HFD - Mixing CAV and VAV unit for dual duct systems

Circular mixing VAV and CAV box for dual duct systems with fast commissioning due to factory-set airflow limits (min./max. airflow rates).

Pressure-independent operation. Tight shut-off operation at closed damper position. Ideal for renovation projects.

 

 

 

  • Control damper for variable and constant airflow control applications in dual duct systems
  • Pressure-independent operation
  • Galvanized steel construction with insulation
  • Tight shut-off operation at closed damper position
  • Circular duct connection equipped with rubber gaskets
  • Factory-set airflow range limits (min./max. airflow rates)

Product Models & Accessories

  • Additional insulation option
  • Sound attenuator
  • Different outlet plenum options

The dual duct mixing unit shall be made of galvanised steel with airflow measurement probes of aluminium.
Duct connections D = 100…500 mm shall include airtight neoprene or EPDM rubber gaskets. Damper blades shall include rubber gaskets.

The dual duct unit shall comprise airflow measurements, flow controllers and damper actuators. Design airflow range limits shall be calibrated at the factory.

The casing shall be acoustically insulated with 25-mm-thick mineral wool to avoid airborne noise emission into the duct and radiation of noise through the damper casing. When specified, unit design shall have additional external insulation containing 40 mm of acoustic material and a galvanised steel cover applied over the standard casing.

The dual duct unit shall be equipped with a sound attenuator in order to meet the sound level requirement for the room. As an option, the sound attenuator shall contain a central baffle.

Introduction


HFD

Airflow Management Damper for Dual Duct Systems



  • Control damper for variable and constant airflow control applications in dual duct systems

  • Pressure-independent operation

  • Galvanised steel construction with insulation

  • Tight shut-off operation at closed damper position

  • Circular duct connection equipped with rubber gaskets

  • Factory-set airflow range limits (min./max. airflow rates)


Product Models & Accessories

  • Additional insulation option

  • Sound attenuator

  • Different outlet plenum options


Dimensions


DIMENSIONS




HFD/S, mm

NS  L  L1  L2  W  W1  H  ØD  ØD1 
125  720 600 285 486 330 225 125 100
160  720 600 285 486 330 260 160 125
200  720 600 333 611 435 300 200 160
250  720 600 403 641 435 350 250 200
315  1020 900 453 744 500 415 315 250
355  1020 900 525 829 585 455 355 250
400  1020 900 570 1021 715 500 400 315
500  1020 900 713 1296 950 600 500 355



HFD/B, mm

NS  L  L1  L2  W  W1  H  ØD  ØD1 
125  760 640 325 486 410 305 125 100
160  760 640 325 486 410 340 160 125
200  760 640 373 611 515 380 200 160
250  760 640 443 641 515 430 250 200
315  1060 940 453 784 580 495 315 250
355  1060 940 525 869 665 535 355 250
400  1060 940 570 1051 795 580 400 315
500  1060 940 713 1326 1030 680 500 355

Version
S = Standard insulation, B = Extra insulation


Material


MATERIAL AND FINISHING


PART  MATERIAL  NOTE 
Casing Galvanised steel  
Sound attenuation
material
Mineral wool Surface protection layer
Damper blade Galvanised steel  
Blade gasket Neoprene Sizes 100...315
Blade gasket EPDM rubber Sizes 400 and 355
Seals between
accessories
PVC rubber  
Duct gasket EPDM rubber  
Measurement
probe
Aluminium  

Function


FUNCTION


Variable airflow setting

The cold and warm air ducts are connected to the mixing box. The cold duct connection size is equal to the nominal size of the device, and the warm duct connection is one duct size smaller. The mixing box is equipped with two electric airflow controllers.

In variable airflow application, the warm duct inlet is equipped with the airflow rate measurement probe, and the measurement probe of the outlet of the mixing box measures the total airflow rate. Based on the outlet airflow measurement, the mixed airflow rate is controlled so as to correspond to the total airflow setpoint regardless of the mixing ratio and duct pressure changes. The warm duct airflow rate, and consequently the mixing ratio, is controlled by the room temperature control signal according to the control sequence presented in the figure below. The control signals (heating and total flow) can be received from a stand-alone room controller or from a building management system.



Constant total airflow setting

The cold and warm air ducts are connected to the mixing box, and both duct connections are of equal size to the nominal size of the unit. The mixing box is equipped with two electric airflow controllers.

In constant airflow application, both duct inlet connections are equipped with airflow measurement probes. The mixing ratio and total airflow rate are controlled by building management system control signals (heating and cooling) so that the desired supply air temperature and airflow rate are obtained as described for the control sequence in the figure below.



Product Models


PRODUCT MODELS

The HFD airflow management unit is available in several versions. An integral blade gasket enables tight shut-off operation, and external insulation is used to attenuate radiated sound into the space.

MODEL  FEATURE  COMMENT 
HFD/S Supply air Standard insulation: 25 mm
HFD/B Supply air with
extra insulation
Insulation: 65 mm


Control units (CU)

EE = Halton NMV-D2-MP
ED = Belimo VRD2+NM24A-V
EG = Siemens GLB181.1E/3

Controllers EE and ED include a dynamic differential pressure sensor with a low airflow rate through the sensor element. Therefore, these controllers shall not be used in highly contaminated environments. The pressure sensor of the EG unit is based on a membrane with no flow through the sensor element.

