VENTS PA…W series supply units

Description

The PA unit is a ready to use ventilation unit for air filtration, warming and supply to the room.

Casing

Steel casing covered with aluzinc coating internally filled with 50 mm heat- and sound-insulating layer made of mineral wool.

Filter

Integrated panel G4 filter ensures sufficient supply air purification (optionally F7).

Heater

The PA units are equipped with water heater. Depending on the required heating capacity the water heaters are available in two-, three- or four-row modifications. The water heaters are designed for max. operating pressure 1.0 MPa (10 bar) and max. operating temperature 95 °C of the heat medium.

Fan

The unit is equipped with a direct-driven centrifugal fan with backward curved blades and external rotor motor. The fan configuration ensures the best operating characteristics: high air capacity and efficiency combined with low noise level.

Mounting

The unit is designed for indoor installation either on the floor, on the wall or under the ceiling by means of a seat angle with inserted vibration-damping element or attached to a wall with brackets. The unit can be mounted either in service spaces or in main premises above the suspended ceiling, in the pocket or the unit can be placed directly in the room. All the electrical connections are performed through the terminal box placed in the connection box. PA supply units are supplied with the fastening brackets to facilitate mounting. Access for the unit maintenance and filter cleaning shall be provided. The unit design enables to lead the water heater pipes to the right or to the left while mounting. The pipes are directed on the right on supply air side by default.

Control and automation

The supply units are available in two modifications:

1. No control system. Customer-defined and customer-selected automation system.
2. Integrated control and automation system for speed (air capacity) control and setting supply air temperature. The unit may be remotely controlled from the external control panel fixed on wire.

PA…W control and protection functions

• control from the control panel: switching the unit on/off, fan speed selection (low/medium/high speed), selecting heating/cooling modes (if connected to duct cooler);
• maintaining supply air temperature set from the control panel by controlling the circulation pump and actuating the heat medium regulating valve; input from the heat medium flow switch (pump alarm);
• safe start-up/ shutdown of the fans, warming up of the water heater before start-up; return heat medium temperature control when the fan is off;
• freezing protection of the water heating coils by the exhaust temperature sensor and the return heat medium temperature sensor;
• control of the compressor and condensing unit of the water cooler by the room temperature sensor (for the models equipped with a duct air cooler);
• filter clogging degree with differential pressure sensor;
• actuating the external air damper with a return spring;
• unit shut down at signal from the fire alarm system.

Accessories to supply units:

SFK

Supplementary equipment

The mixing units USWK are recommended for smooth supply air temperature regulation in the units equipped with water heaters. The mixing unit USWK with three-way heat medium regulating valve and circulation pump provides smooth heating capacity regulation and minimizes the water heater freezing danger. To disable uncontrollable air flow when the fan is off it is recommended to install the air damper with servo actuator from outside at the unit inlet. To protect the water heater against cold intake air in case of power failure for the units with water heaters it is recommended to install the air damper with a return spring. For attenuation of sound generated by the fan it is recommended to install the duct silencer (refer SR). For vibration absorbing it is recommended to install the flexible anti-vibration connectors (refer VVG) on both sides of the unit.