor too small or large (yeap, too large)
Housing reassembled improperly
Wrong capacitor
Controls improperly wired
Etc

The problem could be with the building or the make up air as others have said.

The majority of the problems I have seen require a simple inexpensive belt change. This is so common that I would buy an extra belt and leave it in the unit for the next time. The belt should be adjusted so that there is 1 inch of play in the belt.

If you try to fix it, make sure the power is turned off. Not just that the fan turned off. Breaking 1 line is enough to turn it off but you could still loose a finger. All the lines must be broken.

I would not recommend replacing the hood system only because of this problem. I can’t imagine a component failure that could make that worthwhile. It’s like replacing a car because of a bad radiator. But if you want a new car, go for it.

If you want a new hood system, I’d go for the high tech ones. The variable speed intelligent ones. A sensor determines when and how much ventilation is needed. The energy savings payback is suppose to be about 2 years. Make sure you get a technical manual for it, not just an owner’s manual. Then don’t let it out of your site. Techs like manuals.

I would recommend that you make sure the refrigeration condensers are clean. The high temps are tough on the ones with the condenser on top. When they over heat, the oil breaks down and eventually the compressors fail.

Hope this helped,

Kenneth
www.RefrigerationSecrets.com
www.refrigeration-repair-tips.com