Description
For the most diverse application at standard volume flow with demanding acoustic requirements.
VAV terminal units for standard applications of supply air or extract air control in variable air volume systems with demanding acoustic requirements.
- Suitable for the control of volume flow rate, room pressure or duct pressure
- Electronic control components for different applications (Easy, Compact, Universal)
- Accurate air flow control even with upstream radius bend (R = 1D)
- Suitable for air velocities up to 13 m/s
- Operation pressure 20 to 1000 Pa
- Closed blade air leakage to EN 1751, Class 2 (size 4 – 10), Class 3 (size 12,14,16)
- Integral attenuator
- Box style construction for the reduction of the airflow velocity
- Tested and certified to AHRI Standard 880-2017
Application
- VAV terminal units of Type TVB for supply air or extract air flow control in variable air volume systems
- Closed-loop volume flow control using an external power supply
- Integral attenuator for demanding acoustic requirements
- Shut-off by means of switching (equipment supplied by others)
Variants
- TVB-A: VAV terminal unit
- TVB-B: VAV terminal unit with extended casing for better acoustics performance
- TVB-C: VAV terminal unit with multiple outlets
- TVB-E: VAV terminal unit with electric reheat unit
- TVB-EC: VAV terminal unit with multiple outlets and reheat unit
Nominal sizes
- 4, 5, 6, 7, 8, 10, 12, 14, 16
Attachments
- Easy controller: Compact unit consisting of controller with potentiometers, differential pressure transducer and actuator
- Compact controller: Compact unit consisting of controller, differential pressure transducer and actuator
- Universal controller: Controller, differential pressure transducer and actuators for special applications
Construction features
- Rectangular casing
- Spigot on the inlet suitable for circular ducts to DW144, 1998
- Connection on the room end suitable for air duct profiles
- Position of the damper blade indicated externally at shaft extension
- Thermal and acoustic insulation (lining)
Materials and surfaces
- Casing and damper blade made of galvanized sheet steel
- Damper blade seal made of Chloroprene rubber
- Lining is fiber glass
- Differential pressure sensor made of aluminum
- Plastic bearings Mineral wool
- Internal fiber glass insulation lining.
- Faced with woven glass fabric as protection against fiber erosion for airflow velocities up to 20 m/s
- Resistant to fungal and bacterial growth
Installation and commissioning
- Any installation orientation (except units with static differential pressure transducer)
- Return edges of the casing with drilled holes suitable for M8 threaded rods
Standards and guidelines
- Closed blade air leakage to EN 1751, Class 2 (4 – 10), Class 3 (12, 14, 16)
Maintenance
- Maintenance-free as construction and materials are not subject to wear
Useful additions
- Hot water heat exchanger
- Electrical heater
Special characteristics
- Factory set-up or programming and aerodynamic function testing
- Volume flow rate can later be measured and adjusted on site; additional adjustment device may be necessary
Parts and characteristics
- Ready-to-commission unit which consists of mechanical parts and control components
- Averaging differential pressure sensor for volume flow rate measurement
- Damper blade
- Integral attenuator
- Factory assembled control components complete with wiring and tubing
- Aerodynamic functional testing on a special test rig prior to shipping of each unit
- Set-up data is given on a label or volume flow rate scale affixed to the unit
Functional description
The VAV terminal unit is fitted with a differential pressure sensor for measuring the volume flow rate. The control components (attachments) include a differential pressure transducer that transforms the differential pressure (effective pressure) into an electric signal, a controller, and an actuator; the control functions can be achieved with an Easy controller, with a Compact controller, or with individual components.
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.