# Type I Hood fan shut down?



## mtlogcabin

We have some inconsistency in shutting down Type I Hood ventilation system upon activation of the suppression system. Some jurisdictions shut down the entire system others just the make up air and leave the exhaust on regardless of the type of extinguishing sytem. Our jurisdiction has been under the IFC since 2002 while every one else in the state remained under the UFC. They are now adopting the 2009 IFC.

This was all I could find

2006 IFC 904.11.3.1 Ventilation system.

Commercial-type cooking equipment protected by an automatic carbon dioxide extinguishing system shall be arranged to shut off the ventilation system upon activation.

Our own FD required the supply to be shut down and the exhuast to remain running but I can not find a code section to back this up


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## TJacobs

Since CO2 extinguishment is mainly by oxygen reduction and a little cooling, I would vote for shutdown of exhaust and supply (what that code section says) to allow the concentration of CO2 to stay as high as possible for as long as possible in the hood and duct.


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## pwood

here's another opinion" calif mech code(u.m.c.) 511.2.3 "a hood exhaust fan shall continue to operate after the extinguishing system has been activated..."


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## Marshal Chris

IFC (Based upon NY)

610.4 Inspection and maintenance. Commercial kitchen exhaust hoods shall be inspected and maintained in accordance with NFPA 96.

NFPA 96

8.2.3 Exhaust Fan Operation.

8.2.3.1 A hood exhaust fan(s) shall continue to operate after

the extinguishing system has been activated unless fan shutdown

is required by a listed component of the ventilation system

or by the design of the extinguishing system.

8.3.2 When its fire-extinguishing system discharges, makeup

air supplied internally to a hood shall be shut off.


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## mtlogcabin

I see now see where the confusion has come from because the ICC does not reference NFPA 96 in the IBC, IFC or the IMC.

The ICC's new certification for FK Pre-engineered Kitchen Fire Extinguishing System Technician list it as a reference needed for the test. 

Now that makes sense to test an inspector on a document he is not authorized to use.


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## TJacobs

Check out the following in 2008 NFPA 12:  5.2.2.2, 5.3.5.2, Annex B.3


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## TJacobs

A code-compliant CO2 system would have a damper in the ductwork, again the assumption is to keep the CO2 concentration elevated.  If there is indeed a damper at the top or bottom of the duct it might not matter if you leave the exhaust on, but it says to shut the system down.

[F] 904.3.3 System interlocking.

Automatic equipment interlocks with fuel shutoffs, ventilation controls, door closers, window shutters, conveyor openings, smoke and heat vents and other features necessary *for proper operation of the fire-extinguishing system* shall be provided as required *by the design and installation standard utilized for the hazard*.

904.11.3 Carbon dioxide systems.

When carbon dioxide systems are used, there shall be a nozzle at the top of the ventilating duct. Additional nozzles that are symmetrically arranged to give uniform distribution shall be installed within vertical ducts exceeding 20 feet (6096 mm) and horizontal ducts exceeding 50 feet (15 240 mm). *Dampers shall be installed at either the top or the bottom of the duct* and shall be arranged to operate automatically upon activation of the fire-extinguishing system. When the damper is installed at the top of the duct, the top nozzle shall be immediately below the damper. Automatic carbon dioxide fire-extinguishing systems shall be sufficiently sized to protect all hazards venting through a common duct simultaneously.


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## cda

from NFPA 17A  2002 edition

4.4.3.5  Exhaust fans and dampers are not required to be shut down on system actuation as the systems have been tested under both zero- and high-velocity flow conditions.

plus as alway install per manufacutre, which i sure states to let the exhaust ru, but not sure if they tell you to turn the make up off??


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## TJacobs

cda said:
			
		

> from NFPA 17A 2002 edition 4.4.3.5 Exhaust fans and dampers are not required to be shut down on system actuation as the systems have been tested under both zero- and high-velocity flow conditions.
> 
> plus as alway install per manufacutre, which i sure states to let the exhaust ru, but not sure if they tell you to turn the make up off??


17A is for wet chemical systems and does not apply to the OP.


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## mtlogcabin

> 17A is for wet chemical systems and does not apply to the OP.


