VHD - VAV diffuser

Circular VAV diffuser for draught free installation

Exposed circular active diffuser for variable airflows, which works in constant pressure duct system.

  • Installation for suspended ceiling
  • Stable throw length with variable supply airflow rates
  • Wide supply air temperature range
  • Suitable for systems with 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 between10…15 l/s for sizes 160…250
  • airflow control with actuator, 24 VAC, signal 0-10V

 

ACCESSORIES

  • ·Balancing plenum VRI/V with connection cable

The active diffuser shall be made of painted steel with a white (RAL 9010) standard colour.
Air shall be introduced into the space through the side slots and perforated front panel, ensuring a high mixing rate. The diffuser shall maintain appropriate discharge velocity throughout the total airflow range.

The diffuser shall be connected to a balancing plenum designed for the active diffuser installation and equipped with a measurement and adjustment module.

The diffuser shall have a rubber gasket to ensure tight connection to the plenum.

Introduction

Halton VHD

Active round ceiling diffuser



 

  • Installation for suspended ceiling
  • Stable throw length with variable supply airflow rates
  • Wide supply air temperature range
  • Suitable for systems with constant static pressure ductwork system
  • Designed for use with the Halton VRI/V plenum
  • Maximum flow rate adjustment and measurement section available for supply (MSM)
  • Minimum airflow between 10…15 l/s for sizes 160…250

Accessories

  • Balancing plenum Halton VRI/V with connection cable
     

Dimensions

Dimensions


Halton VHD


 

NS ØW H H1 ØD
160 299 234 98 159
200 449 267 104 199
250 449 275 116 249


Halton VHD with Halton VRI/V plenum


 

NS VRI/V L L1 H H1 K ØD ØD1
160 160...160 458 299 222 96...126 432 159 162
200 200...200 618 449 272 100...130 592 199 202
250 250...250 618 449 336 111...141 592 249 252


Material

Material


Halton VHD

 Part  Material  Finishing
 Upper plate  Steel  Powder painted, white RAL 9010
 Front panel  Perforated steel  Powder painted, white RAL 9010
 Control cone  Steel  Powder painted, black
 Gasket  Rubber  

Accessories

Accessories


Halton VHD
 

In the standard delivery the Halton VHD is always equipped with a Siemens GDB161.2E/HA damper actuator.
 

 Actuator  Force  Control
 signal
 Operating
 voltage
 Power
 consuption
 GDB161.2E/HA  125 Nm  0...10 VDC  24 VAC  3VA


Function

Function


Halton VHD



The Halton VHD is an active ceiling diffuser for supply air.

Air is supplied to the room space mainly through the side slots of the diffuser. The air jet supplied horizontally through the side slots induces room air.
The unit maintains a high outlet air velocity between the minimum and maximum airflow rates, creating comfortable conditions and low residual air velocities in the occupied zone.

In the demand-based ventilation (DBV) and variable air volume (VAV) systems, room conditions can be guaranteed to be without a risk of draughts, at both the maximum and minimum airflow rate.
The pressure dependent function of the Halton VHD operates in combination with a constant pressure duct zone.
An external room controller varies the room airflow rate by running the Halton VHD diffuser actuator with a standard 0…10 VDC control signal.
 

Related Products

Related products


Halton VHD 



Use of the Halton VHD is most beneficial with a Halton VRI/V plenum. The Halton VRI/V plenum includes:

  • A measurement and adjustment module MSM
  • An electric junction box for power and control signal supply as well as an cable for easy connection of the variable air diffuser Halton VHD
  • Installation safety and hanging wire for air diffuser

Installation

Installation


Halton VHD




The active diffuser shall be installed in conjunction with the Halton VRI/V plenum box. The Halton 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 Halton VHD diffuser is delivered with the Halton VRI/V plenum. Hang the Halton VHD diffuser to the wire by means of a key ring.

