PXW

PXW | In wall inert gas extraction unit

The PXW is an in-wall extraction system designed to clear gas, smoke, and other by-products from a protected room after a gas fire suppression system has discharged. On its own, the PXW provides extraction only; when paired with a pressure relief vent, it becomes a complete relief-and-extraction solution.

The unit can be installed at either low or high level, depending on what needs to be removed from the room. Low-level installation is ideal for heavier residual gases, while high-level placement is used for smoke or hot gases that rise. Each PXW is supplied as a complete kit, making installation simple, efficient, and cost-effective.

PXW for inert gas suppression systems

The inert gas version of the PXW is an extraction unit designed to remove remaining inert gas from the room after discharge. To ensure the room can safely relieve pressure during the actual extinguishing event, it must be paired with an SHX-UN inert gas pressure relief vent. 

The SHX-UN handles the overpressure created during discharge, while the PXW handles the post-discharge extraction. The free area of the SHX-UN can be included in the room’s pressure relief calculations.

PXW for chemical gas suppression systems

The chemical gas variant of the PXW is built specifically for clearing residual agent from the enclosure once the system has discharged. Because chemical agents can create both positive and negative pressure during release, this setup is used together with a DUX two-way pressure relief vent. 

The DUX manages the pressure changes that occur during the extinguishing event, and the PXW takes over afterwards to extract the remaining chemical gas safely and efficiently. The DUX vent area contributes to the enclosure’s overall pressure relief requirement to help keep the room safe and compliant.

The PXW kit 

Every PXW unit is supplied as a ready-to-install wall-mounted extraction kit. While the exact specifications differ slightly between the inert-gas and chemical-gas versions, each kit contains everything needed to mount the unit at either high or low level in the protected enclosure.

Core Components

• Fully assembled steel in-wall housing (RAL 9003 signal white)
• Integrated extraction fan matched to the model’s capacity
• Internal duct section to channel gas from the room into the fan
• Mounting frame and fixings for secure installation
• Matching AFP pressure relief vent:
• SHX-UN for inert gas versions
• DUX two-way vent for chemical gas versions
• All required connectors and fittings for joining the extraction unit to the wall opening

PXW300 and PXW500 variants

The inert gas PXW is available in two sizes to match different room volumes and extraction requirements. The chemical PXW is only available as the PXW500. 

The two sizes differ mainly in the duct and fan diameter (300 or 500 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.