TVR

Volume flow rate ranges

The minimum differential pressure of VAV terminal units 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.

The volume flow rates given for VAV terminal units depend on the nominal size and on the control component (attachment) that is installed. The table gives the minimum and maximum values for a VAV terminal unit. Some control components may only have a limited volume flow rate range. This applies in particular to control components with a static differential pressure transducer. For volume flow rate ranges for all control components refer to our Easy Product Finder design programme.

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.

TVR, Sound pressure level at differential pressure 150 Pa

① TVR

② TVR with secondary silencer CS/CF, insulation thickness 50 mm, length 500 mm

③ TVR with secondary silencer CS/CF, insulation thickness 50 mm, length 1000 mm

④ TVR with secondary silencer CS/CF, insulation thickness 50 mm, length 1500 mm

⑤ TVR-D

Circular VAV terminal units for variable and constant air volume systems, suitable for supply or extract air, available in seven nominal sizes.

High control accuracy (even with upstream bend R = 1D).

Ready-to-commission unit which consists of the mechanical parts and the electronic control components. Each unit contains an averaging differential pressure sensor for volume flow rate measurement and a damper blade. Factory assembled control components complete with wiring and tubing.

Differential pressure sensor with 3 mm measuring holes (resistant to dust and pollution)

Spigot with groove for lip seal, suitable for connecting ducts according to EN 1506 or EN 13180.

Position of the damper blade indicated externally at shaft extension.

Closed blade air leakage to EN 1751, class 4 (nominal size 100, class 2; nominal sizes 125 and 160, class 3).

Casing air leakage to EN 1751, class C.

Special characteristics

• Integral differential pressure sensor with 3 mm measuring holes (resistant to dust and pollution)
• Factory set-up or programming and aerodynamic function testing
• Volume flow rate can be measured and subsequently adjusted on site; additional adjustment tool may be necessary

Materials and surfaces

Galvanised sheet steel construction

• Casing and damper blade made of galvanised sheet steel
• Damper blade seal made of TPE plastic
• Aluminium sensor tubes
• Plastic bearings

Powder-coated construction (P1)

• Casing made of galvanised sheet steel, powder-coated
• Damper blade and shaft made of stainless steel 1.4301
• Sensor tubes made of aluminium, powder-coated

Stainless steel construction (A2)

• Casing, damper blade and shaft made of stainless steel 1.4301
• Sensor tubes made of aluminium, 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/EG

Construction

• Galvanised sheet steel
• P1: Powder-coated, silver grey (RAL 7001)
• A2: Stainless steel

Technical data

• Nominal sizes: 100 to 400 mm
• Volume flow rate range: 10 to 1680 l/s or 36 to 6048 m³/h
• Volume flow rate control range (unit with dynamic differential pressure measurement): approx. 10 to 100 % of the nominal volume flow rate
• Minimum differential pressure: 5 – 90 Pa
• Maximum differential pressure: 1000 Pa

Attachments

Variable volume flow control with electronic Easy controller to connect an external control signal; actual value signal can be integrated into the central BMS.

• Supply voltage 24 V AC/DC
• Signal voltages 0 – 10 V DC
• Possible override controls with external switches using volt-free contacts: CLOSED, OPEN, Vmin and Vmax
• Potentiometers with percentage scales to set the volume flow rates Vmin and Vmax
• The actual value signal relates to the nominal volume flow rate such that commissioning and subsequent adjustment are simplified
• Volume flow rate control range: approx. 10 – 100 % of the nominal volume flow rate
• Clearly visible external indicator light for signalling the functions: Set, not set, and power failure

Electrical connections with screw terminals. Double terminals for looping the supply voltage, i.e. for the simple connection of voltage transmission to the next controller.

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.

TVR, VARYCONTROL control components

TVR, LABCONTROL control components

Principal dimensions

ØD [mm]

VAV terminal units made of stainless steel: Outside diameter of the spigot

VAV terminal units made of plastic: Inside diameter of the connecting 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 (e.g. Compact controller)

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.
• Reference value for calculating percentages (e.g. Vmax)
• Upper limit of the setting range and maximum volume flow rate setpoint value for the VAV terminal unit

Vmin unit [m³/h] and [l/s]

Technically possible minimum volume flow rate

• The value depends on product type, nominal size and control component (attachment)
• Values are stored in the Easy Product Finder design software
• Lower limit of the setting range and minimum volume flow rate setpoint value for the VAV terminal unit
• Depending on the controller, setpoint values below Vmin unit (if Vmin equals zero) may result in unstable control or shut-off

Vmax [m³/h] and [l/s]

Upper limit of the operating range for the VAV terminal unit that can be set by customers

• Vmax can only be smaller than or equal to Vnom
• In case of analogue signalling to volume flow controllers (which are typically used), the set maximum value (Vmax) is allocated to the setpoint signal maximum (10 V) (see characteristic)

Vmin [m³/h] and [l/s]

Lower limit of the operating range for the VAV terminal unit that can be set by customers

• Vmin should be smaller than or equal to Vmax
• Do not set Vmin smaller than Vmin unit, otherwise the control may become unstable or the damper blade may close
• Vmin may equal zero
• In case of analogue signalling to volume flow controllers (which are typically used), the set minimum value (Vmin) is allocated to the setpoint signal minimum (0 or 2 V) (see characteristic)

V [m³/h] and [l/s]

Volume flow rate

ΔV [± %]

Volume flow rate tolerance from setpoint value

ΔVwarm [± %]

Volume flow rate tolerance for the warm air flow of dual duct terminal units

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 VAV terminal unit when the damper blade is open, caused by flow resistance (sensor tubes, damper mechanism)
• If the pressure on the VAV terminal unit 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 terminal units, 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