I was looking for something in the code that was generic to all systems (like NFPA 96) so I would think 904.11 would get me to each specific system since I can't use NFPA 96 unless the manufactures installation instructions reference it. 

904.11 Commercial cooking systems.

The automatic fire-extinguishing system for commercial cooking systems shall be of a type recognized for protection of commercial cooking equipment and exhaust systems of the type and arrangement protected. Preengineered automatic dry- and wet-chemical extinguishing systems shall be tested in accordance with UL 300 and listed and labeled for the intended application. Other types of automatic fire-extinguishing systems shall be listed and labeled for specific use as protection for commercial cooking operations. The system shall be installed in accordance with this code, its listing and the manufacturer’s installation instructions. Automatic fire-extinguishing systems of the following types shall be installed in accordance with the referenced standard indicated, as follows:

1. Carbon dioxide extinguishing systems, NFPA 12.

2. Automatic sprinkler systems, NFPA 13.

3. Foam-water sprinkler system or foam-water spray systems, NFPA 16.

4. Dry-chemical extinguishing systems, NFPA 17.

5. Wet-chemical extinguishing systems, NFPA 17A.


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## FM William Burns

I believe your on the right track MT. Personally I have 96 so the only way to get there IMHO is using that and and the specific system manufacturer's material.

BTW congrats: TJ it was a great game


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## Builder Bob

Little known fact, the UL listing of equipment is based on NFPA 96......... So the manufacture's specifications are generally going to mirror NFPA 96 requirements.


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## cda

Our own FD required the supply to be shut down and the exhuast to remain running but I can not find a code section to back this up

from NFPA 17A 2002 edition

4.4.3.5 Exhaust fans and dampers are not required to be shut down on system actuation as the systems have been tested under both zero- and high-velocity flow conditions.

I think this answers half your question

icodes allow you to reference other codes  102.7 IFC 2002 edition

also from NFPA 96 : 2008 edition

8.3.2  When its fire-extinguishing system discharges, makeup air supplied internally to a hood shall be shut off.

suggest you call someone you trust in the fire extinguisher business and ask them the question see if it is in the manfacture installation instructions also.


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## peach

IBC 904.11.2: System interrconnection.  The actuation of the fire suppression system shall automatically shut down the fuel or electrical power supply to the cooking equipment.  The fuel and electrical supply reset shall be manual.


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## fireguy

The manufactures of UL 300 suppression systems have their systems tested and listed to control a fire with the exhaust fans on or off.  But, if the exhaust fan is on, the following benefits are noted

1. The smolke is pulled up the duct, increasng visibliity

2. The heat is pulled out to the kitchen, increasing comfort of the fireman.  I will say I never noticed how hot a fire was while I was fighting it, so this point is moot.

2. The suppression agent is pulled up the duct, controlling any fire in the duct better.

Intake air is different, we do not need any more oxygen delivered to the fire.


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## TJacobs

Folks, the OP is questioning CO2 suppression...UL300 does not apply...the ventilation system will affect the concentration of CO2...wet chemical systems are different...


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## beach

I don't know if his specific question was regarding CO2 systems or the only code section he could find referenced CO2.......


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## cda

"""""""""""""""""           I was looking for something in the code that was generic to all systems (like NFPA 96) so I would think 904.11 would get me to each specific system since I can't use NFPA 96 unless the manufactures installation instructions reference it.  """"""""""""""""""


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## TJacobs

The point is that even if you could use 96, the suppression standard could trump it.  It's not always as easy as we would like it to be.


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## mtlogcabin

I was refering to all systems.

When I did an I-Quest word search the CO2 system was the only one that popped up.

I see where I need to order a couple of NFPA Standards next week. They will probably put my budget in the red for the end of the fiscal year :cry:

Thanks for all the help


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## TJacobs

NFPA appreciates your "donation"...


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## FM William Burns

View them for free and save

MT,



Doing my part to save your department from going 3rd party…lol



Remember you can view all NFPA codes and standards for free.  



*Step 1.* Click on a code or standard here: http://www.nfpa.org/aboutthecodes/list_of_codes_and_standards.asp



*Step 2.* Click on the “*View the document online (read only)”*



*Step 3.** Create a “free” account and follow the promps.*


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## Glennman CBO

Wouldn't the running exhaust fan pull the suppression agent up the vent instead on letting it suppress the fire at its source?


