Interesting Oven Hood

There is a Little Caesar’s opening near us and it has an interesting hood design that appears to be specifically for pizza ovens. Rather that a hood that covers the entire top of the oven, this one just had am opening for each of the ends of the conveyor oven. Which makes sense, as the heat and combustibles exit there.

I have seen George’s hood and it is an interesting idea. But this one intrigued me even more because it seemed specifically designed for the oven. Anyone know what I am talking about?

I have a single hood right over my oven doors. Its less then half the depth of the ovens and same exact width. Its basically just for when the doors are open.

Charles, I’ve seen them refered to as an eyebrow hood. Most ovens have some heat coming off the top that this type of hood won’t pick up. Also if used on a triple stack, it’ll miss some of the heat from the middle belt and alot of the heat from the bottom belt.

That sounds odd to me to only cover the ends. I agree that the ends put off the most heat and gas, but the middle of the oven still puts off a lot of residual heat. Not having a hood over that section seems like it would make for a hot kitchen; unless of course that hood has enough suction power to reach the middle. But that still doesn’t make sense. Why go through all that trouble?

Not sure. Little Caesar’s uses it for some reason. Maybe the middle DOES put off heat, but not enough to justify all the makeup air. As it has been pointed out on the TT, the heat off the top and closed sides is radiant heat and not captured except by removing and air it heats. I would bet 90% or more of the volume of heated air is coming out the open ends. And what little air heated by the closed sides would migrate to the vents on the ends by the flow of air pressure in the kitchen (positive) to the vents (negative).

There must be a reason they designed it that way. I just cannot find any science behind it.

I had a hood like that 4 my 1st CTX system…believe u can only use it 4 electric ovens…did a good job 4 me, but then the CTX is well insulated…

by the way, anyone want 2 buy a dbl set of CTX’s …new store is an old MM360 set up…(finally got a terrific bake out of it tho…)

I think it is just for electric. I found one at http://www.duoaire.com/Products_KEH-EO.html. It does not list one for gas, probably because the CFM is so low.

Here’s what it looks like (form AMS):

http://www.amsenterprises.com/newpr.GIF

Hi Dewar:

Pizzafanatic is correct, the code does not care about extracting heat just cooking vapors, That type eye brow hood does not extract heat from the top ,front or back a lot of heat remains in the kitchen.

We designed and sold a 100’s of those type hoods back when the regulations were simple.
Today that type hood would be required to exhaust 3000 cubic feet of air per minute. It would need ether an 18 or 20 ton air conditioner Or a 3000 cfm make up air unit to compensate for the air being pulled out of the building. If A/C were used you would be throwing out 3000 cfm of expensive cooled air per minute.
If you used a makeup air unit it would cost about $4,000.00 to $5,000 to install and another $4,000.00 per year to operate depending on your location. Also during the summer a make up air unit would be pumping 3000 cfm of very hot air off your roof into your building requiring more A/C to compensate for that heat.

The hood we have that was specifically designed to overcome the problems outlined above extracts The maximum amount of heat from all around the ovens but only takes 720, 800 or 880 cfm of air from the building depending on oven size. This system costs about the same as the Eye brow hood used with a make up air unit or with a larger A/C system. But it costs thousands less than ether of those systems in yearly operating costs. Reason: our system does not have to heat or cool any air.

Paul points out that the eye brow hoods will not work efficiently on triple decks. He is correct the cfm of the exhaust system has to be cranked up so high to capture from the bottom deck that all the heat is usually pulled out of the top oven and often the bottom one is not sufficiently captured.

Additional notes the eye brow hoods work the same and require the same exhaust and make up air be the ovens gas or electric.

Also note kitchen vent elation is not required by code to address heat in the kitchen it is required by code just to extract the cooking vapors. Cheep vent elation systems meet the code but do not take out much heat and usually require a vast amounts of make up air.

If not done properly the ventilation system can leave your kitchen uncomfortably hot and cost thousands per year to operate.

George Mills

Well, unless I have more concrete information, I am not going to guinea pig something. I will rely on your expertise, George. I sent my HVAC guy the hood specs you sent me for his calculations.

Hi Charles:

If your HVAC guy uses the standard code for hoods he will come up with different figures than we show.

The difference is, there is a section of the code that allows ventilation systems to be tested by the major testing laboratories UL or ETL to determine if what they claim is so. If the submitted hood systems perform better than the standard code they are certified by those organizations and are allowed by code to be installed and operated at the better than normal code specifications they use

There is no way on paper to determine the efficiency of any hood ventilation system that operates at less than standard code without having the facilities to test the said hood under controlled conditions

George Mills