Type EN

For the precise control of normal and high constant volume flows

Rectangular self-powered volume flow controllers for the control of supply air or extract air in constant air volume systems

  • Suitable for volume flow rates up to 12,096 m³/h or 3,360 l/s
  • Volume flow rate can be set using an external scale, no tools required
  • High control accuracy
  • No on-site test measurements required for commissioning
  • Suitable for airflow velocities of up to 8 m/s
  • Casing air leakage to EN 1751, up to class C


Optional equipment and accessories

  • Acoustic cladding for the reduction of case-radiated noise
  • Secondary silencer Type TX for the reduction of air-regenerated noise
  • Hot water heat exchanger of Type WT for reheating the airflow
  • Actuator for switching between setpoint values

Volume flow controller Type EN 00136149_0


  • Application
  • Description

Application

  • Rectangular CONSTANTFLOW CAV controllers of Type EN for the precise supply air or extract air flow control in constant air volume systems
  • Mechanical self-powered volume flow control without external power supply
  • Simplified project handling with orders based on nominal size

Special characteristics

  • Volume flow rate can be set using an external scale; no tools required
  • High volume flow rate control accuracy
  • Any installation orientation
  • Correct operation even under unfavourable upstream conditions (1.5 B straight section required upstream)

Nominal sizes

  • 19 nominal sizes from 200 × 100 to 600 × 600

Variants

  • EN: Volume flow controller
  • EN-D: Volume flow controller with acoustic cladding
  • Units with acoustic cladding and/or secondary silencer Type TX for demanding acoustic requirements
  • Acoustic cladding cannot be retrofitted

Construction

  • Galvanised sheet steel
  • P1: Powder-coated, silver grey (RAL 7001)

Parts and characteristics

  • Ready-to-commission controller
  • Damper blade with low-friction bearings
  • Bellows that acts as an oscillation damper
  • Cam plate with leaf spring
  • Scale with pointer to set the volume flow rate setpoint
  • Aerodynamic function testing of each unit on a special test rig prior to shipping

Attachments

  • Min/Max actuators: Actuators for switching between minimum and maximum volume flow rate setpoint values
  • Modulating actuators: Actuators for the stepless adjustment of volume flow rates or to switch between minimum and maximum volume flow rate setpoint values
  • Retrofit kits: Actuators and installation accessories
  • EN with actuator only up to H = 300 mm

Useful additions

  • Secondary silencer Type TX
  • Heat exchanger Type WT

Construction features

  • Rectangular casing
  • Flanges on both sides, suitable for duct connection
  • Volume flow controllers from H = 400 mm are fitted with two damper blades and two volume flow rate scales

Materials and surfaces

Galvanised sheet steel construction

  • Casing and damper blade made of galvanised sheet steel
  • Leaf spring made of stainless steel
  • Polyurethane bellows
  • Plain bearings with PTFE coating


Powder-coated construction (P1)

  • Casing and damper blade made of galvanised sheet steel, powder-coated


Variant with acoustic cladding (-D)

  • Acoustic cladding made of galvanised sheet steel
  • Rubber profile for the insulation of structure-borne noise
  • Lining is mineral wool


Mineral wool

  • To EN 13501, fire rating class A1, non-combustible
  • RAL quality mark RAL-GZ 388
  • Biosoluble and hence hygienically safe according to the German TRGS 905 (Technical Rules for Hazardous Substances) and EU directive 97/69/EC

Standards and guidelines

  • Casing air leakage to EN 1751, class C (B + H ≤400, class B)

Maintenance

  • Maintenance-free as construction and materials are not subject to wear

Technical information

Function, Technical data, Quick sizing, Specification text, Order code, Produktbeziehungen

  • Function
  • Technical data
  • Quick sizing
  • Specification text
  • Order code
Schematic illustration of the EN 00131435_0
① Volume flow rate scale
② Volume flow rate scale lock
③ Crossbar
④ Cam plate
⑤ Leaf spring
⑥ Bellows inlet
⑦ Bellows
⑧ Damper blade


Functional description

The volume flow controller is a mechanical self-powered unit and works without external power supply. A damper blade with low-friction bearings is adjusted by aerodynamic forces such that the set volume flow rate is maintained within the differential pressure range.

