Three-quarter view of a deep ivory blower filter unit with blue centrifugal blower cover

FFU and Terminal Air Purification Equipment

Blower Filter Unit (BFU)

A deeper ceiling clean-air unit using a dedicated centrifugal blower to overcome duct, damper and final-filter resistance at elevated airflow.

High-Pressure Centrifugal Blower
Ducted or Recirculating Inlet
Perforated Air Diffuser
Large Airflow Capacity

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Product Introduction

The blower filter unit houses a forward- or backward-curved centrifugal blower above a full-size HEPA or ULPA filter in a deep insulated enclosure. Unlike a shallow grid FFU, the BFU is designed with enough chamber height for a larger scroll or blower wheel and can accept a round duct collar, inlet damper or recirculating top intake. An internal perforated plate distributes the higher-volume discharge over the filter surface. The format is suited to turbulent-flow rooms, high air-change zones and ceiling positions where a long duct path or loaded filter creates more resistance than a compact FFU can handle.

Key Features

A dedicated centrifugal blower develops useful static pressure for ducted inlets, dampers and deeper final filters.

The large pressure chamber reduces direct fan imprint before air reaches the HEPA or ULPA surface.

A removable perforated plate smooths the discharge and protects the downstream filter face during service.

Duct-connected and self-recirculating intake arrangements use the same ceiling-mounted enclosure platform.

Customer Product Concerns

Compact FFUs can lose airflow when the air path includes long ducts, dampers or a heavily loaded final filter.

Supply volume falls below target when duct and terminal pressure losses are added together.The larger centrifugal blower provides a higher available static-pressure range than a shallow axial module.

A concentrated blower outlet produces a visible high-velocity patch at the centre of the diffuser.The deep plenum and perforated equalising plate distribute pressure before final filtration.

A central air handler cannot independently trim airflow to one room or process zone.Each BFU can use its own speed setting or damper to balance the local ceiling supply.

Filter replacement requires dismantling the complete blower housing from above.A separated lower filter section permits the final filter and diffuser to be removed without lifting the blower assembly.

Typical Applications

High air-change cleanroomsDucted pharmaceutical supply pointsElectronics packaging roomsFood processing clean zonesLarge clean booths and corridors

Technical Parameters

Typical BFU enclosure and filter ranges for cleanroom ceiling service are shown below.

Core Material	Centrifugal blower, micro-glass HEPA or ULPA filter and optional closed-cell acoustic liner
Panel Thickness	500-750 mm overall housing depth
Effective Width	650-1300 mm nominal ceiling module width
Maximum Length	Up to 1450 mm standard housing length
Steel Facing Thickness	1.0-1.5 mm powder-coated steel or 304 stainless-steel blower-filter casing
Core Density	Approximately 24-48 kg/m³ density for optional closed-cell acoustic insulation
Thermal Conductivity	Approximately 0.033-0.040 W/(m·K) for the optional closed-cell acoustic liner
Surface Finish	Ivory-white powder coat or brushed 304 stainless steel with stainless perforated diffuser
Joint Type	Flanged duct inlet with gasketed blower access panel and compression-seal or gel-seal final filter
Customization	Available based on the intended application and operating environment.

Available Options

Forward- or backward-curved centrifugal blowerRound duct inlet or recirculating top grilleHEPA H14 or ULPA U15 final filterStepped, inverter or EC airflow control

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