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Posted By: BigB Ansul Fire Supression - 04/10/12 04:59 AM
This may be more of an NFPA question but here goes. A rehab facility has an Ansul fire supression system in the kitchen exhaust hood. When the system activates, normal electrical power to the kitchen is automatically cut off. This includes power to the exhaust hood. The rep from the fire supression company says the exhaust hood should be wired to the emergency backup panel so that it will continue to exhaust smoke during a fire.

Is he correct, or would this create a violation?
Posted By: gfretwell Re: Ansul Fire Supression - 04/10/12 07:07 AM
517.34(A)(5) allows it. I would ask your fire official if he requires it.
Quote

517.34 Equipment System Connection to Alternate Power Source.

(A) Equipment for Delayed Automatic Connection. The following equipment shall be permitted to be arranged for delayed automatic connection to the alternate power source:

(5) Kitchen hood supply or exhaust systems, or both, if required to operate during a fire in or under the hood.


There is the same language in 517.43(A)(4)
(Health Care Facilities)
Posted By: ampherder Re: Ansul Fire Supression - 04/10/12 02:52 PM
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.

Posted By: HotLine1 Re: Ansul Fire Supression - 04/11/12 01:10 AM
Ampherder:

Thank you for the code article. This is a 'difficult' item for some to grasp.

Supply (Make-up air) is a shut down, exhaust is operating when supression system is activated. That is the 'norm' here. I have not seen any where the MUA is 'on' during a fire supression activation.
Posted By: renosteinke Re: Ansul Fire Supression - 04/11/12 02:19 AM
HOWEVER ....

A careful reading of NFPA 96 is quite clear on two commonly misrepresented points.

First, "make up air" is specifically described as air supplied specifically to the hood, from within the hood assembly. NFPA 96 does NOT call for shutting down the general air supply to the kitchen, or shutting down the general air conditioning. Doing so is not forbidden - but it's not required.

Second, NFPA 96 is quite blunt that the exhaust fan need not operate if the cooking units and hood are "off." The fan need operate only when the equipment is operating.

hem and haw and engineer all you want, but your 'design ideas' may not be what the code actually calls for.
Posted By: Yoopersup Re: Ansul Fire Supression - 04/11/12 03:08 AM
It was always Explained to me is that the MAU must shut down so it does not feed fresh air to the Fire , But Exhaust maintains running because of the Grease up in the exhaust Duct well get The fire stopping chemical.
Posted By: HotLine1 Re: Ansul Fire Supression - 04/11/12 03:34 AM
Reno:

My intent was and is MUA, which is dedicated to the hood, not any climate control HVAC unit.

As Yoop said; cooking appliances operating, exhaust & MUA "ON", supression system activated, MUA "OFF"; EXHAUST "ON".

That is how it has been, and is; I'll kick this around with my Fire Official, time permitting.

Posted By: gfretwell Re: Ansul Fire Supression - 04/11/12 06:31 AM
I really only did a few hoods and they all had to be signed off by the fire marshal. Him and the Ansul guys worked out the details and I just inspected the workmanship and materials.
Posted By: renosteinke Re: Ansul Fire Supression - 04/11/12 01:18 PM
HotLine, I have no problem with your description.

The problems arise when there is no fresh air piped directly to the hood. I routinely see the 'hood guys' hanging their tissues on every air supply in sight, expecting them to be shut down. In some instances the kitchen is connected to the dining area with a pass-through, bar-like opening, and the fresh air comes from that other room. I wanted to stress that the only make up air that is required to be shut down is the air supplied directly to the hood, and not these indirect supplies.

Likewise, I have witnessed tests where the hood guys expected the exhaust fan to start up when they tripped the unit, even when everything was shut down. Again, NFPA 96 specifically explains that this is not required.

I suppose I ought to add two other 'refinements,' details that apply only in some cases:
1) If there is no alarm system, you need to mount some manner of alarm (bell, strobe, etc.) that will sound off if the unit trips; and,
2) If the cooking equipment uses 'old fashioned' pilot lights, you need a gas shut-off that has to be manually reset, rather than one that automatically resets when you reset the unit.