The aerodynamic forces of the airflow create a closing torque on the damper blade. The bellows extends and increases this force while at the same time acting as an oscillation damper. The closing force is countered by a leaf spring that unrolls over a cam plate. The shape of the cam plate is such that a change in the differential pressure leads to an adjustment of the damper blade in a way that the volume flow rate is maintained almost exactly.

Efficient commissioning

The volume flow rate setpoint value can be set quickly and easily using the pointer on the external scale; no measurements are required.

The advantage over flow adjustment dampers is that there is no need for repeat measurements or adjustments by an air conditioning engineer. Should the system pressure change, e.g. by opening or closing of duct sections, the flow rates in the entire system will also change if flow adjustment dampers are used; however, this is not the case with mechanical self-powered volume flow controllers A mechanical self-powered controller reacts immediately and adjusts the damper blade such that the set constant volume flow rate is maintained.

Volume flow rate ranges

The minimum differential pressure of CAV controllers is an important factor in designing the ductwork and in rating the fan including speed control.

Sufficient duct pressure must be ensured for all operating conditions and for all control units. The measurement points for fan speed control must be selected accordingly.

Nominal size
V
l/s
V
m³/h

∆pst min
Pa

∆pst min
Pa
∆V
± %
200 × 100 40 144 50 60 13
200 × 100 80 288 50 80 9
200 × 100 120 432 50 115 6
200 × 100 160 576 50 160 5
300 × 100 65 234 50 60 13
300 × 100 130 468 50 80 9
300 × 100 195 702 50 120 6
300 × 100 260 936 50 170 5
300 × 150 105 378 50 60 13
300 × 150 210 756 50 80 9
300 × 150 315 1134 50 115 6
300 × 150 420 1512 50 160 5
300 × 200 130 468 50 60 13
300 × 200 260 936 50 80 9
300 × 200 390 1404 50 110 6
300 × 200 520 1872 50 160 5
400 × 200 210 756 50 60 13
400 × 200 420 1512 50 80 9
400 × 200 630 2268 50 115 6
400 × 200 840 3024 50 160 5
500 × 200 230 828 50 60 13
500 × 200 460 1656 50 80 9
500 × 200 690 2484 50 115 6
500 × 200 920 3312 50 160 5
600 × 200 255 918 50 60 13
600 × 200 510 1836 50 80 9
600 × 200 765 2754 50 115 6
600 × 200 1020 3672 50 160 5
400 × 250 220 792 50 60 13
400 × 250 440 1584 50 80 9
400 × 250 660 2376 50 115 6
400 × 250 880 3168 50 160 5
500 × 250 300 1080 50 60 13
500 × 250 600 2160 50 80 9
500 × 250 900 3240 50 115 6
500 × 250 1200 4320 50 160 5
600 × 250 320 1152 50 60 13
600 × 250 640 2304 50 80 9
600 × 250 960 3456 50 115 6
600 × 250 1280 4608 50 160 5
400 × 300 315 1134 50 60 13
400 × 300 630 2268 50 80 9
400 × 300 945 3402 50 115 6
400 × 300 1260 4536 50 160 5
500 × 300 375 1350 50 60 13
500 × 300 750 2700 50 80 9
500 × 300 1125 4050 50 115 6
500 × 300 1500 5400 50 160 5
600 × 300 420 1512 50 60 13
600 × 300 840 3024 50 75 9
600 × 300 1260 4536 50 110 6
600 × 300 1680 6048 50 150 5
400 × 400 420 1512 50 60 13
400 × 400 840 3024 50 85 9
400 × 400 1260 4536 50 120 6
400 × 400 1680 6048 50 175 5
500 × 400 460 1656 50 60 13
500 × 400 920 3312 50 80 9
500 × 400 1380 4968 50 115 6
500 × 400 1840 6624 50 160 5
600 × 400 510 1836 50 60 13
600 × 400 1020 3672 50 80 9
600 × 400 1530 5508 50 115 6
600 × 400 2040 7344 50 160 5
500 × 500 600 2160 50 60 13
500 × 500 1200 4320 50 80 9
500 × 500 1800 6480 50 115 6
500 × 500 2400 8640 50 160 5
600 × 500 640 2304 50 55 13
600 × 500 1280 4608 50 70 9
600 × 500 1920 6912 50 95 6
600 × 500 2560 9216 50 130 5
600 × 600 840 3024 50 60 13
600 × 600 1680 6048 50 75 9
600 × 600 2520 9072 50 105 6
600 × 600 3360 12096 50 145 5


