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CO2 For Computers by John Dunham As I make contacts with my customers, the fire equipment distributors in the eight states I cover as a regional sales management, I hear many "opinions" voices on proper fire protection, or at least, an individual interpretation of what is "proper." I also get the view and opinions of the correct and proper method of protection from industry authorities. Of course, being a professional salesperson, I try to agree with all expert opinions and sell what those experts find acceptable. Sometimes I walk away after receiving an order and hit the "books." The "books" I refer to are NFPA standards for a product or system, and the Underwriters Laboratories (UL) book of current fire equipment products. As most fire officials and distributors use NFPA standard as a guide and insist on a product listed by UL or Factory Mutual, I am, on occasion, amazed at some of the industry's interpretations! For example, recently the use of CO2 portable extinguishers to replace Halon 1211 portables for use around computers and office equipment has me hitting the "books." I don't intend to debate the pro's and con's of halon use, I just find that the customers of the fire extinguisher distributors are looking for alternatives to halon, and for the use on and around computers CO2 is the agent of choice. I have been as surprised as you when industry authorities have stated that dry chemical was the best agent for computers! At some point in the past, maybe twenty years ago, it may have been acceptable to sell halon against CO2 by using a term that instilled fear in the owner of a computer or any other equipment that might heat up when in use. This term was "thermal shock." I have encountered industry authorities that swear that "you can't use CO2 on a computer because of 'thermal shock'." They also state that CO2 will ruin a computer because of water, "snow", condensation or some other mysterious form of moisture derived from the gas. I haven't stood face to face with a fire official and told him he was wrong, but I can't find any evidence that CO2 is harmful to computers or any other office equipment. I have the impression that I am not the only one who feels this way, but I haven't found anyone who wants to speak up. What follow are my observations, answers to questions I have asked various experts in their fields, excerpts from NFPA publications and information from publications produced by NAFED that may help you understand my feelings about CO2. Power companies, municipalities and industrial firms operating cogeneration turbines are successfully using CO2 for fire suppression. Imagine this -- a multi-million dollar generating unit, turbine engine powered, with all of those close tolerance parts, spinning at high speed and being very hot. A lubrication line rupture, sprays oil and ignites! The CO2 system is activated and hundreds of pounds engulf the complete turbine. The fire is suppressed and CO2 flooding continues under timed release while the turbine winds down. If ever there was to be "thermal shock" it would certainly present itself here. The manufacturers and owners of such expensive, precision equipment which by design runs "hot" have stated that when CO2 contacts a hot surface it forms a gaseous "envelope" and actually insulates the object, allowing it to give off heat slowly while suppressing volatile conditions. Back to computers....NFPA 75, the Standard for the Protection of Electronic Computer/Data Processing Equipment, 1992 Edition, cites the following:
NFPA goes on to state that power should be turned off and you should not try to energize any wet equipment. Compressed air, aerosol sprays and portable hair dryers may be used to dry the wet equipment. Allianz Risk Service published the results of a special study it conducted titled, "Fire Extinguishing Tests on Computer Equipment" on fully functioning computers and disk storage units. The testing that is of interest here was conducted as "Extinguishing by Halon 1211 fire extinguisher" and "Extinguishing by CO2 fire extinguisher." In the Allianz publication "Cold Tests of Fully Functioned Computer," the following information is pertinent: "A second series of cold tests was carried out on a fully functioned computer and no fire was ignited. The intention was to investigate whether the functioning of the computer system is adversely affected by the introduction of the extinguishing agent. During the tests, the temperature in the computers was measured at 23 points, the concentration of extinguishing agent at eight points and the relative humidity at two points. "The tests for which little adverse effect on function was expected were performed first; the tests for which severe 'cold shocks' might be expected were place at the end of the test series. The extinguishing agents Halon 1301, Halon 1211, and CO2 were used. Tests were carried out with the computer equipment both switched off and on. The test series concluded with the use of portable fire extinguishers with Halon 1211 and CO2. In these tests, the extinguishing agent was aimed directly at the individual components. "The most important information derived form this series of tests was that the functional capability of the computers was not affected by extinguishing agents." "Introducing extinguishing agents into an operating computer produced no negative effects on the functional capability of the equipment. Even when CO2 was used in a live unit, there was still no adverse effect on its function. The same applies to CO2 flooding in a disk storage unit with the writing/reading heads driven into position." When individual subassemblies were sprayed with the portable fire extinguishers, there was not disturbance to the computers, even though icing on the sub-assembly frames was present. NAFED was compiled and distributed a booklet called "Checklist for Fire Extinguisher Applications." "The booklet is designed to help select the most suitable and acceptable type(s) for hazards." For equipment such as "Data Processing, Delicate Electronics, Photocopiers and Telecommunications" recommended extinguishing agents are: Carbon Dioxide, Halon 1211 or possible System Need. In conclusion, with the availability of the documentation and recommendations that I can find, I can only suggest that it is okay to provide CO2 portables for use in computer and office equipment environments. Please note that for ordinary combustible materials, Class A fires, you will need to provide pressurized water or other approved extinguishers. Reprinted from Firewatch!  |
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