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  • Description
  • Characteristics
  • Downloads
  • Modifications
  • Dimensions
  • Additional diagrams
  • Dimensions
  • Designation key
  • Accessories
  • Operation of fans with frequency converters
  • The fans are used:
    • as a part of a smoke extraction system for air pressurization to create a positive air pressure differential in stairway enclosures, airlock vestibules and lift shafts, to prevent spreading of smoke in premises, protect people using evacuation routes from fire hazards and enable conditions for fire-extinguishing measures.
    • in general ventilation systems in industrial, administrative and residential buildings.
  • Depending on the size and the required air capacity the fans are equipped with impellers with 6 or 8 blades angled from 20° to 50° with variation from 2.5 up to 5° to ensure precise matching of fans with the operating point.
  • The specially designed impeller blades ensure high efficiency of the fan while keeping noise well under control.
  • The impellers are dynamically balanced.
  • Low weight and low moment of the impeller inertia help reduce the fan start-up time.
  • The fan blades can be made of the following materials:
    • PAG - fiberglass reinforced polyamide;
    • AL - aluminium.
  • Please confirm the blade material while placing your order.
  • The metal casing with rolled flanges helps achieve outstanding rigidity and minimum clearances between the casing and the blades.
  • There is an inspection hatch in the casing for easy maintenance.
  • All the casing components are powder coated for improved protection against the environmental effects.
  • The weight of the fans may differ from the one stated in the catalogue and depends on the components used (motor, terminal box, etc.).
  • The fans are equipped with three-phase (400 V/50 Hz) single-speed 2-, 4- or 6-pole electric motors.
  • Motor with energy efficiency class IE3 on request.
  • The fans can be mounted on any flat surface or directly into a ventilation duct.
  • The units are suitable for both horizontal and vertical configurations.
  • In-duct installation requires flanges to attach the fan to the ductwork.
  • To attach the fan to the floor, a wall or the ceiling use the O-VO carriers (not included as standard, should be purchased separately).
  • The units are suitable for installation on rooftops to provide direct supply of outdoor air to the stairway areas.

Fan installation with no upstream ducting

  • Axial fans without upstream ducting must be equipped with the VK-VO inlet cone to improve the air flow parameters.

Fan installation into an air duct system:

  • To ensure a uniform air flow the fan should be preceded by a straight duct section with a cross-section area equal to half of that of the fan.
  • The length of the duct section should be 3 ÷ 4 D (D is the inner diameter of the fan).
  • The length of the straight duct section downstream of the fan should be 1.5 ÷ 2 D.
  • Reduction of the recommended duct length values results in a drop of the fan pressure and performance.
  • To reduce noise and vibration use the VVGF flexible joints.

Fan installation with no downstream ducting:

  • If the axial fan is a terminal device of the ventilation system (i.e. there is no downstream ducting) the unit must be equipped with a diffuser to reduce the air flow velocity and the fan dynamic pressure.
  • Reduction of the air discharge velocity results in a significant reduction of shock losses which are proportional to the square of velocity decrement.
  • The fan should not be equipped with a downstream contractor.


Installation near bends:

  • To install the fan directly downstream of a bend (elbow) use a curved section with a large bending radius or an array of internal guide vanes.

Changing diameter installation:

When changing from a smaller diameter to a larger one use a connector diffuser with the maximum opening angle of 12°.

Obstructed space installation:

  • To ensure normal operation of the fan in an obstructed space make sure to provide for a sufficient distance between the inlet and outlet flanges and the floor, walls, bulky equipment and obstacles.