I've done these hoods in a few different jurisdictions, alongside several different hood guys, and ... this is the part that annoys me ... I have yet to encounter either a hood guy or a fire marshal who has ever actually held NFPA 96 in their hands. They know 'all about' the requirements, but have never read them. Ah, the look of wonder and amazement when I produce my copy ...

The other thing that annoys me is when I hear 'it's a pre-packaged unit, all you need to do is bring power to it.' Yea, right. Invariably I end up doing a lot more than just that.

A final note: At least once I've encountered a hood guy who did not want to pass inspection. No, his 'game' involved charging for each visit .... so, if he could give me non-functioning equipment and incomplete/erroneous instructions that would allow him to charge for another test, all the better! All I can say is that he picked the wrong guy to annoy.
Posted By: HotLine1 Re: Ansul Fire Supression - 04/12/12 12:53 AM
Reno:

Just an FYI on this subject. About 10 days ago, a resturant renovation inspection, I was checking the hood. I noticed that there were 'registers' (HVAC vents) cut into the front face of the hood, and they had little 'streamers' to indicate air-flow. For a few minutes, I thought 'HVAC' for the kitchen. I asked that the exhaust fan be 'on' & he flipped a switch. I said 'turn on MUA, he walked out of site. Came back & said 'it's on'. I said 'turn it off', he walked away, the air stopped. Ah, so did the 'registers'.

I said, where is the switch.....he walked over to the HVAC T'stat!!! They tapped the HVAC duct for the MUA!

There was a severe language issue; my Cantoneese is very limited!

Red sticker, there was a lot of issues in addition to the above.
Posted By: renosteinke Re: Ansul Fire Supression - 04/12/12 03:11 AM
Well, I'll give you points for being observant and thorough!

I think ... (siren sounds, and a robot voice warns 'Danger! Will Robinson! Danger!) ... the ignorance and confusion on the hood issue is quite deliberate.

Look at who sells the systems: the same folks who do sprinkler systems. In both instances, the manufacturers have done their utmost to force customers to use not only their complete systems, but also their design services. They went so far as to 'obsolete' a perfectly fine extinguishing agent in favor of a new one that, amazingly, requires a new system be installed.

These protected sales arrangements make it easy to pass off details of your system as 'code requirements,' when such is not the case. Far too often, the 'expertise' of the installer is limited to just one brand and model of equipment.

I have something of a unique insight into this topic; my first 'real' job was testing various fire and alarm related products for a testing lab. As such, I read an awful lot of the standards, test procedures, and understand the way the system works. There have been a few times where I've had to point out to various 'experts' that the very data and materials they're misunderstanding originated with .... ME! Or, at least, I was there when the data was generated.

On the electrical forums, we may fuss and cuss over code issues- but the other codes seem to get a free pass. I'm really disappointed at some of the ignorance I've seen among "experts."
Posted By: Scott35 Re: Ansul Fire Supression - 04/12/12 03:42 AM
It would be great to get a copy of NFPA 96! Is there a PDF Download available from the folks on Batterymarch Park?

Back in "the day" circa 1980's - late 1990's; when I used to actually work...,
the Ventilation sub assembly to be shut down / not shut down on detection of Combustion were - at best, decided by some sort of Daily Lottery; possibly per the roll of Dice...

Conflicting requests / specifications between the MEP Teams -vs- the Officials of a given Agency, resulted in tremendous ExcedrinŽ Headaches for all involved.

For Hoods, sometimes the MUA was shut down and the EF stayed on; other times the EF was shut down and the MUA stayed on.
Sometimes both MUA and EF were shut down, and other times both stayed on!
There were a few occasions where no one actually cared what the shut down sequence was!
Still get woozy thinking about those installs!