Nominal sizes

200 × 100 to 600 × 600 mm

Volume flow rate range

40 – 3360 l/s or 144 – 12096 m³/h

Volume flow rate control range

Approx. 25 to 100 % of the nominal volume flow rate

Scale accuracy

± 4 %

Minimum differential pressure

50 Pa

Maximum differential pressure

1000 Pa

Operating temperature

10 – 50 °C




Quick sizing tables provide a good overview of the room sound pressure levels that can be expected. Approximate intermediate values can be interpolated. Precise intermediate values and spectral data can be calculated with our Easy Product Finder design programme.

The first selection criteria for the nominal size are the actual volume flow rates Vmin and Vmax. The quick sizing tables are based on generally accepted attenuation levels. If the sound pressure level exceeds the required level, a larger air terminal unit and/or a silencer is required.

EN, Sound pressure level at differential pressure 150 Pa

Nominal size V Air-regenerated noise Case-radiated noise
Nominal size V
Nominal size V LPA LPA1 LPA2 LPA3
Nominal size l/s m³/h dB(A)

200 × 100

40

144

35

19

21

<15

200 × 100

80

288

41

28

28

21

200 × 100

120

432

44

34

33

26

200 × 100

160

576

46

38

35

30

300 × 100

65

234

38

22

24

16

300 × 100

130

468

44

30

32

24

300 × 100

195

702

45

35

36

29

300 × 100

260

936

47

38

39

32

300 × 150

105

378

41

24

28

19

300 × 150

210

756

44

31

34

26

300 × 150

315

1134

46

35

39

32

300 × 150

420

1512

47

38

41

35

300 × 200

130

468

45

24

31

21

300 × 200

260

936

46

29

35

26

300 × 200

390

1404

46

33

38

29

300 × 200

520

1872

47

35

40

32

400 × 200

210

756

42

23

30

20

400 × 200

420

1512

43

27

35

26

400 × 200

630

2268

44

31

38

30

400 × 200

840

3024

44

33

40

33

500 × 200

230

828

40

21

28

18

500 × 200

460

1656

40

26

33

24

500 × 200

690

2484

41

29

36

28

500 × 200

920

3312

42

31

38

31

600 × 200

255

918

38

20

27

17

600 × 200

510

1836

39

24

31

23

600 × 200

765

2754

39

28

35

27

600 × 200

1020

3672

40

31

37

31

400 × 250

220

792

44

23

32

22

400 × 250

440

1584

45

28

37

27

400 × 250

660

2376

45

31

39

30

400 × 250

880

3168

45

34

41

33

500 × 250

300

1080

41

21

31

21

500 × 250

600

2160

42

26

36

27

500 × 250

900

3240

43

30

39

30

500 × 250

1200

4320

43

33

41

33

600 × 250

320

1152

40

20

30

20

600 × 250

640

2304

40

25

34

25

600 × 250

960

3456

41

28

37

29

600 × 250

1280

4608

42

31

39

32

400 × 300

315

1134

45

25

53

25

400 × 300

630

2268

46

29

40

30

400 × 300

945

3402

47

34

43

34

400 × 300

1260

4536

47

36

45

36

500 × 300

375

1350

43

22

34

23

500 × 300

750

2700

44

28

38

29

500 × 300

1125

4050

44

31

41

32

500 × 300

1500

5400

45

33

43

35

600 × 300

420

1512

41

21

33

22

600 × 300

840

3024

42

26

37

28

600 × 300

1260

4536

42

30

40

31

600 × 300

1680

6048

43

32

42

34

400 × 400

420

1512

47

27

39

29

400 × 400

840

3024

49

32

44

34

400 × 400

1260

4536

49

36

47

37

400 × 400

1680

6048

50

38

49

40

500 × 400

460