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## peach

well then look in IBC Sec 904.3.3 System interlocking.

904.11 items 1-5 shall be installed in accordance with the referenced standard.. NFPA 12,13, 16 17, 17a


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## cda

Wouldn't the running exhaust fan pull the suppression agent up the vent instead on letting it suppress the fire at its source?

with a normal fixed pipe set up, you have

1. nozzles protecting the cooking area

2. nozzles protecting behind the filters

3. nozzles protecting into the duct work to the roof

the nozzle that protects the duct to the roof normaly has a unlimited length coverage

t


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## cda

http://www.youtube.com/watch?v=c91N3MmBbEg&feature=related


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## Marshal Chris

Let me ask a question, does 610.4 of the IFC say this:

610.4 Inspection and maintenance. Commercial kitchen exhaust hoods shall be inspected and maintained in accordance with NFPA 96.

Or is that a NY enhancement only?


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## FM William Burns

MC,

Think that's a NY state of Mind......... thing


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## Marshal Chris

Well than that would explain the crickets I heard after my post.


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## beach

This is from the Ansul UL300 manual (type l duct systems were required to be retrofitted to UL 300 standards, CO2 or Automatic fire sprinkler systems in California by Jan. 1st 2008. Around here, 99.9999 % of the new systems are UL300, actually.... I've never seen a new system that was other than UL300) :

"Exhaust fans in the ventilating system should be left on. The forced

draft of these fans assists the movement of the liquid agent

through the ventilating system, thus aiding in the fire suppression

process. These fans also provide a cooling effect in the plenum

and duct after the fire suppression system has been discharged.

The system is UL listed with or without fan operation.

Make up or supply air fans, integral to the exhaust hoods being

protected, shall be shut down upon system actuation"


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## peach

Then Ansul needs to coordinate with the IBC committee to get it changed!


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## beach

Get what changed? Section 511.2.3 (California Mech. code) states ".... A hood exhaust fan(s) shall continue to operate after the extinguishing system has been activated, unless fan shutdown is required by a listed component of the ventilation system or by the design of the extinguishing system"

This is California code, mind you, I'm not sure of the others......the Ansul manual makes sense and the system is UL approved either way


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## peach

Ok... well it works in California..  not places under the IBC


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## beach

"IBC 904.11.2: System interrconnection. The actuation of the fire suppression system shall automatically shut down the fuel or electrical power supply to the cooking equipment. The fuel and electrical supply reset shall be manual."

Not familiar with the model IBC.... if you were refering to the above quoted IBC section, I believe that relates to the actual "cooking equipment" such as electric salamanders, electric fryers, etc. not the electrical for exhaust fans.


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## peach

since the electrical supply also applies to the lights in the hoods, it includes the fan.


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## beach

Not in my opinion, I believe the IBC wants the actual "Cooking equipment" (as you stated in IBC section 904.11.2)I read "cooking equipment" as the equipment that cooks the food  .... to turn off. It makes sense to me that if the food that is being cooked is on fire, it doesn't need the heat source that started it to still be on, of course.........

I can't get rid of "read read" it only shows up after the post.....


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## FM William Burns

Valid opinion there Beach. Back in the day sat in on some initial 300 testing and additional rationale to require all fuel and power shut down (with exception to exhaust fan) was to prevent re-ignition of ignitable vapors when equipment was moved and nozzles or flow points were being dialed in for angular coverage. Eliminating heat and fuel sources aids in the prevention of potential re-ignitions if equipment gets moved.


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## cda

we are talking about an exhaust fan that sets outside the building

and the electric power runs on the outside of the unit

most fires I have seen are before the filters, unless the filters were not in place prior to the fire


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## beach

> we are talking about an exhaust fan that sets outside the buildingand the electric power runs on the outside of the unit
> 
> most fires I have seen are before the filters, unless the filters were not in place prior to the fire


Exactly, CDA and FMWB!


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## peach

well, not here... everything shuts down .. not just me enforcing it that way.