Controller ED includes two potentiometers for minimum and maximum airflow setpoint adjustment (ranges: minimum = 0…80% and maximum = 30…100%).

Sound Attenuators


SOUND ATTENUATORS

Sound attenuators are available 600 or 900 mm in length, with insulation material of mineral wool.
External insulation thickness corresponds to the HFD model, 25 mm or 65 mm.

Attenuator length:
-  600 mm is used for duct size range 100...250 mm.
-  900 mm is used for duct size range 315...500 mm.

SA = Attenuator with baffle
SX = Attenuator without baffle



SA/SX-HFD/S, attenuation material thickness of 25 mm

NS  L  H  W  B  kg 
100  600 225 330 160 10.0
125  600 225 330 160 10.0
160  600 260 330 120 10.0
200  600 300 435 160 11.5
250  600 350 435 120 11.0
315  900 415 500 120 18.0
355  900 455 585 2x120 27.0
400  900 500 715 2x120 33.0
500  900 600 950 3x120 53.5

SA/SX-HFD/B, attenuation material thickness of 65 mm

NS  L  H  W  B  kg 
100  600 305 410 160 14.0
125  600 305 410 160 14.0
160  600 340 410 120 15.0
200  600 380 515 160 16.5
250  600 430 515 120 16.0
315  900 495 580 120 21.0
355  900 535 665 2x120 32.0
400  900 580 795 2x120 42.0
500  900 680 1030 3x120 63.5

Connections

Connections
 



There are eight (8) different outlet connection options available for the HFD dual duct airflow management damper.

For constant airflow applications seven (7) connection models can be used:

  • F1: This connection model is developed to connect circular duct directly to the HFD unit, without sound attenuator. If sound attenuator is used, please select the FC connection model in order to allow proper air mixing after sound attenuator.
  • FB, FC, FG, FJ and FN: To connect one or more ducts to HFD unit. All these can also be used with sound attenuator.
  • FI: This model is used to connect the HFD directly to a diffuser.

For variable airflow applications outlet duct connection model FT is used.
The connection module FT is equipped with a total airflow rate measurement probe.

e = attenuation material thickness [mm]
 

HFD e = 25   e = 65   F1   FB   FC   FG
NS H W H W 1 x D L1 2 x D L1 1 x D L1 1 x D L1
100 225 330 305 410 125 65 125 225 125 200 160 260
125 225 330 305 410 160 65 125 225 160 200 160 260
160 260 330 340 410 200 65 160 260 200 200 200 300
200 300 435 380 515 250 65 200 300 250 200 250 350
250 350 435 430 515 315 65 250 350 315 200 315 415
315 415 500 495 580 355 65 315 415 355 200 355 455
355 455 585 535 665 400 80 355 455 400 200 400 500
400 500 715 580 795 450 80 400 500 450 200 450 660
500 600 950 680 1030 500 80 500 660 500 300 500 660

 

 

HFD

e = 25   e = 65   FI   FJ   FN   FT

 

NS H W H W 1 x D L1 3 x D L1 4 x D L1 D L
100 225 330 305 410 <=160 260 100 350 100 350 - -
125 225 330 305 410 <=200 260 100 350 100 350 125 395
160 260 330 340 410 <=250 300 125 400 125 400 160 425
200 300 435 380 515 <=315 350 160 470 160 470 200 425
250 350 435 430 515 <=355 415 200 550 200 550 250 425
315 415 500 495 580 <=400 455 250 650 250 650 315 425
355 455 585 535 665 <=400 500 315 780 315 780 355 465
400 500 715 580 795 <=500 660 355 860 355 860 400 465
500 600 950 680 1030 <=500 660 400 950 400 950 500 465

Installation


INSTALLATION


Safety distances

The airflow control damper is installed with attention to required safety distances (see figure).


 

Wiring

The wiring shall be carried out in accordance with local regulations and by professional technicians.

For the power supply of all control options a safety-isolating transformer shall be used.

HFD; CU=EE (NMV-D2-MP) - variable or constant airflow control



CODE  DESCRIPTION
Halton  Delivered by Halton
3 rd party  Delivered by a third party
1 ( ^ )  24 VAC system neutral
2 (~)  24 VAC live
3 (w)  0…10-VDC airflow setpoint signal input
5 (U5)  0…10-VDC airflow feedback signal output
RC  Room controller
PLC  Building management system
C(AO)  Airflow setpoint, unit total airflow
H(AO)  Airflow setpoint, heating
F(AI)  Actual airflow feedback input

HFD; CU=EE (NMV-D2-MP) - variable or constant airflow control



CODE  DESCRIPTION
Halton  Delivered by Halton
3 rd party  Delivered by a third party
1 ( ^ )  24 VAC system neutral
2 (~)  24 VAC live
3 (w)  0…10-VDC airflow setpoint signal input
5 (U5)  0…10-VDC airflow feedback signal output
RC  Room controller
PLC  Building management system
C (AO)  Airflow setpoint control signal
F (AI)  Actual airflow feedback input
 

Commissioning


COMMISSIONING

Airflow control

Nominal airflow rates of the HFD are presented in the table below.
 

