Always good to hear from Stewart. I like to hear the BBC and Canadian news for much the same reason--an opinion from somewhere else. Of course Stewart is one of us so....:-} But I'm in total agreement with the sprinkler issue. If the sprinkler system is discharging you are already having a property loss (unless some moron has smacked a head or you just unluckily got one of those 1 in 13M that fail--recently failure to activate seems to be a bigger problem than unwanted activation) due to the fire (and the preceeding smoke). Now would you really prefer a delayed response (how many hours, days, weeks in Sudan Stewart?) followed by responders with hose lines or an early response from low density (comparatively) sprinklers? Another question is how vital is the equipment? I believe that this fear of water in computer rooms is a leftover from the days of multi--million dollar mainframes doing a job that several thousand dollar servers do today. Is this scenario worth the cost and maintenance hassles of gas systems and pre-action? (And as an aside why is there a tendency to use double interlock pre-actions, developed for freezer warehouse applications, in computer rooms, instead of single interlock?) Once upon a time the on-site hardware was the only available storeroom for the electronic data and so a fire destroyed really expensive equipment, interrupted operations and destroyed your history. With cheap (relatively) hardware and cheap (cheap) off-site storage the only real hazard associated with a fire is business interruption which you'll have anyway regardless of suppression means employed. If I had really critical computer stuff I'd separate the UPS from the control/operators, then separate the servers from all that and from the Liebert and then if necessary (due to replacement cost and/or interuption time) break up the server units into discrete groups each of which would be easily replacable and then provide remote back-up electronic storage and then a tape storage back-up, both remote from all other equipment. I'd compartmentalize all these and use wet sprinklers to protect the compartments (building and people) and expect to sacrifice the small amounts of equipment in each, which indeed would be the likely result, at least in part, of a fire anyways. I bet I can build a lot of walls for the cost of even a small wonder gas system.
On 8/23/07, Stewart Kidd <[EMAIL PROTECTED]> wrote: > > CO2 is often preferred in the developing world because it is > universally available - the installation cost may not actually be the > defining factor as the cost and difficulty of gettting a recharge can > outweigh other benefits. I saw an u/s chemical gas system in the > Sudan a couple of months ago, it had ben like that for a year as > there was a problem getting a recharge through customs. If life > safety is an issue (ie if the space is regularly occupied) then agent > of choice is either an inert but life safe gas like Inergen or a > chemical gas like FM200 . Some jurisdictions and insurers do not > favour FM200 . Don't forget there are pending amendments to NFPA 2001 > which will affect things like overpressure flaps. > > New agent Noveon looks tasty but has limited availability in many > places and I have seen prices which look out of line with competing > products. > > But the real question is: What's wrong with sprinklers or mist ? I > specify these all the time for IT and comms rooms. > > Stewart > > Stewart Kidd > Loss Prevention Consultancy > Cambridge, England > > > >Reza, No I minute is OK. BUT be careful of over pressurization due > >to the high rate and high > >concentration. The intent was to allow designers some latitude when > >using very high concentrations > >thus minimizing pipe sizes and preventing over pressurization the > >room and popping windows and such. > >See venting consideration and calcs in 5.6 > > > >Most computer rooms are protected under the "Dry electrical Hazard" > >as you have done. I believe that > >you may take advantage of the extended discharge time if you wish or need to. > > > >Now the big question! Why CO2 when other clean agents are safer, > >cheaper and arguably the industry > >standard? > > > > > >Burton Ford > >SET, CFPS > >Member AFAA > >[EMAIL PROTECTED] > >267-487-1000 > >Fax 267-487-1010 > > > >This e-mail transmission contains information that is intended to be > >confidential and privileged. If > >you receive this e-mail and you are not a named addressee you are > >hereby notified that you are not > >authorized to read, print, retain, copy or disseminate this > >communication without the consent of the > >sender and that doing so is prohibited and may be unlawful. Please > >reply to the message immediately > >by informing the sender that the message was misdirected. After > >replying, please delete and otherwise > >erase it and any attachments from your computer system. Your > >assistance in correcting this error is > >appreciated. Thank you. Cintas Corporation > > > > -----Original Message----- > >From: [EMAIL PROTECTED] > >[mailto:[EMAIL PROTECTED] On > >Behalf Of Reza Esmaeili > >Sent: Thursday, August 23, 2007 10:19 AM > >To: [email protected] > >Subject: Carbon Dioxide System Discharge Time > > > >Hi all, > > For designing a total flooding high pressure carbon dioxide system > >in a 3,500 cubic feet computer > >room with electrical equipment and cable runs, I have specified my > >room as "Dry electrical hazard" > >with flooding factor of 0.083 lb/cubic.feet and 50% design > >concentration according to NFPA-12. > > My questions are as below: > > 1)- Is a computer room fire a deep seated fire? > > 2)- NFPA 12 states that "For deep-seated fires, the design > >concentration shall be achieved within 7 > >minutes, but the rate shall be not less than that required to > >develop a concentration of 30 percent in > >2 minutes." Is it a problem if the total discharge time would be > >only 1 minute for this case? > > Many thanks for your help in advance. > > Reza > > > > > >--------------------------------- > >Pinpoint customers who are looking for what you sell. > >_______________________________________________ > >Sprinklerforum mailing list > >[email protected] > >http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum > > > >To Unsubscribe, send an email to:[EMAIL PROTECTED] > >(Put the word unsubscribe in the subject field) > > > > > > > >This e-mail transmission contains information that is intended to be > >confidential and privileged. If you receive this e-mail and you are > >not a named addressee you are hereby notified that you are not > >authorized to read, print, retain, copy or disseminate this > >communication without the consent of the sender and that doing so is > >prohibited and may be unlawful. Please reply to the message > >immediately by informing the sender that the message was > >misdirected. After replying, please delete and otherwise erase it > >and any attachments from your computer system. Your assistance in > >correcting this error is appreciated. > >_______________________________________________ > >Sprinklerforum mailing list > >[email protected] > >http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum > > > >To Unsubscribe, send an email to:[EMAIL PROTECTED] > >(Put the word unsubscribe in the subject field) > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum > > To Unsubscribe, send an email to:[EMAIL PROTECTED] > (Put the word unsubscribe in the subject field) > -- Ron Greenman at home.... _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum To Unsubscribe, send an email to:[EMAIL PROTECTED] (Put the word unsubscribe in the subject field)
