FB - Fan Box In-Line Centrifugal Fans



The Fan Box In-Line fans shall be as supplied from Roof Units, designed around a high performance forward curved centrifugal impeller.

The casing shall be specially designed to allow the unit to be mounted via drop rods or anti vibration mounts, ensuring a quick and easy solution to installation of the Fan Box in-line duct fans. All manufacturing of the Fan Box units are computer designed and controlled to BS EN ISO 9001 Standards.

The units shall be manufactured from prime quality galvanised sheet steel.

The Fan Box range are to be suitable for circular ducting ranging in sizes 100, 125, 150, 160, 200, 250, 315, 400 and 500mm, with air volumes from 0.064m3/s to 1.08m3/s and pressure development of up to 430Pa.


The forward curved centrifugal impellers shall be aerodynamically designed, utilising computer technology. The motor and impeller shall be factory matched, statically and dynamically balanced on precision machines, to ISO 1940 Grade 6.3., to give quiet, vibration free running. The aerodynamic blades and motor housing shall be manufactured from prime quality galvanised sheet steel.


Motor insulation Class B, suitable for operating temperatures up to +40°C and atmospheres up to 95% RH. All sizes are ideally suitable for speed control by electronic or voltage reduction.


The fan performance, shall be in accordance with tests to BS848 Part 1 1980, with the fan sound levels, measured in a reverberant chamber in accordance with BS848 Part 2 1985.

Quality Assurance

Design and manufacture shall be in accordance with the standard for quality management systems BS EN ISO 9001:1994.


A full range of accessories are available with the Fan Box range of fans such as:

• Electronic Speed Controllers
• Auto Transformer Speed Controllers
• D.O.L. Starters
• Standard, Acoustic & Thermal Flexible Ducting
• Pre-Panel or Secondary Bag Filters
• Electric Heater Batteries
• Backdraught Shutters
• In-Line Attenuators
• Wall & Roof Terminals
• Fast Clamps



1. Drop rods (up to M8) can be used on the base flange when mounting the unit upside down.

2. AVM’s can be fitted to either side or the base of the unit.

3. An access provision above the lid of each unit, no less than the respective A dimension must be made.

Unit Size A B C D E Approx Weight (kg)
FB100B 268 363 171 272 97 13
FB125B 268 363 171 272 122 13
FB150B 322 400 203 336 147 13
FB160B 322 400 203 336 157 13
FB200B 322 400 203 336 197 18
FB250B 472 614 320 499 247 23
FB315B 530 630 300 560 312 33
FB400B 530 630 300 560 397 48
FB500B 530 630 300 560 497 72



There are no softwares available for download for this particular product.