# Venting clearances for a coffee roaster



## Yankee (Jan 31, 2013)

7000 btu gas fired coffee roaster w/6 in. B-vent pipe, where do I look to find the termination clearance requirements?


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## mark handler (Jan 31, 2013)

http://www.sonofresco.com/wp-content/uploads/stories/support/hood_installation.pdf


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## mark handler (Jan 31, 2013)

Customers should use double walled-positive pressure grease vent ducting. Those countries outside of this area may find this difficult to find. Therefore, IF your facility is concrete or brick you may consider 18 gauge welded pipe. The critical issue is the ability to withstand temperatures of up to 1400°F/ 760°C in case of flash fires.

One of the most important and critical aspects of your roaster installation is the use of an approved vent ducting system. This part of the roaster installation seems to create confusion when it comes to the ducting requirements. We have created this fact sheet to assist our customers in understanding the type of ducting and engineering requirements that are needed for a coffee roaster. The coffee roaster is connected to exhaust ducting which is an integral part of the roasting system. Its design will greatly affect the efficiency and performance of the coffee roaster as well as the quality of the coffee. The two main considerations in designing your ducting system are efficiently exhausting your roaster and the distance your ducting is to combustible/non-combustible materials.

Ducting Exhaust:

Coffee Roasters have an internal blower motor/fan to facilitate the exhausting of fumes to the outside. The blower motor/fan creates a positive pressure which by regulations/codes dictates a specific type of vent ducting is utilized. Normally, the coffee roaster’s internal blower can accommodate a 20-25’ vertical exhaust system without the need for any additional booster fans to exhaust the gases through the vent ducting. A direct vertical run is typically the most efficient and cost effective, although not always possible. Ideally, the roaster can be positioned so the duct is centered between the ceiling joists or rafters to allow the greatest clearance around the vent ducting. The design of the building may dictate the use of 45° or 90° elbows. Elbows will put a restriction on the airflow and may cause unwanted backpressure on the roaster. Termination booster fans are available to assist air movement if the exhaust system requires numerous elbows, is excessive in length, or has an excessively long horizontal run. Another option is to increase the diameter of the ducting.

Combustible/Non-combustible materials:

The roasting process creates smoke which must be exhausted to the outside of your building. In the event of a ducting/flue fire, the internal duct temperatures can exceed 1000° F (538°C), which could cause nearby combustible materials to ignite. Examples of these combustible materials are: wood walls, wooden floor joists, carpeting, plastics, etc. Different types or models of vent ducting (depending on construction methods) allow for an installation with increased or decreased distances to combustible and non-combustible materials. Generally speaking, the closer you want to install your roasting system to combustible material, the more expensive the ducting will be.

Note: Fires are typically caused by a failure to maintain a clean Roaster and/or the exhaust ducting. Regularly inspecting the Roasting System including the exhaust ducting and cleaning when the residue accumulation is equal to or greater than 1/8th of an inch (3 mm) will significantly reduce the probability of a roaster or ducting fire. See Owners Manual for further instructions and Cleaning Schedule.

The minimum requirements for vent ducting are: Single wall, welded seam 18 gauge ducting or Class-A Double Wall Positive Pressure Grease Vent Ducting. Diedrich Manufacturing, Inc. recommends UL certified (CE for European Union) Class-A Positive Pressure Ducting due to its superiority over the Single Wall welded seam 18-gauge ducting. Numerous companies manufacture Class-A Positive Pressure Ducting and the competing product lines have different specifications in regards to minimum distances to combustible and non-combustible materials.

Note: Under no circumstances should Class B or Spiral-wrap ducting be purchased.


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## cda (Jan 31, 2013)

So where are the wood fired pizza oven advocates that would require a vent a hood??

A Type I hood is required by code.

507.2.1 Type I hoods.

Type I hoods shall be installed where cooking appliances produce grease or smoke. Type I hoods shall be installed over medium-duty, heavy-duty and extra-heavy-duty cooking appliances. Type I hoods shall be installed over light-duty cooking appliances that produce grease or smoke.

SECTION 917

COOKING APPLIANCES

917.1 Cooking appliances.

Cooking appliances that are designed for permanent installation, including ranges, ovens, stoves, broilers, grills, fryers, griddles and barbecues, shall be listed , labeled and installed in accordance with the manufacturer's installation instructions. Commercial electric cooking appliances shall be listed and labeled in accordance with UL 197. Household electric ranges shall be listed and labeled in accordance with UL 858. Microwave cooking appliances shall be listed and labeled in accordance with UL 923. Oil-burning stoves shall be listed and labeled in accordance with UL 896. Solid-fuel-fired ovens shall be listed and labeled in accordance with UL 2162.

Cooking the beans???


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## Yankee (Jan 31, 2013)

Ok, more information: It is a counter-top unit. It is unlisted. Salesman said use a 6" Type B Vent. 7000btu. Vent connects directly, no hood.

I'd like to run away from this one.


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## mtlogcabin (Jan 31, 2013)

Is this a wood fired coffee roaster?


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## Yankee (Jan 31, 2013)

mtlogcabin said:
			
		

> Is this a wood fired coffee roaster?


Propane, and right now he thinks he's going to hook up the rubber supply hose and run it out the door to the propane bottle, but I'll deal with that later.


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## mark handler (Jan 31, 2013)

Yankee said:
			
		

> Propane, and right now he thinks he's going to hook up the rubber supply hose and run it out the door to the propane bottle, but I'll deal with that later.


run away from this one


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## cda (Jan 31, 2013)

Built-up coffee oils in the roaster are of no real consequence until they impede visibility or become a fire hazard. (In fact, a professional drum roaster requires hours of roasting initially to properly "season" the drum.) Do not clean your roaster too often... but do remove all the chaff from the top between every roast and SOAK THE ENTIRE CHAFF COLLECTOR ASSEMBLY IN DEGREASER PERIODICALLY TO REMOVE BUILT UP OILS- REDUCED AIR FLOW CAN OVER HEAT ANY ROASTER AND KILL IT.


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## Rick18071 (Jan 31, 2013)

I'm glad we are not allowed to inspect propane in PA, state law.


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## cda (Jan 31, 2013)

Yankee said:
			
		

> Propane, and right now he thinks he's going to hook up the rubber supply hose and run it out the door to the propane bottle, but I'll deal with that later.


and I am sure that the jets have been changed out for propane use


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## Daddy-0- (Feb 1, 2013)

If the unit is unlisted as you say it is you should have walked right then. The rest of the story screams RUN.


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## Yankee (Feb 1, 2013)

Daddy-0- said:
			
		

> If the unit is unlisted as you say it is you should have walked right then. The rest of the story screams RUN.


 Unfortunately I am not alone in this approval or my answer would be "submit proposal by a mechanical engineer". It may come to that, which would be JUST FINE with me.


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## north star (Feb 1, 2013)

*= =*

FWIW, ...if they truly are going to use propane as a fuel

source, then your Fire Code Official [ FCO ] should also

have some input on this set up / design.

*% %*


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## Yankee (Feb 1, 2013)

north star said:
			
		

> *= =*FWIW, ...if they truly are going to use propane as a fuel
> 
> source, then your Fire Code Official [ FCO ] should also
> 
> ...


    Uhu  :/  , , , , ,


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