Parameter VPVO-450-2D/0,75-6/25/PAG
Measurement unit
Size 450 450 450 450 450 450 -
Smoke removal yes yes yes yes yes yes -
Design round flange, axial round flange, axial round flange, axial round flange, axial round flange, axial round flange, axial -
Pole number 2 2 2 2 2 2 -
Phase 3 3 3 3 3 3 ˜
Voltage 400 400 400 400 400 400 V
Frequency 50 50 50 50 50 50 Hz
Installed power capacity Ny 0.75 1.1 1.5 2.2 3 4 kW
RPM 2880 2880 2880 2880 2880 2880 min-1
EC motor no no no no no no -
Quantity of blades 6 6 6 6 8 8 -
Blade setting angle 25 30 35 40 40 45 °
Casing material painted steel painted steel painted steel painted steel painted steel painted steel -
Length 350, 450 (IE3) 450 450 450 450, 550 (IE3) 550 mm
Mass 36.1 36.6 42.1 44.1 53.6 63.7 kg
Outdoor mounting yes yes yes yes yes yes -
Sound-insulated casing no no no no no no -
Duct for round air ducts for round air ducts for round air ducts for round air ducts for round air ducts for round air ducts -
Mounting floor mounting, wall mounting, ceiling mounting, for roof, Inline floor mounting, wall mounting, ceiling mounting, for roof, Inline floor mounting, wall mounting, ceiling mounting, for roof, Inline floor mounting, wall mounting, ceiling mounting, for roof, Inline floor mounting, wall mounting, ceiling mounting, for roof, Inline floor mounting, wall mounting, ceiling mounting, for roof, Inline -
Files archieve
Brochure "Medium pressure axial fans VENTS VPVO" (pdf 3.93Mb)
Catalogue "Axial fans VPVO. Axial smoke extraction fans VDO" (pdf 12.4Mb)
Download high quality image "VENTS VPVO" (psd 4.04Mb)
Download image "VENTS VPVO" for your website (png 325.12Kb)
User's manual "VENTS VPVO" (pdf 2.7Mb)
Modification name
Parameter Value Measurement unit
Additional diagrams
Additional diagrams
Curve number on graph Fan model with aluminum blades impeller (AL) Fans model with fiberglass reinforced polyamide blades impeller (PAG)
1 - VPVO-450-2D/0,75-6/25/PAG
2 VPVO-450-2D/1,1-6/30/AL VPVO-450-2D/1,1-6/30/PAG
3 VPVO-450-2D/1,5-6/35/AL VPVO-450-2D/1,5-6/35/PAG
4 VPVO-450-2D/2,2-6/40/AL VPVO-450-2D/2,2-6/40/PAG
5 VPVO-450-2D/3-8/40/AL VPVO-450-2D/3-8/40/PAG
6 VPVO-450-2D/4-8/45/AL VPVO-450-2D/4-8/45/PAG

Designation key
Designation key

Fan Ø 400 Ø 450 Ø 500 Ø 560 Ø 630 Ø 710 Ø 800 Ø 900 Ø 1000 Ø 1120 Ø 1250
Carrier O-VO-400 O-VO-450 O-VO-500 O-VO-560 O-VO-630 O-VO-710 O-VO-800 O-VO-900 O-VO-1000 O-VO-1120 O-VO-1250
Flange F-VO-400 F-VO-450 F-VO-500 F-VO-560 F-VO-630 F-VO-710 F-VO-800 F-VO-900 F-VO-1000 F-VO-1120 F-VO-1250
Flexible joint VVGF-VO-400 VVGF-VO-450 VVGF-VO-500 VVGF-VO-560 VVGF-VO-630 VVGF-VO-710 VVGF-VO-800 VVGF-VO-900 VVGF-VO-1000 VVGF-VO-1120 VVGF-VO-1250
Flexible joint up to 400 °С VVGF-VO-400 - 400/2 VVGF-VO-450 - 400/2 VVGF-VO-500 - 400/2 VVGF-VO-560 - 400/2 VVGF-VO-630 - 400/2 VVGF-VO-710 - 400/2 VVGF-VO-800 - 400/2 VVGF-VO-900 - 400/2 VVGF-VO-1000 - 400/2 VVGF-VO-1120 - 400/2 VVGF-VO-1250 - 400/2
Hood Z-VO-400 Z-VO-450 Z-VO-500 Z-VO-560 Z-VO-630 Z-VO-710 Z-VO-800 Z-VO-900 Z-VO-1000 Z-VO-1120 Z-VO-1250
Roof adapter PK-VO-400 PK-VO-450 PK-VO-500 PK-VO-560 PK-VO-630 PK-VO-710 PK-VO-800 PK-VO-900 PK-VO-1000 PK-VO-1120 PK-VO-1250
Mounting curb SM-VO-400-450 SM-VO-500 SM-VO-560-630 SM-VO-710-800 SM-VO-900 SM-VO-1000-1120 SM-VO-1250
Inlet cone VK-VO-400 VK-VO-450 VK-VO-500 VK-VO-560 VK-VO-630 VK-VO-710 VK-VO-800 VK-VO-900 VK-VO-1000 VK-VO-1120 VK-VO-1250
Backdraft damper КОМ-VО-400
Backdraft damper КОМ1-VО-400 КОМ1-VО-450 КОМ1-VО-500 КОМ1-VО-560 КОМ1-VО-630 КОМ1-VО-710 КОМ1-VО-800 КОМ1-VО-900 КОМ1-VО-1000 КОМ1-VО-1120 КОМ1-VО-1250
Silencer SR-400-1D SR-450-1D SR-500-1D SR-560-1D SR-630-1D SR-710-1D SR-800-1D SR-900-1D SR-1000-1D SR-1120-1D SR-1250-1D
SR-400-1.5D SR-450-1.5D SR-500-1.5D SR-560-1.5D SR-630-1.5D SR-710-1.5D SR-800-1.5D SR-900-1.5D SR-1000-1.5D SR-1120-1.5D SR-1250-1.5D
SR-400-2D SR-450-2D SR-500-2D SR-560-2D SR-630-2D SR-710-2D SR-800-2D SR-900-2D SR-1000-2D SR-1120-2D SR-1250-2D
Silencer SRV-400-1D SRV-450-1D SRV-500-1D SRV-560-1D SRV-630-1D SRV-710-1D SRV-800-1D SRV-900-1D SRV-1000-1D SRV-1120-1D SRV-1250-1D
SRV-400-1.5D SRV-450-1.5D SRV-500-1.5D SRV-560-1.5D SRV-630-1.5D SRV-710-1.5D SRV-800-1.5D SRV-900-1.5D SRV-1000-1.5D SRV-1120-1.5D SRV-1250-1.5D
SRV-400-2D SRV-450-2D SRV-500-2D SRV-560-2D SRV-630-2D SRV-710-2D SRV-800-2D SRV-900-2D SRV-1000-2D SRV-1120-2D SRV-1250-2D
Protective mesh SZ-VO-400 SZ-VO-450 SZ-VO-500 SZ-VO-560 SZ-VO-630 SZ-VO-710 SZ-VO-800 SZ-VO-900 SZ-VO-1000 SZ-VO-1120 SZ-VO-1250
Spring-loaded antivibration mount  VVCp*
Rubber antivibration mount VVCr*

