Ways to protect data centers from fire
October 5, 2012
Today’s tip is to make sure your data center is adequately protected from fire. In the past, of course, data centers could use Halon to put out an electrical fire. But, once it became known that Halon was destroying the ozone layer, it was phased out for new systems.
Halon alternatives generally fall into two categories: clean agent systems, many of which use halocarbons, and inert gases. Clean agent systems extinguish fires by removing heat. Inert gases essentially suffocate the fire by depriving it of oxygen. Both can be "excellent, reliable systems," if they are properly designed and commissioned, says Scott Golly, senior fire protection engineer at Hughes Associates. Inert gas systems use a higher concentration of gas to extinguish a fire than halocarbon systems, so they require more storage space.
Any facility using a "dry," gaseous product for fire suppression must also have a water-suppression system, according to Kevin J. McCarthy, vice president of engineering company EDG2. But using water in a data center "can cause catastrophic damage to equipment," Golly says.
The sensitivity of conventional sprinklers may justify a pre-action sprinkler system, which requires multiple events for pipes to flood with water. A pre-action sprinkler has a large valve at the back of the water supply, so the pipes are empty.
A double interact system uses a clean agent to put out a fire long before a smoke-head is set off. A pre-action system may also require the activation of two smoke detectors in two different zones before a deluge valve opens to fill the pipes. The clean agent or inert gas fire suppression is designed to put out the fire before the sprinkler head begins dropping water.
Facility managers must evaluate what would constitute an acceptable loss. "Can you afford to have all those computers taken off line for several weeks?" Golly says. "If you cannot, then you cannot rely solely on sprinklers." Other questions to consider include storage space and cost. Both clean agent and inert gas systems are more expensive than pre-action systems.