Per the Electrical Designs & Engineering of Refrigeration related Systems; where Flammable, Toxic or Highly Toxic Refrigerants (i.e.: NH3 {Ammonia Systems}) are involved, I have a 10 Page document which Specifies the basic requirements and regulations per the CFC (California Fire Code - CCR Title 24, Part 9).
Very minimal Data, but its something.

A somewhat related issue existed back then - and has reared its ugly head again recently... Placement of Duct Smoke Detectors in Plenums for HVAC Package Units.

Conflicts pertaining to which Duct should be monitored - Supply Air or Return Air - spawned some rather interesting Designs & Addenda!

There have been many instances, where only the Supply Air Plenums were specified to be monitored.
Even after initiating RFI Blitzkriegs, the "Commands" were to monitor Supply Air Plenums only.

(BTW, the Duct Smokes were installed no farther than 60" from the Package Unit, and - of course - had the typical 1/2" EMT Monitoring Tube running through the center of the Duct, perpendicular to the Air flow)

It makes sense (at least to me) to monitor the Return Air Plenums for Combustion (Smoke), not the Supply Air Plenums themselves.
Economizers and OA Fans bring Unconditioned Outside Air in to the Package Unit / Supply Air.
The minimum PPM required to trigger an Alarm Status will be offset by the "Thinned Out Smoke" in the Supply Plenums.

Having both monitored makes sense too. This covers both Supply and Return Air and also monitors the Package Unit for catastrophic failure.

Open for comments.

-- Scott (EE)
Posted By: BigB Re: Ansul Fire Supression - 04/12/12 05:21 AM
Thanks you guys! Now I can walk in there knowing what I'm talking about. smile
Posted By: renosteinke Re: Ansul Fire Supression - 04/12/12 08:38 PM
Yes, you can purchase NFPA 96 from ... guess who? ... the NFPA and download it. The download IS limited, so I suggest the first thing you do is print yourself a copy. (I think it's about 30 pages long- and the parts we are concerned with are on only one or two of those pages).

The price, if I recall correctly, was about $30.

Posted By: HotLine1 Re: Ansul Fire Supression - 04/13/12 01:16 AM
Scott:
I agree that monitoring both would be ideal. That said, I'm happy that I (Electrical AHJ) do not have to get into this. It's the Fire Subcode AHJs responsibility.

As to the kitchen hoods, I stand on what I posted above. Another interesting job in plan review is a prototype lith ion battery (or something similar/newer) with a few chemical hoods and supression. That has to wait until I get back from a vacation next week! (Along with a lot of others) Going to Arizona & Vegas!!
Posted By: leland Re: Ansul Fire Supression - 04/14/12 07:42 AM
NFPA 96, in regards to Kitchen systems 10.2.6 refers you to NFPA 17A wet chemical systems.

17A states that exhaust fans and dampers need not shut down, as the systems have been tested for zero and high velocity flow conditions.

I can not find MAU shut down in 17A. the closest would be "all fuel sources.." must shut down.

In 96- 8.3.2 it shall shut down on activation of system.

I would see (NFPA 96) chap 8 and 10 as 2 independent directives.
chap-8 says to shut down MUA.
chap 10- refers us to NFPA 17A and MFGRS instructions.
Posted By: leland Re: Ansul Fire Supression - 04/20/12 07:51 AM
Originally Posted by renosteinke
Well, I'll give you points for being observant and thorough!

I think ... (siren sounds, and a robot voice warns 'Danger! Will Robinson! Danger!) ... the ignorance and confusion on the hood issue is quite deliberate.

[color:#FF0000]#3) Look at who sells the systems: the same folks who do sprinkler systems.[/color] [color:#FF0000]#1)In both instances, the manufacturers have done their utmost to force customers to use not only their complete systems, but also their design services. [color:#FF0000]#1A) They went so far as to 'obsolete' a perfectly fine extinguishing agent in favor of a new one that, amazingly, requires a new system be installed.[/color][/color]

[color:#FF0000]#2) These protected sales arrangements make it easy to pass off details of your system as 'code requirements,' when such is not the case. Far too often, the 'expertise' of the installer is limited to just one brand and model of equipment.[/color]

[color:#FF0000] #4)I have something of a unique insight into this topic; my first 'real' job was testing various fire and alarm related products for a testing lab. As such, I read an awful lot of the standards, test procedures, and understand the way the system works. There have been a few times where I've had to point out to various 'experts' that the very data and materials they're misunderstanding originated with ....[/color] ME! Or, at least, I was there when the data was generated.