1656

45

24

37

27

500 × 400

920

3312

46

29

42

32

500 × 400

1380

4968

47

33

44

35

500 × 400

1840

6624

47

35

46

37

600 × 400

510

1836

43

22

36

25

600 × 400

1020

3672

44

27

40

30

600 × 400

1530

5508

44

31

43

33

600 × 400

2040

7344

45

33

45

36

500 × 500

600

2160

47

26

40

30

500 × 500

1200

4320

48

31

45

35

500 × 500

1800

6480

49

35

48

39

500 × 500

2400

8640

49

37

50

41

600 × 500

640

2304

45

24

39

28

600 × 500

1280

4608

46

29

43

33

600 × 500

1920

6912

46

32

46

36

600 × 500

2560

9216

46

35

48

39

600 × 600

840

3024

46

26

41

31

600 × 600

1680

6048

47

30

46

36

600 × 600

2520

9072

48

35

49

39

600 × 600

3360

12096

48

37

51

42

① EN

② EN with secondary silencer TX

③ EN-D


Rectangular volume flow controllers for constant air volume systems, mechanical self-powered, without external power supply, suitable for supply or extract air, available in 19 nominal sizes.

Ready-to-commission unit consists of the casing containing a damper blade with low-friction bearings, bellows, external cam plate and leaf spring.

Volume flow controllers without actuators are factory set to a reference volume flow rate (customers can set the required volume flow rate on site).

Both ends suitable for the connection of ducts.

Casing air leakage to EN 1751, class C (B + H ≤400, class B)

Special characteristics

  • Volume flow rate can be set using an external scale; no tools required
  • High volume flow rate control accuracy
  • Any installation orientation
  • Correct operation even under unfavourable upstream conditions (1.5 B straight section required upstream)

Materials and surfaces

Galvanised sheet steel construction

  • Casing and damper blade made of galvanised sheet steel
  • Leaf spring made of stainless steel
  • Polyurethane bellows
  • Plain bearings with PTFE coating


Powder-coated construction (P1)

  • Casing and damper blade made of galvanised sheet steel, powder-coated


Variant with acoustic cladding (-D)

  • Acoustic cladding made of galvanised sheet steel
  • Rubber profile for the insulation of structure-borne noise
  • Lining is mineral wool


Mineral wool

  • To EN 13501, fire rating class A1, non-combustible
  • RAL quality mark RAL-GZ 388
  • Biosoluble and hence hygienically safe according to the German TRGS 905 (Technical Rules for Hazardous Substances) and EU directive 97/69/EC

Construction

  • Galvanised sheet steel
  • P1: Powder-coated, silver grey (RAL 7001)

Technical data

  • Nominal sizes: 200 × 100 to 600 × 600 mm
  • Volume flow rate range: 40 to 3360 l/s or 144 to 12096 m³/h
  • Volume flow rate control range: approx. 25 – 100 % of the nominal volume flow rate
  • Minimum differential pressure: 50 Pa
  • Maximum differential pressure: 1000 Pa

Sizing data

  • V _______________________ [m³/h]
  • Δpst _______________________ [Pa]

Air-regenerated noise

  • LPA _______________________ [dB(A)]

Case-radiated noise

  • LPA _______________________ [dB(A)]

This specification text describes the general properties of the product. Texts for variants can be generated with our Easy Product Finder design programme.

