Gas Suppression Β· System Design

Get the design right,
or nothing else matters.

A gas suppression system is only as good as the calculations behind it. Gemini AMPM designs suppression to BS EN 15004 and ISO 14520 — the standards that govern agent quantity, discharge time and hold time. We select the agent, assess the enclosure, size the venting and integrate the detection. Then we prove it all on paper before anyone orders a cylinder.

Agent & concentration

The right agent,
at the right concentration.

Every gas suppression design starts with the same question: what are we actually protecting? The answer drives agent selection — inert gas for occupied, critical spaces; clean chemical agents where storage space is tight; condensed aerosol for compact enclosures. From there the numbers take over. Design concentration for the fuel class. Agent quantity for the room volume. Discharge time. Predicted hold time. All calculated to BS EN 15004 and ISO 14520, the twin standards that govern gaseous extinguishing systems.

For electronics and IT areas we work to BS 6266, the code of practice for protecting electronic equipment installations. It shapes the risk assessment: what a fire in that room would really cost, whether suppression is justified, and what detection should trigger it. The result is a design your insurer can interrogate and a system that will do its job — not a catalogue pick.

What we deliver

Scoped, delivered,
evidenced.

  • Agent selection — inert gas, clean chemical agent or condensed aerosol, matched to the risk, the room and the people in it
  • Concentration & quantity — design concentration and agent quantity calculated to BS EN 15004 / ISO 14520 for the fuel class and room volume
  • Hold-time prediction — how long the agent concentration must be retained, and whether the enclosure can actually deliver it
  • BS 6266 assessment — risk-based design guidance for electronic equipment installations, from server rooms to control suites
  • Venting & pressure relief — over- and under-pressure relief calculated so discharge never damages the enclosure it protects
  • Detection integration — coincidence detection, time delays, abort functions and a full cause-and-effect matrix for the installer
Enclosure & integration

Design the room,
not just the system.

An enclosure is part of the system. We assess it as one: room volume including floor and ceiling voids, leakage paths, door seals and dampers, and whether the fabric can hold the agent for the required time. Discharge also pushes room pressure up or down fast, so we calculate the pressure relief venting the enclosure needs — miss it, and a discharge can damage the very room it protects.

Then we wire the logic. Coincidence detection so one false alarm never dumps a cylinder bank. Time delays, hold-off and abort functions. Shutdown of ventilation and dampers so the agent stays where it’s needed. The output is a complete design package: drawings, calculations, cause-and-effect matrix and specification — ready to install, ready to price and ready to defend.

FAQ

Common questions on
system design.

What do BS EN 15004 and ISO 14520 cover?

They are the two closely aligned standards for gaseous fire extinguishing systems — BS EN 15004 is the European standard, ISO 14520 its international twin. Between them they set design concentrations for each agent and fuel class, discharge times, hold times, safety requirements for occupied spaces and the rules for hardware, installation and maintenance. UK insurers and fire engineers expect gas suppression to be designed to them. Ours always is.

How do you decide which agent to specify?

We weigh four things: the risk, the room, the people and the future. Inert gas suits occupied critical spaces and has no environmental question marks. Chemical agents win where cylinder storage space is scarce and speed matters most. Condensed aerosol suits small, normally unoccupied enclosures. Because Gemini designs and installs all three, the recommendation follows the risk assessment — not a product line we need to shift.

Can you design around our existing fire detection?

Yes. If your detection and alarm system is sound, we design the suppression interface around it: coincidence detection, releasing panel, time delays and cause-and-effect. If it needs upgrading, we can design and install that too — Gemini is BAFE SP203-1 certificated for fire detection and alarm systems, so the whole releasing chain sits under one certificated contractor rather than three subcontractors pointing at each other.

Next step

Talk to us about
system design.

A named engineer, not a call centre, comes back within 24 hours. Tell us the building and what you’re dealing with, and we’ll scope it properly.