VENTS VKMI series

Application

The new inline VKMI fans are enclosed in a specially designed sound-insulated casing, which ensures silent operation in combination with high aerodynamic characteristics. The fans are compatible with round air ducts from Ø 100 up to 315 mm and produce maximum air flow 1880 m³/h.

The VENTS VKMI fans are featured with wide capabilities and high performance of both axial and centrifugal fans, thus providing powerful air stream and high pressure. The fans are recommended as a component of the air handling systems for various commercial and industrial premises with high requirements to noise level, i.e. libraries, conference halls, educational institutions, kindergartens, etc.

Design

The outer casing is made of polymer-coated steel. The inner casing perforation let sound waves pass through the holes and fall to the sound-absorbing layer at a specific angle. The casing is internally heat- and sound-insulated with 50 mm isover layer. The specially perforated casing and sound-absorbing material provide sound attenuation in a broad frequency band. The inner casing and the impeller are made of high-quality durable plastic. The intake spigot is equipped with a protection grille.

Motor

A centrifugal impeller with forward curved blades is powered by a single-phase external rotor motor. The motor is equipped with self-resetting overheating protection. Some standard sizes are available with a high-powered motor, see modification VKMI S.

The motor is equipped with ball bearings for a long service life designed for at least 40 000 operating hours. For precise features, safe operation and low noise, each impeller is dynamically balanced while assembly. Motor protection rating is IP 44.

Speed control

Smooth or step speed control with a thyristor or autotransformer speed controller. Several fans may be connected to one speed controller provided that the total power and operating current do not exceed the rated speed controller parameters.

Mounting

The fans are designed for inline mounting inside an air duct of matching air duct diameter, in any point of the ventilation system and at any angle.
The fan can be supplied with fixing brackets for fastening to the wall (K option).

The fan with electronic temperature and control module (U option)

The ideal solution for ventilation of the premises requiring permanent temperature control, i.e. greenhouses. The fan with the electronic temperature and speed control module provides automatic control of the motor speed (air capacity) depending on air temperature in the air duct or in the room.

The front panel of the electronic module has the following control knobs:

• speed control knob for setting the motor speed;
• thermostat control knob for setting the temperature set point;
• thermostat indicator light.

The fan is available in two modifications:

• with the temperature sensor integrated inside the fan air duct (U/U1 option);
• with the external temperature sensor fixed on the cable, 4 m long (Un / U1n).

Control logic of the fan with the electronic temperature and speed control module

Set the desired air temperature (thermostat set point) by turning the thermostat control knob. Set the required minimum impeller speed (air flow) by turning the speed control knob. The motor switches to maximum speed (maximum air flow) as the temperature reaches and exceeds the set temperature set point. The motor switches to the pre-set lower speed as the temperature drops down below the temperature set point. To avoid frequent motor speed switches when the air temperature in the duct is equal to the set temperature point, the speed switch delay is activated. There are two switch delay patterns for various cases:

1. The temperature sensor-based switch delay (U option): the motor switches to higher speed as the air temperature exceeds 2°C above the set thermostat set point. The motor revers to the pre-set lower speed as the air temperature drops below the thermostat set point. This pattern is used to keep air temperature to within 2°C. In this case the motor speed switches are rare.
2. The timer-based switch delay (U1 option): as the air temperature exceeds the set thermostat set point, the motor switches to higher speed and the switch delay timer is activated for 5 min. The motor reverts to lower speed as the air temperature drops down below the thermostat set point and only after 5 minuts timer countdown. This pattern is used for exact air temperature control. The speed switches for the fan with U1 option are more frequent as compared to the operating logic of the fan with U option, however the minimum operating cycle at one speed is 5 minutes.