PXF

PXF | Floor standing chemical gas extraction unit

The PXF is a floor-standing extraction unit designed to remove gas and smoke after a fire suppression system has discharged. Because both inert gas and chemical agents are heavier than air, they sink towards the floor once released. The PXF is therefore installed at floor level or inside a floor void, ensuring the gas is safely extracted from the protected room without leaving residue, trapped agent, or pockets of low oxygen.

The ducting can be positioned horizontally or vertically, allowing the installer to tailor the unit to the room layout. All PXF models provide extraction only and must be paired with a pressure relief vent for safe make-up air, as required by FIA guidance (01-02-2012).

PXF for inert gas suppression

In inert gas systems, the room’s oxygen level is reduced to extinguish the fire. Once the event is over, oxygen levels need to return to normal quickly, and any remaining inert gas must be removed from the room. The PXF safely extracts this gas from floor level, ensuring the environment becomes safe for re-entry without compromising system performance.

• Ideal for rooms protected with IG-55, IG-541, IG-100 and similar inert gases.
• Mounted low to maximise efficiency, since inert gases settle after discharge.
• Used with the SHX-UN universal pressure relief vent for correct airflow and pressure stabilisation.

PXF for chemical gas suppression

Chemical agents such as FM-200 or FK-5-1-12 knock down the fire rapidly, but the agent also sinks after discharge. The PXF enables fast and controlled extraction of the spent gas and smoke, restoring visibility and air quality inside the room.

There are two versions:

1. Standard PXF Chemical Gas Extract Unit

• Provides gas extraction only (per FIA guidance).
• Must be installed with a DUX duflow pressure relief vent for pressure relief and fresh air flow.

2. Two-Way PXF Chemical Gas Extract Unit

• Provides both gas extraction and two-way pressure relief in a single unit.
• Can be supported with additional vents when larger amounts of make-up air are required.
• Designed for applications where both extraction and pressure balancing need to be managed by one integrated system.

The PXF kit 

Each PXF model is supplied as a complete extraction package, ready for installation. The contents differ slightly depending on whether you choose a 250 mm or 315 mm version, but typically include:

Core components

• Steel, powder-coated enclosure (RAL 9003 signal white)
• In-line fan sized to the duct diameter
• Floor-level plenum box for efficient gas intake
• Spiral ducting (approx. 2.4 m)
• 90-degree elbow section
• Male connectors, split rings, inline couplers
• Call point key switch for activation
• Matching pressure relief vent (SHX-UN for standard versions / DUX for two-way versions)

PXF250 and PXF315 variants

The two sizes differ mainly in the duct and fan diameter (250 mm or 315 mm). Each version includes all the necessary connectors and reducers required to integrate the extraction unit into the room’s airflow design.

Weather protection options

For external exhaust points, weather protection such as DWL weather louvre or an EXP open louvre can be added.