QP - QuietPack In-line Centrifugal Fans



The Quiet Pack in-line acoustic fans shall be as supplied from Roof Units, designed around a high performance centrifugal impeller, offering a highly efficient, quiet and compact in-line acoustic fan.

The Quiet Pack fan shall be manufactured from prime quality galvanised sheet steel, for mounting internally as standard or with a special treatment for externally mounting, ensuring a robust in-line fan for those tough site conditions.

Quiet Pack casings shall be internally treated with an ‘O’ class rated acoustic foam, which offers the benefits of excellent low level duct bound and breakout sound levels, in addition self extinguishing properties, zero burn rate, resistant to ignition, and no toxic fumes.

Quiet Pack fans 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 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 Quiet Pack in-line acoustic fans. All manufacturing progressed of the Quiet Pack fan units are computer designed and controlled to BS EN ISO 9001 Standards.


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 DIN 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 from -15ºC to +40°C and atmospheres up to 95% RH.

All sizes are ideally suitable for speed control by electronic or voltage reduction. Roof Units would recommend that a voltage reduction Auto Transformer speed controller is used with all Quiet Pack units to ensure minimum noise levels during speed control and to eliminate any possibility of harmonic noise levels which occur when using electronic speed controllers at lower speeds.


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:

• Auto Transformer Speed Controllers
• Electronic 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
• Weatherproofing



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)
QP100B 268 363 171 272 97 14
QP125B 268 363 171 272 122 14
QP150B 322 400 203 336 147 14
QP160B 322 400 203 336 157 14
QP200B 322 400 203 336 197 20
QP250B 472 614 320 499 247 25
QP315B 530 630 300 560 312 33
QP400B 530 630 300 560 397 50
QP500B 530 630 263 560 497 75



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