Forward Curved Centrifugal Fan Guide | Specs & Selection

Centrifugal fans with forward-curved impellers (forward-curved blades), made of galvanized steel, are suitable for providing positive pressure in escape stairwells or for supplying air to designated areas. It should be noted that these fans are not suitable for exhaust or extraction applications and are not approved for such use.

The impeller material for centrifugal fans shall be galvanized steel.

The rain hood shall be made of galvanized steel and designed to prevent snow and rain from falling onto the motor base, bearings, belts, and electric motor, while still allowing visual access to the belts.

The shaft shall be made of stainless steel 304, resistant to rust and corrosion.

Bearings shall be of the UCP type, manufactured in Japan (genuine), with brands such as FYH or ASAHI or equivalent imported ones, and equipped with grease hoses for lubrication.

Fan belts shall be type A (up to size 40) and type B (from size 45 and above), manufactured in South Korea or Germany.

Pulleys shall be made of aluminum; for sizes 56 and above, cast iron may also be used.

Protective guards for the outlet openings (discharge side) shall be made of electroplated metal mesh with electrostatic or epoxy powder coating, to ensure safety and prevent birds from entering the fan.

The electric motor shall be of the ELECTROGEN or MOTOJEN brand (380 V, IP54, 55, Class-F). The use of 220 V motors is not recommended due to higher noise levels, vibration characteristics, and energy consumption.

Impellers must be statically and dynamically balanced using a portable balancing device in accordance with ISO-1940, and a certificate of compliance shall be issued.

The K correction factor for pressure drop due to altitude differences above sea level shall be applied for each city.

All fans must have a nameplate containing technical specifications and a unique fan identification number.

The manufacturer shall guarantee all moving parts (impeller, shaft, pulleys) for 24 calendar months or 30 months from the date of delivery, and shall provide after-sales service for at least 15 years. Additionally, the manufacturer shall guarantee fan belts for 2,000 operating hours and bearings for 6,000 operating hours. The manufacturer must also provide the buyer with all necessary information regarding proper installation, periodic maintenance, and dimensional drawings.

After manufacturing, appropriate conditions shall be provided at the factory site for conducting technical tests on the equipment, including airflow measurement using a duct and creating pressure drops up to the design point in accordance with AMCA 210 / ASHRAE 51; vibration measurement and dynamic balancing tests in fully assembled condition per ISO-1940 G2.5 using a portable dynamic balancing device; sound level (dB) intensity measurement; current draw; and other relevant technical parameters.

Utility fans must be equipped with a double steel channel base frame and suitable vibration isolators to prevent vibration transmission to the fan structure.

Angle frames shall be of adequate thickness with oven‑cured paint coating.

Full electrostatic oven‑cured paint coating shall be applied to all fan components.

Suitable lifting hooks shall be provided to facilitate handling and transportation of the equipment.

Drain plugs shall be incorporated to enable easy cleaning of the inside of the casing.