Function
The VAV terminal unit is fitted with an effective pressure sensor for measuring the volume flow rate.
The control components (attachments) include an effective pressure transducer that transforms the effective pressure into an electric signal, a controller, and an actuator; the control functions can be achieved with an Easy controller or with a Compact controller or with individual components (Universal or LABCONTROL).
For most applications, the setpoint value comes from a room temperature controller.
The controller compares the actual value with the setpoint value and alters the control signal of the actuator if there is a difference between the two values.
An integral attenuator reduces the noise that is created by the restriction of the airflow.
The airflow velocity at the room end is, due to the larger rectangular cross section, about half the velocity in the circular duct.
Schematic Illustration of the TVZ

1 Differential pressure sensor
2 Double lip seal
3 Inspection access
4 Damper blade
5 Integrated silencer
6 Control components, e.g. Easy controller
Specification Text
This specification text describes just one variant of the product and is suitable for many applications. Texts for other variants can be generated with our Easy Product Finder design program.
Specification text
Rectangular VAV terminal units for variable and constant air volume systems, suitable for supply air, available in 6 nominal sizes. High control accuracy (even with upstream bend R = 1D).
Ready-to-commission unit which consists of the mechanical parts and the electronic control components. Each unit contains an averaging effective pressure sensor for volume flow rate measurement, a damper blade, and an integral sound attenuator. Factory-assembled control components complete with wiring and tubing. Effective pressure sensor with 0.1 in measuring holes, hence resistant to contamination. Baffle plate is fitted after the damper blade for optimum acoustic and aerodynamic performance. Casing with acoustic and thermal insulation. Position of the damper blade indicated externally at shaft extension. The damper blade is factory set to open position, which allows a ventilation airflow even without control; this does not apply to variants with defined safe position NC
(normally closed). Meets the hygiene requirements of EN 16798, Part 3, of VDI 6022, Sheet 1, and of DIN 1946, Part 4.
Special features
- Integral attenuator with at least 26 dB insertion loss at 250 Hz
- Hygiene tested and certified
- Factory set-up or programming and aerodynamic function testing
- Parameters can also later be set on the control component; additional adjustment device may be necessary
- Inspection access according to VDI 6022
Materials and surfaces
- Casing and damper blade made of galvanised sheet steel
- Damper blade seal made of TPE plastic
- Lining made of mineral wool
- Differential pressure sensor made of aluminium
- Plastic plain bearings
- Shaft and linkage: galvanised steel
Mineral wool:
- According to EN 13501, fire rating class A1, non-flammable
- RAL quality mark RAL-GZ 388
- Non-hazardous to health due to high biosolubility according to the German Hazardous Substance Ordinance and Note
- Q of European Regulation (EC) No. 1272/2008
- Faced with glass fibre fabric as protection against erosion from airflow velocities of up to 20 m/s
- Inert to fungal and bacterial growth
Connection type
- Spigot with groove for double lip seal on the fan end, suitable for connecting ducts according to EN 1506 or EN 13180. Room end suitable for the connection of ducts.
Equivalence criteria
- Declaration of hygiene conformity in accordance with VDI 6022, Part 1 (01/2018), ÖNORM H 6020 (02/2007) and ÖNORM H 6021 (09/2003)
- Meets the hygiene requirements according to EN 16798 Part 3, VDI 6022 Sheet 1, DIN 1946 Part 4
- Acoustic data to ÖNORM EN ISO 5135:1999
- Setting the volume flow without adjustment device via Vmin and Vmax potentiometers
- Electrical connections with screw terminals, no additional terminal box required
- The test report of the factory parameterisation, functional test and adjustment under air by reference measurement on a regularly validated test rig in accordance with DIN EN ISO 9001 is made available
Technical data
- Nominal sizes: 5 to 16″
- Volume flow rate range: 30 – 3394 cfm
- Minimum differential pressure: up to 0.49 in WG (without secondary silencer)
- Maximum differential pressure: 4.02 in WG
- Closed blade air leakage to EN 1751, class 4 (nominal sizes 5 and 6, class 3).
- Casing air leakage to EN 1751, class 4 (nominal size 10, 12, 416, class B)
Specification text attachment
Variable volume flow control with electronic Easy controller to connect an external control signal; actual value signal can be integrated into the central BMS.
- Supply voltage 24 V AC/DC
- Signal voltages 0 – 10 V DC
- Possible override controls with external switches using volt-free contacts: CLOSED, OPEN, qᵥmin and qᵥmax
- Potentiometers with percentage scales to set the volume flow rates qᵥmin and qᵥmax without an adjustment device
- The actual value signal relates to the nominal volume flow rate such that commissioning and subsequent adjustment are simplified
- Volume flow rate control range: approx. 10 – 100 % of the nominal volume flow rate
- Clearly visible external indicator light for signalling the functions: Set, not set, and power failure
- Electrical connections with screw terminals
- Double terminals for looping the supply voltage, i.e. for the simple connection of voltage transmission to the next controller