Prometheus 6

At 15 percent oxygen, it's safe for humans to enter.

Oh, hell, YOU'RE no fun... 

Data Centers Breathe Easier with Less Oxygen
Jeremy Kirk, IDG News Service
Friday, March 16, 2007 12:00 PM PDT

As data centers become hotter and more dense with servers, a greater chance for fire exists. But there's equipment on the market that applies a well-known method of halting fire: starving it of oxygen.

Only a few vendors are offering oxygen-deprivation systems, but interest in the technology is growing. It involves pumping air that has such a low oxygen content that a fire can't start in the data center.

Air is composed of about 21 percent oxygen, 78 percent nitrogen and 1 percent of other gases. Fire needs the oxygen to burn, and lower percentages of oxygen makes it more difficult or impossible for fire to start.

Wood stops burning when the oxygen content falls to 17 percent and plastic cables between 16 to 17 percent, said Frank Eickhorn, product manager for fire detection at Wagner Alarm and Security Systems GmbH in Hanover, Germany.

Wagner makes electric compressors that use a special membrane to remove some of the oxygen from the outside air, a system the company calls OxyReduct. The excess oxygen is exhausted, and the remaining nitrogen-rich air is pumped inside the data center.The lower oxygen content of the air is similar to being at an altitude of about 6,000 feet, Eickhorn said. He demonstrated with a lighter inside a sealed atrium Wagner has on display at Cebit. It won't light.