Fire Protection in Data Centers

Fire Source.

Based on comprehensive audits conducted in numerous data centers, the primary sources of fire incidents in data centers are typically attributed to electrical factors such as cable overheating, loose connections, short circuiting, as well as issues related to light fixtures and dust accumulation.

Purpose of Fire Suppression System.

·      Early detection of fire

·      Minimum or no damage to human and equipment installed in data center

·      Human friendly gas to be used for suppression

Fire Classes. Following are the fire classes: -

·       Class A Fire involves solid material like wood, cloth, paper, rubber etc.

·      Class B  Fire involves flammable liquids like petrol, oil, greases, paint etc.

·      Class C  Fire involves glasses and chemicals

·      Class E  Energized Electrical Equipment like electric board, generator, machinery etc.

Extinguishers used to Extinguish Fire. Depending of fire class, following extinguishers are used to extinguish fire: -

·      Halotron                               For class A, B, C & E fires

·      Dry Chemical Powder          For class A, B & C

·      CO2                                     For class C & E fires

·      AFFF Foam Type                  For class A & B fires

·      Water Type                           For class A & B fires

Detection System used in Data Centers

·      Very Early Smoke Detection Apparatus (VESDA)

·      High Sensitive Smoke Detection (HSSD)

VESDA is a brand name that has become a common name for high sensitive smoke detection (HSSD). VESDA works by continuously drawing air into a distributed pipe network via a high-efficiency aspirator. The air sample then passes through a dual-stage filter. The first stage removes dust and dirt from the air sample before it enters the laser detection chamber. The second, ultra-fine stage provides an additional clean-air supply to keep the detector’s optical surfaces free from contamination, ensuring consistent absolute detection and long detector life as well as minimizing nuisance alarms. From the filter, the air sample goes through the detection chamber where it is exposed to a laser light source. When smoke is present, light is scattered within the detection chamber and is instantly identified by the highly sensitive receiver system.

Following are the two main models: -

a. VESDA VLF-500

b. VESDA VLF-250

Smoke Detectors to Fire Detection/ Fire Detection & Suppression Panels

         Smoke detectors used in fire detection/ fire detection and suppression panels are commonly based on ionization or photo-electric sensors.

·      Ionization Detector. When smoke enters this type of detector, the ion creates electric path setting an alarm condition.

·      Photoelectric Detector. When smoke enters this type of detector, deflection of light will activate photocell triggering alarm.

Fire Suppression System

·      Gases. Different type of gases is used in fire suppression which includes Halon 1301, CO2, FM200, NOVEC 1230, Inergen, Argonite, FE13 and Pyrogen. FM200 has been widely used in data centers as the gas is no harmful for human being however, the gas has now been restricted by many countries. NOVEC 1230, being human and atmospheric friendly, also known as green gas is getting popular for fire suppression systems.

·      How the System Works.

Zoning is done is fire suppression system. Zoning is an essential feature incorporated into fire suppression systems. When smoke is detected by any zone sensor, the system initiates a process wherein it awaits confirmation from a second zone sensor. The purpose of this dual-zone confirmation is to ensure the accuracy and reliability of the fire detection before taking further action.

Upon receiving confirmation from the second zone sensor, the system enters a brief preset time delay, allowing for additional assessment and verification of the fire situation. During this interval, the system activates visual and auditory alarms such as flash lights or hooters. These alarms serve to alert duty personnel and prompt them to take appropriate action.

Duty personnel are then afforded ample time to physically visit the premises and verify the presence of a fire, or they can remotely assess the situation through surveillance cameras. This additional verification step is crucial in order to prevent false alarms and unnecessary release of gas, thereby minimizing any potential risks or disruptions.

By incorporating zoning, time delays, and verification process, fire suppression systems ensure a robust and reliable approach to fire detection and response, promoting both safety and efficiency in safeguarding life and property.

Fire Suppression System Maintenance

         Based on my personal experience, I suggest you to carry out following type of fire suppression system maintenance: -

Daily checks. Check for errors on detection / suppression panel and check gas pressure.

Monthly Inspections. Monthly inspections are the standard set by NFPA for fire suppression system.

Semiannual Inspections. Fire suppression system must be checked completely at least every six months. This includes removal of actuator from gas cylinder and testing it by giving fire signal, testing of manual gas release, stopping gas release timer, cleaning and testing of all sensors.

Demo Video- Simulation

         Please see the simulation video to see how FSS works.

 About The Author

Writer is an electrical engineer having experience in data center power infrastructure. Mr. Hussain has spent last decade in data center facility management, data center operations, data center planning, data center construction, procurement and contract management. He holds a bachelor of electrical engineering degree from NED UET (https://www.neduet.edu.pk/) and master of engineering management degree from NUST (https://nust.edu.pk/) Pakistan. He is certified data center professional (CDCP) from EXIN, Netherland and certified project management professional (PMP) from PMI, USA.