00134835_0

 Type
EN       Volume flow controller

 Acoustic cladding
       No entry: none
D       With acoustic cladding

 Material
       No entry: galvanised sheet steel
P1       Powder-coated (RAL 7001), silver grey

 

 Nominal size [mm]
       B × H

 Actuator
       No entry: without
       For example
B50       24 V AC/DC, 3-point
B52       24 V AC/DC, 3-point, with auxiliary switch
B70       24 V AC/DC, modulating 2 – 10 V DC

 Volume flow rates [m3/h or l/s]
       only actuators
       Vmin – max for factory setting

Order example: EN-D/200×100

Acoustic cladding

With

Material

Galvanised sheet steel

Nominal size

200 × 100 mm


 

Variants, Attachments, Dimensions and weight

  • Variants
  • Attachments
  • Dimensions and weight

EN

  • Volume flow controller for constant air volume flow control

EN-D

  • Volume flow controller with acoustic cladding for constant air volume flow control
  • For rooms where the case-radiated noise of the unit is not sufficiently reduced by a false ceiling
  • The rectangular ducts for the room under consideration must have adequate acoustic insulation (provided by others) on the fan and room ends
  • Acoustic cladding cannot be retrofitted

EN, actuators

Order code detail Actuator Supply voltage Auxiliary switch

Min/Max actuators




B50

Actuator with mechanical stops TROX/Belimo

24 V AC/DC

B52

Actuator with mechanical stops TROX/Belimo

24 V AC/DC

2

B60

Actuator with mechanical stops TROX/Belimo

230 V AC

B62

Actuator with mechanical stops TROX/Belimo

230 V AC

2

Modulating actuators




B70

Actuator with mechanical stops TROX/Belimo

24 V AC/DC

B72

Actuator with mechanical stops TROX/Belimo

24 V AC/DC

2


Nominal size
Nominal width
mm
BN
Nominal height
mm
HN
B1
mm
B2
mm
H1
mm
H2
mm
m
kg
200 × 100 200 100 234 276 134 176 5
300 × 100 300 100 334 376 134 176 6
300 × 150 300 150 334 376 184 226 7
300 × 200 300 200 334 376 234 276 7
400 × 200 400 200 434 476 234 276 9
400 × 250 400 250 434 476 284 326 10
400 × 300 400 300 434 476 334 376 12
400 × 400 400 400 434 476 434 476 18
500 × 200 500 200 534 576 234 276 11
500 × 250 500 250 534 576 284 326 12
500 × 300 500 300 534 576 334 376 13
500 × 400 500 400 534 576 434 476 18
500 × 500 500 500 534 576 534 576 19
600 × 200 600 200 634 676 234 276 13
600 × 250 600 250 634 676 284 326 14
600 × 300 600 300 634 676 334 376 15
600 × 400 600 400 634 676 434 476 18
600 × 500 600 500 634 676 534 576 19
600 × 600 600 600 634 676 634 676 20


Nominal size
Nominal width
mm
BN
Nominal height
mm
HN
B1
mm
B2
mm
H1
mm
H2
mm
m
kg
200 × 100 200 100 234 280 134 180 8
300 × 100 300 100 334 380 134 180 10
300 × 150 300 150 334 380 184 230 11
300 × 200 300 200 334 380 234 280 12
400 × 200 400 200 434 480 234 280 15
400 × 250 400 250 434 480 284 330 17
400 × 300 400 300 434 480 334 380 18
400 × 400 400 400 434 480 434 480 26
500 × 200 500 200 534 580 234 280 17
500 × 250 500 250 534 580 284 330 18
500 × 300 500 300 534 580 334 380 19
500 × 400 500 400 534 580 434 480 26
500 × 500 500 500 534 580 534 580 28
600 × 200 600 200 634 680 234 280 20
600 × 250 600 250 634 680 284 330 22
600 × 300 600 300 634 680 334 380 22
600 × 400 600 400 634 680 434 480 26
600 × 500 600 500 634 680 534 580 29
600 × 600 600 600 634 680 634 680 30




Installation details, Basic information and nomenclature

  • Installation details
  • Basic information and nomenclature

Installation and commissioning

  • Any installation orientation
  • Volume flow rate can be set using an external scale; no tools required
  • No repeat measurements or adjustments by an air conditioning engineer are necessary
  • EN-D: For constructions with acoustic cladding, ducts on the room side should have cladding up to the acoustic cladding of the controller

Upstream conditions

The volume flow rate accuracy ΔV applies to a straight upstream section of the duct. Bends, junctions or a narrowing or widening of the duct cause turbulence that may affect measurement. Duct connections, e.g. branches off the main duct, must comply with EN 1505. Some installation situations require straight duct sections upstream.

