Combustible Hydrogen (H2) Gas Detectors for Battery Rooms

Experts in Hydrogen (H2) Gas Detection

Battery Room Hydrogen Detection

Battery room safeguards are not generally well understood and yet as UPS systems see much more common use in data centers and Telcom, proper design, ventilation and other safeguards must be incorporated for safety, reliability and loss prevention. This discussion centers primarily on Hydrogen detection and ventilation, however the codes and standards are cited for more complete information. Hydrogen is produced during battery charging, which is a constant phenomena unless there is a power outage. The Uniform Fire Code and the International Fire Code and others permit Hydrogen levels as high as 1% by volume or 25% of the lower explosion limit.

Hydrogen has a wide flammability range (4% to 74% by volume), detonates (explodes) from 18% to 59%, and is very easily ignited. It burns with a pale blue, almost invisible flame, and can cause serious injury to personnel and severe equipment damage. Continuous ventilation can be employed in a battery room and the fan capacity should be at least the room area in square feet expressed as cubic feet per minute. One standard lists 12 air changes per hour and another 1 CFM capacity per charging ampere but not less than 6 air changes per hour. These ventilation standards apply only to ventilated batteries.  

In common practice, one or more Hydrogen sensors are ceiling mounted and either turn-on or modulate a ventilation fan.  The gas detection panel usually combines annunciation outside the door and supervisory notification for the accepted solution in compliance with the codes and standards. In high value data centers with large UPS systems, an optical flame detector may be used to detect fire. This is advisable as Hydrogen flames are pale blue and nearly invisible. Fire damage and power outage is extremely costly.

Download the Sensidyne Battery Back-up Application Note using the link below:

Battery Back-up Room Application Note

NFPA 76, Standard for the Fire Protection of Telecommunications Facilities 2009 Edition
OSHA 29 CFR 1926.441, Battery Rooms and Battery Charging
EN 50272-2 Safety requirements for Secondary Batteries and Battery Installations
NFPA 111: Standard on Stored Electrical Energy Emergency and Standby Power Systems, 2005
NFPA 111: Standard on Stored Electrical Energy Emergency and Standby Power Systems, 2005
Alarm notification to a remote location, manned 24/7/365 and capable of response