NS qv_nominal NS qv_nominal
100 73 l/s
263 m 3 /h
315 874 l/s
3145 m 3 /h
125 121 l/s
436 m 3 /h
355 1120 l/s
4031 m 3 /h
160 208 l/s
749 m 3 /h
400 1433 l/s
5159 m 3 /h
200 336 l/s
1210 m 3 /h
500 2267 l/s
8161 m 3 /h
250 539 l/s
1940 m 3 /h
   


The actual measured airflow rate (qv) can be defined by the controller feedback signal (U or U5) and airflow controller nominal airflow (qv_nom).
 

SIGNAL FORMULA CONTROLLER TYPE
AND MODE
TERMINALS
SYSTEM
NEUTRAL
TERMINALS
SIGNAL
0...10
VDC
qv = qv_nom * U/10 HFD;CU=EE
(NMV-D2-MP),
mode 0...10 V
HFD;CU=EG
(GLB181.1E/3)
1 (GND)


2(G0)
5 (U5)


9 (U)
2...10
VDC
qv = qv_nom * (U-2)/8 HFD;CU=EE
(NMV-D2-MP),
mode 2...10 V
HFD;CU=ED
(VRD2+NM24-V)
1 (GND)


1 (GND)
5 (U5)


5 (U5)

The actual airflow rate can also be determined from the pictures below.



The actual airflow rate can be calculated as a function of differential pressure at the measurement probe and the measurement probe k factor. The proper k factor can be found in an attachment for the product.



qv  actual airflow rate [l/s]
k  k value of the product
dP_m  differential pressure of measurement probe [Pa]

The EE and ED airflow controllers are equipped with a dynamic pressure differential sensor, and there is a low airflow rate through the pressure sensor. Therefore, a manual manometer cannot be connected in parallel with the airflow controller for differential pressure measurement. If a manometer will be used, the airflow controller power supply shall be switched off in order to stop damper movement during measurement of airflow probe differential pressure. Note that the duct pressure might vary during the measurement.

The EG airflow controller is equipped with a static membrane pressure sensor including automatic zero point calibration, and there is no airflow through the differential pressure sensor of the controller. Therefore, a manual differential measurement manometer can be connected in parallel to the airflow controller (for example with tube T-branches) and both measurements can operate in parallel with continuous control.
 

Specification


SUGGESTED SPECIFICATIONS

The dual duct mixing unit shall be made of galvanised steel with airflow measurement probes of aluminium.
Duct connections D = 100…500 mm shall include airtight neoprene or EPDM rubber gaskets. Damper blades shall include rubber gaskets.

The dual duct unit shall comprise airflow measurements, flow controllers and damper actuators. Design airflow range limits shall be calibrated at the factory.

The casing shall be acoustically insulated with 25-mm-thick mineral wool to avoid airborne noise emission into the duct and radiation of noise through the damper casing. When specified, unit design shall have additional external insulation containing 40 mm of acoustic material and a galvanised steel cover applied over the standard casing.

The dual duct unit shall be equipped with a sound attenuator in order to meet the sound level requirement for the room. As an option, the sound attenuator shall contain a central baffle.

Product Code


PRODUCT CODE


HFD/S-D

   S = Model
    S  Standard insulation
    B  Extra insulation

   D = Connection size
    125, 160, 200, 250, 315, 355, 400, 500


Specifics and accessories

   CU = Control unit
    EE  NMV-D2-MP (Belimo)
    ED  VRD2+NM24A-V (Belimo)
    EG  GLB181.1E/3 (Siemens)

   SA = Sound attenuator
    NA  Not assigned
    H1  HFD | Standard insulation | With baffle
    H2  HFD | Standard insulation | Without baffle
    H3  HFD | Extra insulation | With baffle
    H4  HFD | Extra insulation | Without baffle

   HT = Outlet connection type
    F1  CAV: Outlet plenum | 1 pc., direct duct connection
    FB  CAV: Outlet plenum | 2 pcs., side duct connections
    FC  CAV: Outlet plenum | 1 pc., back duct connection
    FG  CAV: Outlet plenum | 1 pc., side duct connection
    FI  CAV: Outlet plenum | 1 pc., side diffuser connection
    FJ  CAV: Outlet plenum | 3 pcs., side duct connections
    FN  CAV: Outlet plenum | 4 pcs., side duct connections
    FT  VAV: Outlet plenum with measurement probe | 1 pc, direct duct connection

Code example

   HFD/S-125, CU=EE, SA=NA, HT=F1, ZT=N

Downloads & Media

Halton HFD - nl
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Language
neerlandés (Países Bajos)
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1.0 MB
Halton HFD - it
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italiano (Italia)
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Halton HFD - uk
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inglés (Reino Unido)
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Halton HFD - fi
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finés (Finlandia)
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Halton HFD - ru
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ruso (Rusia)
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Halton HFD - se
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sueco (Suecia)
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