4 FM quick reads on Data center
1. Experts Conclude Data Centers Can Be Warmer
Today's tip is to consider a warmer temperature in your data center. Engineers are working on more sophisticated technologies for both computers and cooling equipment.
In the early days of data centers, computer equipment was kept at very cool temperatures — from 68 F to 70 F. These temperatures were mandated by computer manufacturers, who would not guarantee their equipment at higher temperatures. However, in 2008 the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) revised the guidelines to temperature band of 64.4 F to 80.6 F. "What is so powerful about these new recommended ranges is that they apply to legacy IT equipment," says Don Beaty, president of DLB Associates.
Using the higher end of the new temperature ranges can significantly reduce cooling energy use in chilled water systems. "Normally the water in the chiller would be cooled to 44 degrees, but if they take it to 50 degrees, it requires half of the energy," says Jim McEnteggart, vice president of Primary Integration Solutions.
Some data centers are running at only slightly higher temperatures, says Paul Mihm, executive vice president, technical services group, of Rubicon, "because the time to reach critical temperature is significantly shorter in the event of a failure." One solution, says Mihm, is to have a backup system to exhaust hot air out of the space. Most environments could withstand a short period of heat until the backup system kicked in, he says.
Another option is thermal energy storage using tanks of cold water. In water-cooled systems, the tank could be used to pump cold water through the system very quickly when a facility switches to emergency power.
While the type of data center will, in large part, determine tolerance of the new ASHRAE standards, geography also plays a role, since a hot climate will likely have a lower threshold for higher temperatures. If the data center needs to be rapidly cooled off, the outside air will not be much help, so there is less margin of error.
2. Ways to protect data centers from fire
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.