Centrifugal Duct Fan – ISQ
  • Volume Capacity: 600~50,000 m³/h (353~29,412 CFM)
  • Static Pressure: 500~900 Pa (2~3.61 in.WG)
  • Drive Types: Direct/ Belt drive
  • Installation Methods: Base mount/ Ceiling hung/ Duct mount
  • Applications: Ducted ventilation / Filtered ventilation / Sound-proof fan box / Explosion-proof ventilation / Smoke exhaust


Novel Product Design  

— Great aerodynamic characteristics and sound performance.

— High efficiency, wide range of performance without overload

— G2.5 grade balancing level (whereas common products have only G6.3 level)

Aerodynamic Design

— CFD simulation technology is used for optimized design which is also validated through repeated trials.

— Flow field characteristics are presented in the front disc and inlet cone.

— Control on flow passages: airflow is well controlled for higher system efficiency.

— Blades are mounted with the angle pitches optimized.

Optimized Design for Structure

— FEA method is used to analyze stress and improve performance.

— Different product models are specified with different strengthening structures to make products more reliable.

— Structural stress is prevented through using the riveting technology.

Updated Wheel

— The ISQ wheel is upgraded to the 4th generation.

— Its overall performance is 5-10% greater over the 3rd generation.

— Its overall sound is 2-3 dB(A) less than the 3rd generation.

High-standard Processes

— Excellent air performance is achieved as the wheel cone and inlet cone are both formed through the spinning process.

— By using the inlet cone, smooth airflow can be produced.

— Formed through the punching process, blades have a reliable quality standard.

— Special fixtures and other tools are applied so that blades are mounted at the right positions.


Wide Range of Performance and Lower Investment Required

— The ISQ Wind-Surfer wheel has been upgraded to the 4th generation that has a wider scope of pressure options and lower sound than its 3rd generation.

— The maximum diameter of the wheel is one meter. This means fewer fans are needed and upfront investment will be lower.

–The scroll is not needed. So there is an overall smaller fan size and easy installation.

Inline Centrifugal Type as a Better Solution to Sound

— The speed of the inline centrifugal type is 20-30% less than the axial/mixed flow types, which is a fundamental difference.

— The sound pressure level is reduced by 10-15 dB(A).

— This has fundamentally resolved the issue of sound.

Scroll-free Structure

— Airflow is directly drawn into the wheel for pressurization which is a much improved airflow pattern.

— As the direct drive structure generates no dust, the product can be well used in clean rooms in microelectronics, food and medical industries.

AMCA Seal: for Sound and Air Performance

— ISQ fans have won the AMCA Seal for Sound and Air Performance.

— ISQ fans are labeled with AMCA Seal for Sound and Air Performance.

Lower Installation Costs from the Square Design of Different Discharge Arrangements

–The square/ round connectors and ring flanges are no longer needed as square inlet/outlet flanged sleeve are provided as standard accessories.

— The Installation period is shortened and lower costs are required for duct connection.

— The motor can be installed at different positions.

— Easy installation is achieved from the multiple discharge positions.


There shall be a close match between the motor and the fan load. The motor shall have a degree of protection standard IP55 and an insulation class F. Its bearing shall be of ball type and require no lubrication.

Fan Type 

The ISQ fan shall be equipped with the backward inclined centrifugal wheel made of aluminum and it shall be of inline centrifugal type. To ensure the fan has smooth air movement, the wheel cone shall be designed with a curved section. Each wheel shall undergo static and dynamic balancing tests and reach AMCA 204- G2.5 balancing level (Standard ISO 1801940).

Fan Housing

Material: Galvanized steel sheet (Option: cold roll steel sheet coated with electrostatic epoxy) shall be used for the fan housing. The thickness of the housing shall be able to support the drive unit and motor.

Shape: The housing shall be square-shaped and have square flanged sleeves so that square/ round connectors are not needed. Different discharge arrangements shall be made available. In order for easy motor maintenance and replacement, a sizable access door shall be designed on both the left and right sides.

Drive Unit (For belt driven models only)

Shaft: Heat treated through soaking furnace, the shaft shall reach a hardness level of HB370. Hard film treatment shall be made on the surface to avoid corrosion. The shaft and the wheel shall be dynamically balanced together. It shall have its speed designed at least 25% more than the maximum running speed of the fan.

Pulley: The size of the pulleys shall be at least 150% of the driving power. Pulleys shall be made of cast iron and keyed to the motor shaft. For the purpose of easily removing the pulleys, conical type bushings shall be used.

Bearing: The shaft shall be supported by at least two bearings so that vibrations can be offset. The bearing shall have a minimum L10 life of 80, 000 hours at the maximum cataloged speed. It shall be metal pedestal ball bearing that is permanently sealed and can be lubricated.

Drive Support: Thick powder-coated and anti-corrosive steel sheet shall be used to support the drive unit. By adjusting the bolt at the motor base, the belt tension shall be available for adjustment. The fan shaft and motor shaft shall be made parallel.

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