galvanised round VAV damper with Gruner controller actuator

Variable Air Volume damper VAV diameter 250 mm

Product description

Galvanised round VAV unit diameter 250mm with low resistance damper blade, supplied with an adjustable electronic actuator and aluminium differential pressure sensor. This VAV unit can be applied for regulating constant or variable air volumes based on air quality and/or temperature. The damper blade is equipped with an air tight seal and maintenance free bearings. The laser welded housing meets Class C following EN 12237, damper blade meets Class 2 following EN 1751.
Manufacturer's ID
250 Mm
Adjustable motor

Additional specifications and description

The Variable Air Volume damper, also known as Variable Air Volume Regulator is designed for use with regular round or Spiro ducts as part of a VAV HVAC system. Thanks to the rubber seals, this product achieves an air tightness class C, according to EN 12237 and the damper blade meets leakage class 2 as per EN 1751. The device can operate in an air velocity range of between 0,8 m/s to 12 m/s and a temperature range of 0 to +50 °C and has an IP 42 protection rating. The integrated controller can operate without the need for external equipment.

Variable Air Volume dampers or VAV dampers are utilised in Variable Air Volume HVAC systems. This type of ventilation system is an evolution of the older style of Constant Air Volume (CAV) systems. The VAV systems maintain a constant temperature and vary the volume of air being pumped. In contrast, CAV systems regulate the air temperature while maintaining a constant volume of supplied air. The VAV approach offers better energy efficiency and can lead to a lower long-term operating cost for the system, despite the higher initial investment. Unlike CAV dampers, VAV dampers require external power, and depending on the design, they might also require external control to operate the actuator mechanism. VAV regulators allow the different rooms in a building to have more precise temperature control, as depending on the input from the thermostat or BMS (building management system), the damper can adjust the airflow accordingly. Thanks to their fine grain adjustment, flexibility, and energy efficiency, VAV HVAC systems continue to gain popularity, and VAV dampers are the cornerstone of these sophisticated systems. 

Construction and installation method:
This VAV damper housing is constructed out of laser-welded galvanised steel that offers good corrosion resistance. The smooth inner surface and thin metal blade help minimise airflow obstruction and noise generation. The differential air pressure sensor is made out of extruded aluminium. The actuator bearings are airtight and maintenance-free. Thanks to the use of EPDM rubber seals this damper achieves an air tightness class C, according to EN 12237 and the damper blade meets leakage class 2 as per EN 1751. The device offers very precise control with a measurement error of under 5% as measured according to ISO 3966. Note that to achieve the most accurate results the air velocity has to be over 1,2 m/s. When mounting the damper after a T-piece or a bend, it is recommended, to add a length of duct equal to 2 times the duct diameter has to be placed between the ventilation element and the VAV damper. The damper is equipped with the Grada G1: 227VM compact volume flow controller with display and integrated control, which can function autonomously. The operating voltage is 24 VAC/VDC, and the input and output signal lines work within a 2 - 10 V range.
 The full technical specifications and installation instructions can be found in the manufacturer’s datasheet, which you can download from this page.
Please note that the final airtightness of the ventilation system depends on several factors, including the installation method.