Consulting-Specifying Engineer - September 2007 - (Page 9)

Letters staff EDITORIAL STAFF MICHAEL G. IVANOVICH, Editor-in-Chief michael.ivanovich@reedbusiness.com SCOTT SIDDENS, Senior Editor ssiddens@reedbusiness.com AMARA ROZGUS, Senior Editor & Manager of E-Content amara.rozgus@reedbusiness.com MELISSA HILLEBRAND, Associate Editor melissa.hillebrand@reedbusiness.com PATRICK LYNCH, Editorial lntern patrick.lynch@reedbusiness.com DIRK CHRISTENSEN, Website Specialist MYLES ADAMSON, Art Director BARBARA HORWITZ-BENNETT, Contributing Editor CONSULTING EDITORS ANIL AHUJA, P.E., LEED AP, RCDD, CCJM Engineers, Chicago PAT BANSE, P.E., Senior Mechanical Engineer Smith Seckman Reid Inc., Houston ALFRED R. BORDEN IV, IALD, The Lighting Practice, Philadelphia DAVID COOPER, P.E., C.E.M., Executive Vice President Flack + Kurtz, New York RAJ P. GUPTA, P.E., President Environmental Systems Design, Inc., Chicago KEITH LANE, P.E., RCDD, LC, LEED AP, Partner/Principal Lane Coburn & Assocs., Seattle KENNETH L. LOVORN, P.E., President Lovorn Engineering Assocs., Pittsburgh JOHN MAGLIANO, P.E., Syska Hennessy Group, New York SYED PEERAN, P.E., Ph.D., Senior Engineer Camp Dresser & McKee, Inc., Cambridge, Mass. JOHN M. RATTENBURY, P.E., LEED AP, V.P. of Engineering Rainwater Management Solutions, Salem, Va. MARTIN H. REISS, P.E., The RJA Group, Inc., Framingham, Mass. ALAN TRAUGOTT, Principal, CJL Engineering, Moon Township, Pa. PETER D. ZAK, P.E., Principal Graef, Anhalt, Schloemer & Assocs., Inc., Milwaukee PUBLICATION SERVICES JIM LANGHENRY, Publisher 630-288-8789 jlanghenry@reedbusiness.com TRUDY KELLY, Assistant to the Publisher ELENA MOELLER-YOUNGER, Marketing Director ALLISON TERNES, Audience Marketing Director ELETTA HARRIS, Production Manager FELECIA STEPHENS, Advertising Services Consulting-Specifying Engineer’s editorial offices are located at 2000 Clearwater Dr., Oak Brook, IL 60523. Phone (630) 288-8000. For subscription information, call (303) 470-4445 or go to: getFREEmag.com/cse. For reprints, call (800) 290-5460 x100 or e-mail CSE@reprintbuyer.com. REED BUSINESS INFORMATION Founded in 1933 Tad Smith, Chief Executive Officer Jeff Greisch, President, Chicago Division READER FEEDBACK Data center fire protection I just read your article entitled “Data Center Technology Past, Present and Future” (CSE 07/07, p. 38). Very interesting. I am a fire protection engineer with more than 30 years of experience in the field. I hope that I am up-to-date on extinguishing agents. As such, I would like to comment on a paragraph found in your informative article. The paragraph (p. 39) reads: “Data centers often employ a common supplemental fire protection system—a clean agent—that releases a gaseous substance that captures the oxygen from the room, and therefore, extinguishes the fire. The gas then turns into a powder, leaving a dust residue behind that is easy to clean up and doesn’t damage the equipment.” I believe the above paragraph contains errors. There are several clean agents on the market today. All work in one of three ways. Some use two of the methods: 1. Inert gases that displace the air (oxygen) dropping the concentration, such that a fire cannot burn. 2. Agents that absorb the heat of combustion, thus cooling a fire below a self-sustaining temperature. 3. Agents that break the chemical chain reaction involved in combustion. None “captures the oxygen from the room.” I do not know of any oxygen-scavenger agents. Second to be a “clean agent,” there cannot be any residue at all. The inert gases (argon, nitrogen, CO2) are just that. None of these leave a residue or turn to a powder. The other agents are gases or a volatile liquid that vaporizes quickly and completely. I have not heard of any of them leaving a residue. One agent is rather “oily” as a liquid but it does vaporize completely. I personally have not worked with this agent, so it may leave a film of some kind. I also would like to take issue with the statement in a statement in an earlier paragraph (p. 39) about “leaking sprinkler heads.” Sprinklers are highly reliable, thoroughly pressure-tested and have an exceedingly low leak rate. They just do not leak enough to be of a concern in a data center. While what the author says about sprinklers operating at 165°F is true—only the sprinkler in the vicinity of the fire will operate. Sprinklers operate independently and only when they (an individual head) reaches 165°F. To obtain a ceiling temperature of 165°F takes a rather large fire. The operators have to be sound Consulting-Specifying Engineer • SEPTEMBER, 2007 9 http://getFREEmag.com/cse

Table of Contents Feed for the Digital Edition of Consulting-Specifying Engineer - September 2007

Contents M/E Roundtable Cover Story: Airborne Superbugs Third-Party Liability Back to School Product Spotlight Codes & Standards Professional Practices How To New Products Jobs/Cliassifieds Specifier’s Notebook Pure Power Supplement New Technologies, Same Old Transmission Problems Wireless Battery Recharging Solar Concentration Renewables Tracking System A Mighty Wind The Importance of Load Bank Testing Quality Power for Security Systems

Consulting-Specifying Engineer - September 2007

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