Tunnel Ventilation Fan – YFTNV
  • Volume Capacity: 7.9 ~ 70 m³/s
  • Thrust: 220 ~ 3,000 N
  • Drive Type: Direct drive
  • Installation Methods: Ceiling hung/ Sidewall mounted
  • Applications: Mainly used in tunnels, including metro tunnels, road tunnels, railway tunnels and underground car parks.



The hub and blades are casted with aluminum alloy of great strength. Blades are designed to have high efficiency and low noise. Heat treatment, X-ray flaw detection, tensile test and metal processing have been performed on the impeller and is dynamically balanced. The angle of the blades can be adjusted for different working conditions.


The motor can prevent heat and damp and is of squirrel cage and sealed type. It has a degree of protection standard IP55, an insulation class H. Reliable bearings (brand like SKF, NSK) are used to match the motor. Lubricant refill/drain hole, shaft temperature alarm and wiring box are installed on the outside of the housing.

Fan Housing and Mounting Brackets

CNC laser and plasma cutting machines are used. The hot-dip galvanizing or painting process is applied on the surface so that it is strong and won’t corrode. The design of mounting brackets is made according to the onsite conditions.


Silencers that are 1 times fan diameter are fitted at the inlet and outlet of the YFTNV jet fan. When noise requirements are quite demanding, it is recommended to use silencers that are 2 times fan diameter. Quality steel sheets are used for the outer shell. On the outside, the alkali-free fibrous glass cloth is used. The perforated steel inner liner is placed inside. In between, there is insulation material with super fine glass fiber. Flow filed and fan efficiency are improved with the streamlined nozzle.

Resistance to High Temperature

Obtaining CCCf (China Compulsory Certification for fans) certification, the YFTNV jet fan can be used for emergency smoke removal. It is designed to make the YFMRT fan run continuously for no less than 1 hour under 280°C and ensure no mechanical, electrical or structural failures occur.

Reversible Rotation

The YFTNV jet fan can be reversed smoothly. With a low moment of inertia, within 30 seconds, the fan can be reversed to the rated speed.

Easy installation and maintenance.


Thrust Test: Using the devices designed according to the ISO13350 standard, the thrust test is performed.

High Temperature Resistance Test: China National Centre for Quality Supervision and Test of Fixed Fire-fighting Systems and fire-resisting Building Components (Tianjin Fire Research Institute of MPS) performs the test.

Noise Test: On open areas (when air speed is around zero), the YFTNV jet fan fitted with silencers and the fan without silencers are tested. The data of sound pressure level is obtained at 10 meters from the fan 45-degree to the fan shaft.

Fan Efficiency: By using the thrust (N) and input power (kW), the fan efficiency is determined.

Tests on volume, mechanical operation, vibration, start-up time and switching time of reverse rotation are conducted in the INFINAIR laboratory according to national and industrial standards.

Structure Type

The YFTNV jet fan shall be of direct drive type. Airfoil blades shall be mounted on the impeller. High strength bolts shall be used to connect the silencers with the inlet and outlet. For safe fan operation, there shall be steel safety guard at the inlet and outlet.

Unidirectional and reversible types of YFTNV jet fan are available. For the unidirectional type, the direction can also be reversed under some situations and the reversed thrust is 50% to 70% of forward thrust. For the reversible type, two directions are optional and the thrust and airflow levels in two directions are relatively same.

Fan Stack

Quality steel sheets shall be used. Brackets shall be all welded so that they are strong to support the dynamic load.


Aluminum alloys of high strength shall be used for the hub and blades of the fan. Each blade must undergo X ray flaw detection for manufacturing reliability.

Lock bolts of high strength shall be adopted to fasten the airfoil blades with the hub. Dynamic balancing tests shall be conducted on each impeller. Blade pitches shall be available for adjustment for various operating conditions.


There shall be a double layer structure in cylindrical shape for the silencers. The super fine glass fiber is between the inner layer of perforated sheet and the outer layer of quality steel sheet. The glass fiber shall be of Class A fire rating and resistant to insects and damp-proof.

Surface Treatment

The surface shall be able to prevent corrosion and rust through proper treatment. At least two layers of base coat and finish coat shall be there to be resistant to high temperature. The galvanized process shall be performed on the surface to prevent corrosion in the long term.


Sealed type asynchronous squirrel cage motor that can prevent damp heat shall be mounted on the fan. It shall have a degree of protection standard IP55 and an insulation class H. For easy wiring, the lead wire is linked to the junction box; The lubrication line connecting with the grease nipple on the housing results in easy maintenance and lubrication.

Smoke Exhaust Certification

Tests shall be performed on the YFTNV jet fan according to GA211-2009 GA 211-2009 High Temperature-Resistant Test Methods for Smoke and Heat Exhaust Ventilators by and ensure the relevant requirements are met. The tests shall be done by a test agency assigned by China Certification Centre for Fire Products Ministry of Public Security. The fan shall be certified to run for at least 1 straight hour under 250℃.

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