Free air intake only with a straight duct section of 1D upstream.

Space required for commissioning and maintenance

Sufficient space must be kept clear near any attachments to allow for commissioning and maintenance. It may be necessary to provide sufficiently sized inspection access openings.

Space required

Attachments
Attachments mm

Without actuator

200

H

200

With actuator

200

H

300

H: Unit height


Prinipal dimensions

ØD [mm]

Outside diameter of the spigot

ØD₁ [mm]

Pitch circle diameter of flanges

ØD₂ [mm]

Outside diameter of flanges

ØD₄ [mm]

Inside diameter of the screw holes of flanges

L [mm]

Length of unit including connecting spigot

L₁ [mm]

Length of casing or acoustic cladding

B [mm]

Duct width

B₁ [mm]

Screw hole pitch of flange (horizontal)

B₂ [mm]

Outside dimension of flange (width)

B₃ [mm]

Width of device

H [mm]

Duct height

H₁ [mm]

Screw hole pitch of flange (vertical)

H₂ [mm]

Outside dimension of flange (height)

H₃ [mm]

Unit height

n [ ]

Number of flange screw holes

T [mm]

Flange thickness

m [kg]

Unit weight including the minimum required attachments for manual adjustment

Acoustic data

fm [Hz]

Octave band centre frequency

LPA [dB(A)]

A-weighted sound pressure level of air-regenerated noise of the VAV terminal unit, system attenuation taken into account

LPA1 [dB(A)]

A-weighted sound pressure level of air-regenerated noise of the VAV terminal unit with secondary silencer, system attenuation taken into account

LPA2 [dB(A)]

A-weighted sound pressure level of case-regenerated noise of the VAV terminal unit, system attenuation taken into account

LPA3 [dB(A)]

A-weighted sound pressure level of case-regenerated noise of the VAV terminal unit with acoustic cladding, system attenuation taken into account


All sound pressure levels are based on 20 μPa.

Volume flow rates

Vnom [m³/h] and [l/s]

Nominal volume flow rate (100 %)

  • The value depends on product type and nominal size
  • Values are published on the internet and in technical leaflets, and stored in the Easy Product Finder design software.
  • Upper limit of the setting range and maximum volume flow rate setpoint value for the CAV controller

V [m³/h] and [l/s]

Volume flow rate

ΔV [± %]

Volume flow rate tolerance from setpoint value

Differential pressure

Δpst [Pa]

Static differential pressure

Δpst min [Pa]

Static differential pressure, minimum

  • The static minimum differential pressure is equal to the pressure loss of the CAV controller when the damper blade is open, caused by flow resistance (bellows, crossbar)
  • If the pressure on the CAV controller is too low, the setpoint volume flow rate may not be achieved, not even when the damper blade is open
  • Important factor in designing the ductwork and in rating the fan including speed control
  • Sufficient duct pressure must be ensured for all operating conditions and for all controllers, and the measurement point or points for speed control must have been selected accordingly to achieve this

Construction

Galvanised sheet steel

  • Casing made of galvanised sheet steel
  • Parts in contact with the airflow as described for the product type
  • External parts, e.g. mounting brackets or covers, are usually made of galvanised sheet steel

Powder-coated surface (P1)

  • Casing made of galvanised sheet steel, powder-coated RAL 7001, silver grey
  • Parts in contact with the airflow are powder-coated or made of plastic
  • Due to production, some parts that come into contact with the airflow may be stainless steel or aluminium, powder-coated
  • External parts, e.g. mounting brackets or covers, are usually made of galvanised sheet steel

Stainless steel (A2)

  • Casing made of stainless steel 1.4201
  • Parts in contact with the airflow are powder-coated or made of stainless steel
  • External parts, e.g. mounting brackets or covers, are usually made of galvanised sheet steel

References

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