Halton VHD is connected electrically to Halton 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 cone to the fully open position.

Mount the Halton VHD diffuser assembly to the Halton VRI/V plenum box.

Note:
The technical performance for the combination of supply air diffuser and plenum is presented separately for the two different installations.

 

Dimensions of installation hole in suspended ceiling
 


 

NS ØD2
160 211
200 265
250 333


Wiring

Wiring


Halton VHD

 

Wiring diagram


Junction box                                                              Cable connection plug

 

Control signals on junction box

Terminal 3

  • 0 VDC  = minimum position / airflow
     
  • 10 VDC  = maximum position / airflow
     

Terminal 4 (feedback from actuator)

  • Not connected
     

Commissioning

Commissioning


Halton VHD




Make sure that the control cone of each active Halton VHD (and Halton VHB) damper is fully open (at the lowest position). This can be done either mechanically or electrically:
 

  • If the power is not connected to active diffuser, release the actuator clutch and pull the control cone to the fully open position.
  • If a 24 VAC power supply is connected to diffusers, please make sure that the control signal is constantly at 10 VDC.

Check that the duct zone constant pressure is at the intended level (for example, between 30 and 50 Pa).

If the duct zone pressure is too low and the zone pressure control damper is fully open, you should either adjust the supply fan pressure setpoint to be higher or adjust the MSM adjustment unit in the VRI/V plenum.

The zone pressure control damper shall have a sufficient operative differential pressure over the damper (for example, 30 Pa or more).
 

Adjustment

The airflow rate of the active diffuser is measured and adjusted using the MSM module inside Halton VRI/V plenum.

Attach the measurement instrument to the measuring tubes on Halton VRI/V plenum and the airflow rate is calculated using the pressure difference reading and the k factor.

      

qv          Calculated airflow rate [l/s]
           k factor from the table
Δpm      Measured pressure [Pa]
 

NS k factor
160 15.9
200 26.2
250 44.5

 

If the airflow rate of the active diffuser is too high, adjust the position of the MSM adjustment unit in the Halton VRI/V plenum to closer position. If maximum airflow can't be reached, open MSM module first full open and if this is not enought, increase the duct zone pressure

The minimum airflow is factory pre-adjusted. 

Servicing


SERVICING

Open the diffuser part and detach the perforated plate of the coupling sleeve. Remove the control cone part completely.

Loosen two screws which are holding the motor assembly on VHD body and let it hang on the wire.

The MSM is removed through VRI/V outlet by pulling from it's body - not the measurement tubes or control spindle.

Clean the parts with a damp cloth, instead of immersing in water.

Replace all parts in opposite order.

Technical specification text

Technical specification text

 

The active diffuser shall be made of painted steel with a white (RAL 9010) standard colour.
Air shall be introduced into the space through the side slots and perforated front panel, ensuring a high mixing rate. The diffuser shall maintain appropriate discharge velocity throughout the total airflow range.

The diffuser shall be connected to a balancing plenum designed for the active diffuser installation and equipped with a measurement and adjustment module.

The diffuser shall have a rubber gasket to ensure tight connection to the plenum.

Product Code

Product code


VHD-D

D = Connection size
 
    160, 200, 250
 


Other options and accessories

CO = Colour
      
   W     White (RAL 9010)
         X      Special colour
 

ZT= Tailored product
         N       No

 

Sub products

         VRI/V Plenum

 

 

Code example

           VHD-160, CO=W


 

Downloads & Media

Halton VHD - gb
Type
Datasheet
Taal
Engels (Verenigd Koninkrijk)
Grote
898,0 kB
Halton VHD - nl
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Nederlands (Nederland)
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Halton VHD - fi
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Fins (Finland)
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898,9 kB
Halton VHD - ru
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Russisch (Rusland)
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Halton VHD - se
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Zweeds (Zweden)
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898,3 kB
Halton VHD - fr
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Datasheet
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Frans (Frankrijk)
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