* selection according to the fan weight

Operation of fans with frequency converters
Operation of fans with frequency converters
  • Ventilation systems produce a heavy load on the electrical systems of a building.
  • Therefore, reducing the power consumption is among the top priorities for construction project designers.
  • As a rule, smoke extraction systems utilize large high-performance fans. During starting the high inertia of the shaft causes a substantial increase in the start-up time - i.e. the time from the application of power to reaching the rated speed. As a result the motor is subjected to high starting current for a prolonged period of time.
Current diagram with direct on-line starting
  • Standard switchgear (automatic circuit breakers, contactors and motor starters) is not designed to withstand prolonged overloads causing the fan to shut down automatically during starting.
  • Using switchgear with a higher maximum current rating renders the electric motor protection system less sensitive.
  • As a result the switchgear will not be able to detect motor overload in time due to a higher current sensing threshold.
  • Such challenges can only be addressed by utilizing a soft starter or a frequency converter to start the fan without causing a prolonged overload.
Torque diagram with direct on-line starting
  • A frequency converter (FC) consists of two main component blocks. One converts alternating current (50 or 60 Hz) into direct current.
  • The other converts direct current into alternating current of variable frequency ranging from 0 to 250 Hz.
  • By controlling the frequency output the FC offers a broad range of motor speed regulation.
Current diagram with FC starting
  • During the starting the FC raises the frequency from 0 Hz to the electrical mains frequency (50 or 60 Hz).
  • As the frequency is increased gradually, the motor can be assumed to operate at its nominal speed for a given frequency value.
  • Furthermore, on the assumption that the motor runs at its nominal speed the nominal torque should be immediately available whereas the current will be approximately equal to the nominal value.
Torque diagram with FC starting
  • Unlike an FC, a soft starter does not change the frequency of speed.
  • Instead it gradually increases the voltage supplied to the motor - from the initial level to the nominal level.
Current diagram with soft starter


Torque diagram with soft starter
  • The very low voltage initially supplied to the motor during starting helps avoid sudden jolts.
  • Both voltage and torque increase gradually.
  • Using an FC or a soft starter allows to reduce the starting current thereby avoiding a loss of voltage in the electrical mains.
  • In addition to that the starting torque and mechanical strain on equipment are also reduced which translates into extended maintenance and repair intervals.
  • General exhaust ventilation (GV) systems and emergency smoke extraction (SE) systems of car parks, warehouses, utility and industrial spaces can be integrated into a single system at the design level.
  • As the air flow rate a GV system is considerably lower than that in an SE system a high-capacity fan rated for smoke extraction duty runs in partial load mode.
  • Frequency converters can be programmed for several fixed-speed settings to enable operation in GV and SE modes.
  • The fan operating modes can be switched upon receiving an external signal from the control system.
  • Such integration of ventilation systems allows overall cost savings.


  • Below you can find two series of frequency converters: FC-51 and FC-101.
  • The FC-51 series is only suitable for general ventilation systems.
  • If intended for a smoke extraction system, the fans should be fitted with the FC-101 series units as they feature an integrated fire mode.
  • When activated the integrated protection equipment of the frequency converter is overridden enabling the unit to continue operation despite the possibility of sustaining irreparable damage due to overheating or overloading.
  • In case of a fire, the FC-101 series frequency converters are capable of maintaining a higher air pressure level at landings compared to other areas of the building in order to keep the landings smoke-free.
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