Gas Fire Suppression Systems

A gas fire suppression system extinguishes a fire by displacing or absorbing oxygen and heat with a clean agent: no water, no residue, no clean-up. They’re used wherever water-based suppression would do more damage than the fire itself: data centres, comms rooms, switchgear rooms, archives, museum stores, MRI rooms and laboratories. If your asset register includes equipment that can’t be replaced overnight or data that can’t be re-keyed, gas is the right answer.

Inert gas (e.g. ProInert IG-55, Inergen IG-541) is a blend of naturally-occurring gases (argon, nitrogen, CO₂) that reduces oxygen below the combustion threshold while remaining breathable. Larger cylinder banks, slower discharge, environmentally neutral. Chemical agents (FM-200 / HFC-227ea, Novec 1230) are synthetic clean agents stored as a liquid that vaporise on discharge, absorbing heat and interrupting the combustion reaction. Smaller cylinder count, faster discharge (typically 10 seconds), but higher global-warming potential (FM-200) or premium cost (Novec 1230). Choice depends on room volume, environmental policy and budget.

A site survey establishes room volume, integrity, ventilation, occupancy and existing detection. From the survey we model agent quantity to BS EN 15004 (gaseous extinguishing systems) and BS 6535-2 (clean-agent selection), specify the cylinder room, draft pipework and nozzles, and integrate the detection and release control. Typical timelines: small single-zone install 2-3 weeks on site; mid multi-zone 4-6 weeks; large data centres phased over maintenance windows. Design and procurement add 4-6 weeks before site work begins.

Every system is quoted on survey, and we price competitively against the commercial market. Cost is driven by: room volume (the single biggest factor), agent choice, enclosure integrity, integration scope with the existing fire alarm and BMS, access difficulty, and commissioning depth. A single-zone server room and a multi-zone data centre with redundant agents and full integrity reporting sit a long way apart, which is why a published price band tells you very little about your building. Your site survey produces a fixed, itemised quote covering design, installation, commissioning and the first year of integrity testing, so you can compare like for like. Annual servicing is quoted per protected zone.

Properly designed systems are designed for human-occupiable spaces at their design concentration. Inert systems reduce oxygen to a level that no longer supports combustion but remains breathable; Inergen specifically contains a small CO₂ component that stimulates deeper breathing during discharge. Chemical agents at design concentration are safe for occupants. All systems include a pre-discharge alarm with an evacuation period so the room can be vacated before agent release.

Yes, we integrate with every major fire alarm platform (Apollo, Hochiki, Advanced, Gent Vigilon, Honeywell). The fire alarm provides cross-zoned detection; the suppression release control sits alongside it on its own listed-and-approved release panel, with the cause-and-effect engineered to require confirmation from two independent detectors before discharge. That prevents accidental discharge from a single false alarm.

BS EN 15004 and ISO 14520 set a periodic inspection regime with a thorough service by a competent person at least annually; and a container contents check at least every six months (ISO 14520-1, Clause 9), which is why two engineer visits a year is the norm before manufacturer schedules and insurer conditions are added; the detection and release side is serviced to BS 5839-1 at approximately six-month intervals. At every visit halocarbon cylinders are weighed or level-checked and inert cylinders pressure-checked with temperature correction. The enclosure must be checked at least every 12 months for changes that could affect leakage, with a room integrity test (the door-fan test) repeated whenever a change cannot be ruled out by inspection or after any alteration: cable penetrations, new ductwork, moved partitions. We retest annually as standard practice, because a visual check rarely rules out change in a working room. Hoses are examined every year. The cylinders themselves are transportable pressure receptacles, so under the Carriage of Dangerous Goods regulations (which apply ADR in the UK) they are due a periodic inspection and hydrostatic test at set intervals, ten years for most of the seamless steel cylinders used in suppression, counted from the date stamped on the cylinder; a cylinder past its test date cannot be refilled, which is why the ten-year point belongs in the maintenance programme rather than being discovered after a discharge. The full regime is in our servicing intervals guide; contracts are quoted per protected zone on survey.

Yes. We run a free transition audit when we take over an existing system: compliance gap analysis, asset register reconciliation, and a one-off catch-up service if anything has slipped through the previous contractor. Our maintenance contracts have no long lock-in (90 days’ notice) and no hidden recharge clauses. Whatever your incumbent has on the system, we’ll service it: we’re cross-trained on every major manufacturer.

Yes on both counts, today. FM-200 (HFC-227ea) is caught by the GB F-gas phasedown, which pushes recharge cost and lead time up rather than making the system unlawful. Novec 1230 is the former 3M brand name for FK-5-1-12: 3M’s production ended in 2025, but the agent is still manufactured generically with UL-listed and FM-approved hardware, and the HSE’s PFAS restriction covers firefighting foams, not gaseous agents. Any future restriction would arrive with transition periods measured in years. We service and recharge both, and we will tell you plainly when a replacement makes more sense than a recharge. See our chemical agent page and the PFAS stewardship guide.