FM-200 Clean Agent Fire Suppression for a Bangladesh Bank's Primary Data Centre

When the data centre was constructed in 2018, the building's existing wet-pipe sprinkler system was extended into the room as a temporary measure — with the explicit understanding among the facilities team that it would be replaced with an appropriate suppression system before the room went live. This replacement never happened. By 2026, the bank had 120 production servers operating under a ceiling fitted with standard wet-pipe sprinkler heads — a configuration that the bank's own IT risk register described as "critical unmitigated risk."

The danger of a wet-pipe sprinkler system in a live server room is not merely theoretical. A single accidental sprinkler discharge — triggered by a construction worker's heat gun on the floor above, a faulty head, or a genuine fire — would activate all heads in the zone simultaneously, releasing hundreds of litres of water across 120 servers. The bank's IT department estimated that a full discharge event would cause irreparable damage to all server hardware, with replacement cost estimated at BDT 4.5 crore, plus days or weeks of core banking system downtime while replacement hardware was procured and configured from scratch. The bank had no live hot standby site that could absorb full operations immediately.

Bangladesh Bank's ICT Security Guideline v4.0 includes a specific requirement that primary data centres must have appropriate fire suppression systems — and specifically references clean agent or pre-action systems as appropriate for IT environments, implicitly disqualifying wet-pipe water sprinklers. During the bank's 2025 Bangladesh Bank IT security examination, the wet-pipe sprinkler situation was escalated from a recommendation to a formal directive, requiring the bank to implement a compliant suppression system within 120 days. Non-compliance would be reportable to the Bangladesh Bank board as a material IT risk management failure.

The bank's insurance policy added a third pressure vector. The cyber and technology liability insurance policy, renewed in early 2025, included a clause requiring the policyholder to maintain fire suppression appropriate to the server environment. The bank's insurance broker informally advised that in the event of a water damage claim from a sprinkler activation in a server room where compliant suppression had not been installed, the insurer would likely contest the claim on the basis of the policy condition breach.

The 120-day Bangladesh Bank timeline was non-negotiable. The bank needed a vendor who could survey, design, procure, and install a complete suppression system — including early warning detection, clean agent agent release mechanism, and all safety interlocks — within that window.

SSAL designed and installed a complete integrated fire detection and suppression system for the data centre, conforming to NFPA 2001 (Standard on Clean Agent Fire Extinguishing Systems) and NFPA 72 (National Fire Alarm and Signaling Code), and meeting the Bangladesh Bank ICT Guideline v4.0 physical security requirements for data centre fire protection.

Pre-Installation Room Integrity Assessment: Before finalizing the FM-200 system design, SSAL conducted a room integrity blower door test per ISO 14520 / NFPA 2001 Annex B. The test identified three significant air leakage paths: a cable penetration through the floor slab (inadequately sealed during original construction), a gap around an HVAC supply duct entry, and a door undercut that exceeded tolerance. These were sealed with appropriate fire-rated sealant and door sweeps before system design was finalized. The post-remediation integrity test confirmed the room held sufficient pressure to guarantee 10-minute agent retention at the design concentration.

Honeywell FM-200 Clean Agent Suppression: The suppression system was designed using Honeywell ECARO-25 (FM-200 / HFC-227ea) as the clean agent, selected for its UL/FM listing, zero ozone depletion potential, and proven effectiveness in IT environments. Agent quantity was calculated per NFPA 2001 to achieve an 8.5% by volume concentration — above the minimum extinguishing concentration for Class A/B/C fires — within the 280 square metre, 3-metre ceiling room volume.

Two 50kg FM-200 cylinders were installed in a dedicated suppression equipment enclosure adjacent to the server room, connected via stainless steel high-pressure piping and nozzles distributed through the server room ceiling to ensure uniform discharge. The system is configured as a total flooding system covering the entire room volume. A manual abort station is mounted at the server room exit, allowing personnel inside the room to halt the discharge countdown during the pre-discharge delay period (30 seconds from detection to discharge).

Siemens Cerberus PRO Addressable Fire Detection: Very Early Warning Fire Detection (VEWFD) was provided by a Xtralis VESDA-E VEA aspirating smoke detector, which continuously draws air samples from 12 points throughout the server room — including under-floor, in-rack (via capillary tubes), and ceiling level. The VESDA system provides four threshold alert levels: Alert, Action, Fire 1, and Fire 2. The Fire 2 threshold, set conservatively above the highest sensitivity level, triggers the FM-200 suppression discharge sequence through the Siemens Cerberus PRO fire alarm control panel (4-loop FACP).

The Siemens Cerberus PRO panel provides the pre-discharge sequence management: upon Fire 2 detection, the panel activates audible and visual pre-discharge alarms (bells and strobe throughout the room and adjacent corridor), closes HVAC dampers via BMS interlock to prevent agent dilution, cuts power to non-essential equipment via relay output, initiates the 30-second countdown, and releases the FM-200 solenoid valve to discharge the agent. A manual release station is also provided at the server room entrance for security override.

Integration with Building Fire Alarm: The data centre suppression panel is networked to the building's main Siemens Cerberus PRO fire alarm system via the Cerberus PRO ring bus, ensuring that a suppression discharge event also triggers full building evacuation alarm.

Safety Interlocks and Signage: The system includes abort/manual release stations at both sides of the server room door, door-mounted suppression system status displays, mandatory NO RE-ENTRY signage (as per NFPA 2001 post-discharge protocol), manual lockout key switch for maintenance mode, and automatic door release to ensure egress doors are unlocked during a discharge event.