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## Builder Bob

If you really want to understand the issues, travel back into time when " saponification" (spelling?) was what put the fire out - The dry powder from the extinguishing system would mix with the animal fat to create soap ...otherwise known as foam. It did not really matter with the appliances prior to the energy conservation movement along with healthy alternatives to animal fat. Several buildings were burnt to the ground when the cooking medium was changed from animal fat to vegetable oil and the appliances became more energy efficient.( better insulated to retain heat )

 (BTW, in the old days of animal fat, fuel source or electrical power was required to be removed from the cooking equipment - so nothing new.)

The more energy efficient appliances keep the temperature of the vegetable oil above ignition temperature for a long time, thus re-ignition of the new fangled vegetable oil would occur, thus defeating the one-time shot of a hood suppression system.

That is a brief outline why UL-300 systems are required today.....

The basic concepts of how exhaust systems should act are basically unchanged in 25 years of code enforcement ---- the only (new) question is what does the manufacture's installation instruction state?

http://www.nafed.org/resources/library/ul300.cfm


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## peach

well, Bob.. the ICC hasn't kept up with the technology (or should I say, Ansul hasn't lobbied the ICC to make a code change). The IBC is pretty clear.

By the way, I don't see NFPA 96 as a referenced standard in either the IBC or IFC (2006)

My humble opinion


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## Builder Bob

Nfpa 96----

Be sure to read previous post - I never did state that 96 was referenced, only that the testing standard for UL is based upon NFPA 96...... The IMC also states that equipment and appliances shall be installed in accordance with manufacture's specifications...... which means for every hood you are inspecting, you better have that model's installation guide to determine the proper sequence of operations for the hood when the fire suppression system activates.

Just saying..... IMHO the manufacture's guide is going to mirror NFPA 96's requirements in order to get UL or FM certified.


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## peach

The IMC doesn't trump the IBC, Bob


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## beach

1. The IBC states that the suppression system shall shut down the fuel or electrical power supply  to the COOKING EQUIPMENT

2. The CMC states that the exhaust fan(s) shall continue to operate.

3. The manufacturer (Ansul) states that the exhaust fans should be left on(with the approval of UL).

4. An exhaust fan is not COOKING EQUIPMENT.

5. The exhaust fan(s) is located on the roof.

What code change does Ansul need to make????

If someone wants to do it their own way, with their own interpretation, and they consider themselves the AHJ........... by all means, do whatever you want!

I'll stick with common sense, IMHO


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## peach

your state says one thing beach.. not everyone agrees with you.  Let's agree to disagree and let this thread die.

Thanks


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## beach

West Des Moines Fire Department

FIRE PREVENTION BUREAU

TYPE 1 HOODS & SUPPRESSION

WDM Fire Code and IMC 2006

May 14, 2007

1. Type I Hoods shall be installed where cooking appliances produce grease vapors or smoke.

2.  See all applicable provisions pertaining to installations of Type I hoods and grease ducts under the 2006 International Mechanical Code, Section 506, 507 and 508.

3. Sufficient make up air shall be provided to all hoods. Supply air openings shall be a minimum of 6'-0" from any part of a Type I Hood. The supply air unit and /or a fire-smoke damper installed in the supply air opening may be interconnected to the fire extinguishing system to shut down upon activation of the extinguishing system.

 	4. All equipment located under a Type I Hood shall be interconnected with the fire extinguishing system and make-up (supply) air system so that all fuel and energy sources shall be terminated upon activation of the fire extinguishing system.  *The exhaust fan for the Type I Hood shall continue to operate unless fire **extinguishing system requirements state otherwise.*  Supply air within 6-feet of the hood shall shut down upon system activation.

5.	If the building has a fire alarm system, then activation of the hood extinguishing system shall activate the building fire alarm system.

6.	Pull stations to activate the hood suppression system shall be no closer than 10-feet to the hood and no more than 20-feet from the hood (unless approved by the Fire Marshal.  The “K” class extinguisher with signs shall be mounted next to the pull station.

7.	Plans and fees shall be submitted for the hood suppression system by a licensed contractor to the Fire Marshal.

            For mechanical questions call the Mechanical Inspector at 515-222-3630.

	For additional information, please contact the Fire Marshal at 515-222-3420.


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## peach

that's there.. not where either of us are... please drop it.


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## beach

Okayyyyyyyyyyy............


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## Builder Bob

I am aware of that --- how about Chapter 28 of the IBC?


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