RAVAV
The RAVAV regulator is designed for variable air flow ventilation systems and is an important component for optimizing of air flow into the indoor premises for energy savings.
The regulator casing is made of Z 275 galvanized sheet. Casing sides with factory-installed EPDM rubber gaskets ensure tight connection to ventilation ducts. Inside the casing, the adjusting damper is also insulated. The servomotor is installed on the control unit casing so as to allow for thermal insulation of the system.
The measuring system based on aluminum impact pressure tubes and pressure relieve stub pipes ensures reliable measuring of the air flow. Servomotor, control unit and sensor are integrated in one device. The servomotor adjusts the damper position, the control unit compares the current air flow rate with the set value and the sensor turns the differential pressure value into electric signal.
As a standard, the RAVAV control units are supplied with LMV-D3-MP (NMV-D3-MP) actuator. Optional actuator can be from Siemens or Gruner.
The insulation rating of the adjusting damper is class 4 as per EN-1751:1998.
Casing tightness is class C as per EN-1751:1998.
The actuator (a), a control unit (b) and sensor (c) are integrated into one device. The actuator adjusts the damper position, the control unit compares the current air flow rate with the set value and the sensor turns the differential pressure value into the electric signal.
Characteristics of the RAVAV volume regulator:
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high air flow measurement accuracy (also applies when the regulator is installed in locations with high disturbance in the air flow, e.g. duct sections behind bends, T-pieces, etv.)
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the insulation rating of the adjusting damper is class 4 as per EN-1751:1998,
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casing tightness is class B as per EN-1751:1998,
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operating temperature range from 0 to 50 [oC],
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differential pressure range from 0 to 600 [Pa],
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possibility to measure current air flow parameters using external,
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micromanometers.
At the design stage and during subsequent installation of VAV regulators, it is recommended to ensure that the longest possible straight duct section are placed before an after the regulator. This ensures the very high accuracy of air flow measurement. It is possible to supply the regulator with a flow straightener with normalized dimensions, allowing to balance the disrupted air flow. Observe the proper air flow direction through the regulator, as indicated on the product label.
Depending on the selected regulator control solution, the following configurations are possible:
a. constant setting (VAV) – air flow adjusted depending on a constant control signal 0...10 or 2…10 V,
b. forced setting (CAB) – air flow adjusted depending on a forced setting:
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damper position closed,
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damper position open,
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Vmin. position – maintaining a minimum air flow speed (e.g. due to hygiene requirements),
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Vmax. position – maximum airflow (quick change of air conditioning parameters for a particular zone/facility),
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Vaver. position – an intermediate position, value between Vmin. and Vmax.
c. digital control via MP bus (e.g. DDC regulator, adjusting fan operation, systems: LonWorks, EIB-Konnex, BACnet, MODBUS RTU).
It is also possible to deliver special automated solutions such as: short adjustment time, highly polluted environments, rooms with a specific requirement of under and overpressure.