Data Center Deluge Activation

[haze10]

For FM200 deluge systems in data centers. Whats the present thought on the activation for the deluge system. Typically it has been two smoke detectors in simultaneous alarm. With the transition to smaller and smaller servers, the size of a desk top computer, should be dump the system because of one power supply smoldering? Not sure if a smoke detector truely represents a fire condition. I am wondering if two heat detectors in simultaneous alarm would not be a better choice to activate the deluge. Smoke detectors can still be used as early warning, but as a supervisory role.

My State does not specifically address data centers. Is there any reference to NFPA or industry guigelines you can provide.

 

[NJ1]

I am bit confused. Is it a FM200 or a deluge system. You can not have both as one system. One is water based and the other is gas

 

[haze10]

I used the word deluge to refer to the dumping action. Right now it is actually a Halon system which we plan to upgrade to FM200.
I find smoke detectors to be sensitive, and while they react well to smoke, they are not indicative of a real fire. A smoldering power supply in one of any ten servers could generate enough smoke to trigger two SD's simultaneously. Maybe that's what you want, but I think it a bit wasteful to dump the whole system on a power supply that might self extinghuish itself anyway. I would prefer to have the smoke detectors generate an alarm, but the heat detectors to actually generate the dump of the system.

 

[LCREP]

Heat detectors to dump a gas suppression system? Really?? why have the gas system anyway? By the time you have enough heat to trip the gas suppression system you have a large fire developing a lot of heat, AND a lot of damage. Even with 135F detectors you are incurring a lot of damage to your equipment. How well will your computer equipment operate to a smoking hot fire and the corrosive smoke that is generates??

The idea is early detection and suppression to prevent a total loss. If you want early notification look at a VESDA system. It samples the air via a pump and piping and has various levels of detection. Have it monitor the return air and you can then know what is going on. Then use the smoke detector to trip the gas suppression system.

Is your facility manned 24/7/365? If not who is going to respond to find out it is only a "small" fire. How mission critical is the data center? Do you have a hot site for the data functions? Can you stand to have your data center down for a few weeks?

Why are you removing the halon system and going with FM 200? Halon works great, a lot of it around, the military stills uses tons of it. If you go with FM 200 you will have to replace all the piping and nozzles. You know they have a drop in replacement for Halon,it is called FE 36, all you will need is to change the nozzles.

****************************************
Fire Sprinklers Save Firefighters’ Lives Too!

 

[rbulsara]

FM200 or gaseous fire suppression generally is not a code requirement for data centers. (Codes vary by states in the USA). If you do choose to have it, however, the standard to review is NFPA 75.

Gaseous fire suppression system is less and less preferred in data centers now a days, for a variety reason. A major one being lack of assurance of (gas) sealing the protected space and testing over time.

Insurance under writers may have a say as to what the client should have. It essentially becomes a economic cost/risk/benefit excercise.



Rafiq Bulsara

http://www.srengineersct.com

 

[rbulsara]

Also safe guards against nuisance discharge are very common and well accepted, such as "cross zoning", double interlocks, detector counting and a few other things like having a pre-alarm and ability to abort, if there is someone around.

All you need a is a good engineer and a good vendor.

Rafiq Bulsara

http://www.srengineersct.com

 

[haze10]

We probably will keep the Halon system for now, but need to have a plan in place should it ever be discharged. Thanks for the FE36 suggestion, I will investigate that.

The facility has a central security system that is 24/7, and they see all alarms on the central panel.

I guess this is a matter of opinion. When I go in the data center there are a few desktop servers on desks and a couple rack of servers. The fire department is 1/3 mile away and respond times are around 6 minutes.

My thought is 'why' dump the halon system over something small that would probably be self extinghuishing, like a power supply.
The room would be fitted with smoke detectors, any one in alarm, would set off the fire alarm and call the fire dept. Two heat detectors, combo 135F/rate of rise, would have to be in alarm to dump the Halon.

My position is that this is the best overall compromise between protection and a false discharge.

Do you really find this outline to be unacceptable? The two smoke detector system has been there since the 1980's and has never discharged, so maybe I am being paranoid.

 

[b1ueshift]

Deluge is used almost exclusively for NFPA 15 type exposure protection systems. I would recommend you use some other word like clean agent, or gaseous suppression.

Using a gas like FM200 it's probably not a good idea to use heat detectors.

FM200 is tested on small fires and it doesn't necessarily work on big fires as the extinguishing agent is consumed during the extinguishing process. I've googled heptane pan fire and it's about 175 kW. If you wait for both heat detectors to go off, then sound the alarm for 30 seconds then discharge the gas, by the time the alarm goes off, you could have a fire in excess of 175kW and it's doubtful that the FM200 will extinguish it.

 

[LCREP]

Haze,

Do you have an insurance carrier?, if so reach out to them BEFORE you do anything. They may have fire protection professionals on staff that can advise you. They may also have minimum requirements for fixed fire proteciton for a data center.

I am on the insurance side of the business and have looked at 1000's of computer rooms and I have NEVER run into a heat detector used to trip a gas suppression system. Not saying they do not exist, I am saying if they do I have run into it.

If your company stated the room is protected by smoke detection system in an insurance application for coverage, and you change that without asking, what fun if you have a claim! OR depending on the $$$ at risk and the associated business interuprion loss potential, they could ask to be removed from the account, increase the deductible in case of a loss etc.

Bottom line let who ever handles your insurance know what you plan to do and get the insurance carrier, in writing, to sign off.

****************************************
Fire Sprinklers Save Firefighters’ Lives Too!

 

[cdafd]

Agree with lcrep

Keep the two smokes or one smoke and one air sampling

Two heats you will have a nice fire going

You should look into upgrading the fire alarm system

They have advanced over the years, so nuisance alarms are cut back drastically

You also have the abort switch yo hold till the fire dept gets there

 

[DavidCR]

If you fall in the scope of NFPA 75/76 this standard is very specific on defining the type of fire detection needed for clean agent system activation.

There are definitions of "early" and "very early" fire detection that must be considered if you have to go by the rule. If you go that way, you have to look after VESDA systems or equivalents as mentioned.

But in general you better go with care dealing with the activation of a gas system, there are other aspects that are important, type of enclosure, design concentration, enclosure conditions, etc.

Out of the code, my opinion is that there are some spot type smoke detectors that have low sensitivity that would be an early detection that used on crossed zone can give a reasonable degree of confidence to prevent false alarms and accidental gas discharges.

Thinking of the Halon retrofit, there is the HFC125(Ecaro-25) that in some conditions can use the same pipes of the Halon as an easy retrofit.