subject: Fire Suppression Systems in an Increasingly Electronic Environment [print this page] Fire Suppression Systems in an Increasingly Electronic Environment
The combination of telecommunications and computer technology development in the past few decades and the ever-growing importance of the Internet, have transformed private and public administration. One result has been to transform also the nature of fire risk and how we deal with it. We now have concentrations of critical systems in ever smaller spaces, characterised by the presence of electricity and heat. So the danger of fire is omnipresent, with potential knock-on consequences that extend far beyond the simple destruction of equipment or property. Yet all such data centres and control rooms are fundamentally based on two of the elements most incompatible with traditional fire fighting techniques: electricity and electronics. Whether for a relatively simple installation like a building management system server or for a giant data centre the size of a football stadium, designing an appropriate fire suppression system is fundamental to modern fire safety engineering. All of them work by the rapid introduction of something inimical to flame and combustion, from water and watermist to aerosols and foams, dry chemicals and gaseous extinguishing agents. In such automatic extinguishing systems, the choice of the appropriate or most effective method in any particular circumstance depends in the first instance on the presence of people in the fire area. Clearly, many of the materials that could be used are themselves hazardous to human health, either directly or by oxygen depletion. While there are still areas of business or other activity where traditional water sprinkler systems are appropriate and adequate, gaseous suppression has for decades been the default choice for automated systems. Where there are valuable systems and equipment that would be damaged or destroyed by liquid, there is little option but to utilise one of the wide range of gas fire suppression solutions on the market. The over-riding factor to be considered is whether the space is regularly occupied by people or at risk of somebody being present at the moment of combustion-or even inadvertently after a fire has begun. Other significant elements in planning an automatic system based on the characteristics of the space include the choice between total flooding with the fire suppression gas or local application designed to deal directly and immediately with the objects, substances or areas of risk within a larger space. Clearly, the total volume and degree of enclosure of the space to be protected will dominate the engineering of the appropriate fire suppression solution. At a more sophisticated level, solutions may incorporate the automated creation of enclosed space by the closure of fire doors, ventilation inlets or other sources of air/oxygen supply so that the gaseous fire suppression can be effective. The optimum performance of the automatic fire suppression system depends on the gas containers being full and under the correct pressure at the time of triggering. For that reason it is important that gas leak detection be a part of the system to complement periodic manual testing of pressure or container weight to ensure that at least the minimum load level of gas is present to ensure there is no malfunction in an emergency. In all cases, an appropriate and effective regime of monitoring and gas leak detection is very likely to have implications for the relevant corporate insurance. Increasingly, such systems are mandated by insurance companies as a condition of cover. The other major area of concern regarding fire suppression gases is that some of the most effective agents are categorised as ozone-depleting threats to the environment. Halon 1301, for example, was in widespread use until the mid-1990s as a highly effective fire suppression agent that did not cause residual damage to equipment such as telecommunications and computers. But Halon production has generally been internationally prohibited since the Montreal Protocol of 1987, notably by the US Lean Air Act of 1994. In most industrial applications, such as refrigeration and air conditioning, it has been replaced in large part by HFCs (hydrofluorocarbons). In fact, almost all fire suppression gases are regulated and leakage inspection or monitoring systems are mandatory.
