Question about Hoods

I have a dilemma on my hands. We’re looking at a building with limited hood space. Right now it has a 8foot class 1 hood. We either need to add on another 5 feet or find a hod solution like one in the picture. Can anyone tell me if theres any options for adding on to an existing hood system or what type of hood is in this picture. Thanks

that hood is a Giles brand “ventless” hood - provides no make-up air - think of it as a glorified simple hoousehold kitchen exhaust fan…will remove smells & some grease…not designed for a true high volume big a$$ oven…not cheap either…used in place where traditional exhaust isn’t an option, like office buildings, hi-rises etc…

you can find them on ebay from time 2 time…

you can easily extend your hood if you know a metal fabricator,they can plasma-cut youre existing hood and extend it another 3 feet in each direction.

Arduous…In some jurisdictions if you modify your hood, it must be re-certified…Sometimes that can be more costly than starting from scratch…Best to enquire as to the rules in the jurisdiction in question…

HI North Shore:

Patriot has it correct:

Note that type hood can only be used on electric ovens as no carbon monoxide is exhausted,

Ardus is correct in that hood can be modified. But as Royster notes, that will change the required CFM of exhaust and the required make up air and as he states re approval by your building department.

If yours is not a certified hood That is has been tested by UL or ETL and has a certification certificate there is a possibility that under the latest rules your exhaust rate may have to double. If you have a certified hood any modification will void the certification

Ventilation is always opening a can of worms.

If you would like to Email Mail me describing your situation I will try to sugges the best solution.

George Mills

Arduous…In some jurisdictions if you modify your hood, it must be re-certified…Sometimes that can be more costly than starting from scratch…Best to enquire as to the rules in the jurisdiction in question…

I thought the saying was better to ask for forgiveness (if they notice) than permission(or permits) :lol:

Yes, except for the fact that an “overzealous” building inspector can shut you down while you are “negotiating” forgiveness…

Old post but how does a regular hood provide “make up” air?

Hi PJ:

For pizza set ups we always use a compensating hood. Our latest model brings in unheated outside air and drops it down all across the back of the oven to within a couple of feet of the floor. That air is then deflected upward around the oven and is discharged out the hood.

This system is certified to only require 800 CFM of air from the inside of the building for the average pizza oven. That then requires no make up air unit as the 800 CFM can be supplied by the HVAC system saving a lot of money.

George Mills

That sounds pretty cool! How much could one expect to pay for a setup like that assuming a straight shot up through a drop ceiling to a flat roof?

Hi PJ:

The unit I described ,used for a double PS-360 MM oven or up to a triple stack of XLT 3250 or MM PS 555 or set of Y-600 deck ovens would sell for $5,815.00 + Shipping. Actually about the same price as for a regular hood with a make up air unit. The big savings is that you don’t pay the probably $2,000.00 per year to run the make up air unit and you do not have your A/C fighting the hot air a make up air unit dumps off the hot summer roof into you Kitchen. That could be several thousands more saved over the summer.

George Mills

Thanks George. Do you know where I would be able to find the code for NJ to figure out if a hood is required, if make up air is required, etc. Is it dependant on BTU/h or?

Hi PJ:

Phone your local building department they can tell you the code. I have never been able to find a place where I can find local variations of the code. I refer to the national building code. Local jurisdictions can add more stringent regulations to the code but rarely specify less than the national code.

The national code requires hoods over all equipment that raises the temperature up to 250 degrees be it electric or gas heated. It is required by the code to replace any air exhausted from the building including the air exhausted from rest rooms. That air cannot be less than 10 degrees below room temperature. That requires if a make up air unit is used it will have to have a built in furnace to warm the air when outside temperatures are less than inside your building. The air supplied by a make up air unit is not required to be cooled. Actually that is a big problem with make up air units. During hot summer days a make up air unit is pouring thousands of CFM of super hot air off the roof into your kitchen. Air conditioners most often are not sized to compensate for all that hot air as the cool air created is being pulled out the hood.

A properly designed ventilation system for most pizza shops can operate without make up air and consumes little of your A/C.

We can equip a pizza shop with 3 or even 4 stacks of the largest conveyor ovens so they can operate without make up air and only pulling 880 CFM of air conditioned air from a building.

George Mills – pizza

This is interesting. I will have to call our local building dept I guess (hard to get ahold of!) I noticed a new shop open up with a double stack of Y600s. They have a draft flue with no hood. This is a very up scale stringent town and NJ as a state is fairly stringent as it is.

We are looking at a double stack of Baker’s Pride GS805 - total of 120K BTU.

Hi PJ:

A flue pipe ducted out the roof with no hood is not up to the national building code and is also dangerous to the health of the workers.

The national building code calls for a hood and ventilation system over any cooking device that raises the temperature of the product to 220 Degrees or more.

The flue pipe itself only extracts a portion of the carbon monoxide and unburned gas fumes. Workers can develop severe head aches and even carbon monoxide poisoning unless there is some other system that is effecting rapid changes of air in the work area.

Also a set of deck ovens gives off an enormous amount of heat and that does not go out the flue pipe. You would probably have to run an additional five or more tons of A/C when the ovens are on to counteract the heat given off by the ovens.

A well designed ventilation system is the best and most economical solution.

George Mills