• Active supply air unit for ceiling mounting • Stable supply throw length with variable airflow • Balancing plenum VRI/V with connection cable for VHB rates • Elimination of the risk of draughts • Wide supply air temperature range • Useful in systems with a constant static pressure ductwork system • Designed for use with the VRI/V plenum • Maximum flow rate adjustment and measurement section available for supply (MSM) • Minimum airflow of the VHB: approximately 10…15 l/s for sizes 160…250 MATERIAL PART Upper plate Powder painted, white RAL 9010 Front panel Perforated steel Powder painted, white RAL 9010 Control cone Powder painted, black

LpA values presented with room attenuation 4 dB (red 10m 2 sab). When using room attenuation 8 dB (red 25m 2 - sab): LpA - 4dB. Pa LpA DPst DPtot Total pressure drop, Pa Ld Distance from the supply unit, at which air jet detaches from ceiling, m Lmin Minimum distance between central lines of two supply units, m (V3 = 0,25m/s at 1.8m height) L0.2 Isotermal throw length, m when residual velocity of supply air jet 0,2 m/s Room temperature (Tr) = 24 °C Supply air temperature (Ta) 14 °C = Room height = 2,8 m Supply air cooling capacity, W A-weighted sound pressure level, reduced by total equivalent...

VRI/V plenum for supply air The VHB is an active ceiling diffuser for supply air. Use of the VHB is most beneficial with a VRI/V Air is supplied to the room space mainly through plenum. The VRI/V plenum includes: the side slots of the diffuser. The air jet supplied A measurement and adjustment module MSM horizontally through the side slots induces room air. An electric junction box for power and control signal The unit maintains a high outlet air velocity between supply as well as an cable for easy connection of the the minimum and maximum airflow rates, creating comfortable conditions and low...

Pressure drop, throw pattern and sound data Selection example:

SOUND LEVEL DATA 5 LpA values presented with room attenuation 4 dB (red 10m2 - sab). When using room attenuation 8 dB (red 25m2 - sab): LpA - 4dB. NR/NC noise criteria

Installation The active diffuser shall be installed in conjunction with the VRI/V plenum box. The VRI/V plenum shall have a safety distance of 3D minimum upstream, to ensure reliable measurement and accurate control of the airflow rate. A hanging and safety wire for VHB diffuser is delivered Wiring diagram with the VRI/V plenum. Hang the VHB diffuser to the wire by means of a key ring. VHB is connected electrically to VRI/V with ready assembled cable plug. Control that the actuator settings are in line with the factory pre-setted DIL switches. Release the actuator clutch and pull the control...

Make sure that the control cone of each active The airflow rate of the active diffuser is measured and VHD (and VHB) damper is fully open (at the lowest adjusted using the MSM module inside VRI/V plenum. position). This can be done either mechanically or Attach the measurement instrument to the measuring tubes on VRI/V plenum and the airflow rate is calculated using the pressure difference reading and If the power is not connected to active diffuser, release the actuator clutch and pull the control cone to NS If a 24 VAC power supply is connected to diffusers, please make sure that the control...