[color:#FF0000]#5) On the electrical forums, we may fuss and cuss over code issues- but the other codes seem to get a free pass. I'm really disappointed at some of the ignorance I've seen among "experts."
[/color]


#1) The main reason for this change, was the change in the cooking process.

The industry has changed from animal fat to vegetable oil.
The appliances have also changed.
Due this fact of ingredient/product change, changes needed to be made.

And they were. For the better.

vegetable oil cooks at a much higher temperature, having a greater high auto-ignition potential, and the newer appliances respond to that,. IE: run hotter.

Therefore the change in the chemical was needed.
This was instituted thru testing and real life issues.

Remember the 'Old days'? When CO2 systems were covering the kitchen hoods? Essentially useless.

Back to the "entire system upgrade', this is needed again due the new chemical.
New flow rates and angles of nozzles are important.

This agent works as a foam- covers and smothers.
looks like a moraine covering, and is easily cleaned up with water.

Additionally, we are trained, certified, tested by the State fire Marshall, and re-certified every two(2) years.Distributors of most major suppression MFGRs.

#2) This was instituted by ANSI and UL, No doubt manufactures had some influence, But that is different than the NEC, How?

#3) I find that hard to believe. Sprinkler guys/co. won't touch this stuff.
(personally, I find this comment..... UN-flattering.. Coz I am one. (Did 4 yrs of school and my on job training.(licensed sprinkler fitter) frown )

#4) Nice, I would love to get some more insight on the inner workings of the industry.

#5) Full circle. Funny how life is.

one industry (related) is influenced by manufactures. AFCI ring a bell? Not to mention other electrical code issues. Of course MFGRS have influence.
NFPA- in this end,is only a start. Local AHJ has a big say. To think that MFGRs have no influence, Or the People in the industry are.. Numb. perhaps you have only met the 'Grunts'. All industries have them.
How many 'Licensed' electricians do you know that can only 'plug and switch'? I know many.

PEACE! Thank you for your time. Lee.
Posted By: renosteinke Re: Ansul Fire Supression - 04/20/12 07:00 PM
Thanks for the reply.

As for the 'unflattering remark' ... well, I should have aimed my barb a bit better. I was referring to the manufacturers of the equipment, not the installers. I am aware that different unions are at work here...

Higher temps? Auto ignition? CO2?

I'm actually more familiar with the older Halon and dry chemical systems as installed ... CO2 seems to have fallen from favor, though the systems are still made and installed.

I'm all in favor of inventing better products; I disagree with the marketing decision that denies folks the parts needed to maintain an existing system.

OK, with Halon we had the EPA act ... but there was no governmental action behind the switch to the "K" system.

A foam, eh? Interesting. The use of foam is nothing new, and I wonder how the "K" stuff differs from AFFF.

The fire test for "B" type agents (foams, dry chemmical, etc.) involved putting out a flaming pan of heptane (similar in weight to gasoline). That's pretty hot, and the stuff ignites pretty easily. That there is a new rathing, "K", suggests to me that there is a different test. I'd be interested in learning about that test.
Posted By: leland Re: Ansul Fire Supression - 04/21/12 01:16 AM
For some that may not be familiar with The kitchen (NFPA 17A) systems, this is a good overall of basic operation.
It is an Ansul system, but there are several MFGs of this type system. personally I like the Ansul set up and is tech friendly.

http://www.youtube.com/watch?v=pSMbboZnSL0&feature=related

Check out some of the other type systems also. Pretty cool.
I do all of these systems, a little more interesting than just ol' life safety.
This is the stuff that pays my Ex and my mortgage.
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