Project Planning & Cost

Gas Suppression System Technical Specification: Checklist

A gas suppression system specification should clearly define the design standard and its edition, the protected volumes, the agent, the design concentration and hold-time target, component approvals, detection and alarm logic, room integrity testing and pressure relief, commissioning documents and maintenance terms. This page collects those items as a checklist.

A gas suppression system technical specification is the document that lets bids from different contractors be compared on the same technical basis. It should clearly define the design standard and its edition, the protected volumes, the agent, the design concentration and hold-time target, component approvals, detection and alarm logic, room integrity testing, pressure relief, commissioning documents and maintenance terms. An incomplete specification can lead to choosing a low-priced bid with a narrower scope.

The list below is not a specification template; it is for checking whether a specification you write or receive covers these items. You can download a printable PDF version.

1. Scope and Standard

Design standard and its edition: EN 15004 / ISO 14520 or NFPA 2001; the relevant CO2 standard for CO2. One standard applied consistently to design, equipment and calculation
List of protected volumes: room name, net dimensions, raised floor and ceiling voids separately
Occupancy profile of each volume: normally occupied, occasionally entered or normally unoccupied
System architecture: one system per room (Stand Alone) or a shared cylinder bank with selector valves (Multi-Zone)

2. Agent and Design

Agent family or acceptable agents, with the selection rationale (see the agent comparison table)
Which fire class and safety factor the design concentration is calculated for
In occupied spaces: NOAEL for chemical agents, and the NFPA 2001 concentration and exposure-time limits for inert gases, not exceeded
Discharge time requirement and hold-time target (design concentration and hold time)
Hydraulic calculation with the system manufacturer’s approved software, with the outputs handed over
Cylinder location, cylinder room and distance to the protected room

3. Components and Approvals

Cylinders, valves, actuators, selector valves and nozzles covered by the same system approval (bodies such as UL, FM, LPCB, VdS; TPED/PED for pressure vessels)
Pipe material, fittings and pressure class suited to the system pressure; pipework pressure and leak test
A control panel approved for extinguishing control
For HFC systems, the registration and certified-personnel duties under the applicable fluorinated gas regulations

4. Detection, Alarm and Control

Detection type and logic that reduces false discharge (cross-zoning or double-knock; aspirating early warning where needed)
Pre-discharge audible and visual alarm, time delay, “gas discharged” sign at the door
Location and behaviour of manual release and abort buttons
Automatic shutdown of ventilation, air conditioning and dampers on discharge; monitoring link to the building fire alarm

5. Room Integrity and Pressure Relief

A door fan test before commissioning, with the report handed over
Remedial sealing and retesting included in scope if the room fails
Assessment of the positive and negative discharge pressure; a pressure relief vent where needed (pressure relief)

6. Commissioning and Handover Documents

Functional tests: detection, alarm, delay, manual release, abort, damper and ventilation shutdown
Handover: as-built drawings, hydraulic calculation report, door fan test report, cylinder fill records, product approval documents, operation and maintenance instructions, staff training record

7. Maintenance

According to summaries citing the 2012 edition of NFPA 2001: agent quantity and pressure checked at least every six months, the system inspected and tested annually, the protected room inspected for changes at least every 12 months; no actual discharge test is required. The current edition of the standard used on the project governs.
Periodic inspection of cylinders and hydrostatic testing and refill terms

To review your specification against this list or get help preparing one, see our design engineering service or contact us through the quote form.

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Technical Specification Checklist
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Frequently asked questions

Should the specification name the agent?

If occupancy, cylinder room space and environmental criteria are known, the agent family should be specified. If not, list the acceptable agents and the selection criteria so that bids are compared on the same basis. CO2 should only be specified for normally unoccupied spaces.

How should the design concentration be defined?

Rather than a number, state which edition of which standard and which fire class the calculation follows. Require the calculation to be done with the system manufacturer's approved software, the NOAEL and NFPA 2001 exposure limits not to be exceeded in occupied spaces, and the hold time to be verified by a room integrity test.

Should the room integrity test be in the specification?

Yes. State that a door fan test is done before commissioning, which standard the report follows, that remedial sealing and retesting are the contractor's responsibility if the room fails, and that the report includes an assessment of pressure relief for the discharge pressure.

To apply this guide to your project, see our gas fire suppression services and every system option on our home page, or contact us through the quote form.

Last updated: 26 October 2026