Application
Special features
Nominal sizes
Parts and characteristics
Attachments
Useful additions
Construction features
Easy controller
Compact controller
Materials and surfaces
Standards and guidelines
Maintenance
Functional description
A new measurement principle makes it possible to measure low volume flow rates. The pressure is measured by means of a nozzle with tappings before (upstream) and after (downstream) the damper blade. The Easy controller or the Compact controller of the LVC determines the resulting differential pressure (effective pressure) and compares it to the stored characteristic.
This measurement principle is characterised by small measuring tolerances, and the upstream conditions do not have to meet any special requirements.
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.
l/s | m³/h | ① Pa | ② Pa | ③ Pa | ④ Pa | ± % | |
Nominal sizes | 125 – 250 mm |
Volume flow rate range | 8 – 300 l/s or 30 – 1080 m³/h |
Volume flow rate control range | Approx. 10 to 100% of the nominal volume flow rate |
Minimum differential pressure | 5 – 30 Pa |
Maximum differential pressure | 600 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.
LVC, Sound pressure level at differential pressure 50 Pa
125 | 8 | 29 | 27 | <15 | <15 | <15 | <15 |
125 | 30 | 108 | 35 | 24 | 17 | <15 | 17 |
125 | 55 | 198 | 39 | 30 | 24 | 21 | 21 |
125 | 75 | 270 | 42 | 34 | 28 | 25 | 23 |
160 | 12 | 43 | 29 | 19 | <15 | <15 | <15 |
160 | 50 | 180 | 34 | 26 | 23 | 19 | 19 |
160 | 85 | 306 | 36 | 28 | 23 | 20 | 22 |
160 | 120 | 432 | 38 | 31 | 26 | 23 | 24 |
200 | 20 | 72 | 31 | 21 | <15 | <15 | <15 |
200 | 75 | 270 | 35 | 26 | 19 | 17 | 19 |
200 | 135 | 486 | 36 | 28 | 22 | 20 | 22 |
200 | 190 | 684 | 36 | 28 | 23 | 21 | 24 |
250 | 30 | 108 | 31 | 24 | 18 | 16 | 17 |
250 | 120 | 432 | 36 | 28 | 22 | 19 | 25 |
250 | 210 | 756 | 36 | 28 | 22 | 20 | 28 |
250 | 300 | 1080 | 36 | 29 | 23 | 21 | 31 |
① LVC
② LVC with secondary silencer CS/CF, insulation thickness 50 mm, length 500 mm
③ LVC with secondary silencer CS/CF, insulation thickness 50 mm, length 1000 mm
④ LVC with secondary silencer CS/CF, insulation thickness 50 mm, length 1500 mm
Circular VAV terminal units for variable air volume systems with low airflow velocities, suitable for supply or extract air, available in four nominal sizes.
Measurement and control of low volume flow rates based on a new measurement principle. Plastic nozzle with damper blade for measuring the differential pressure upstream and downstream of the damper blade (effective pressure). The relation between damper blade position and differential pressure is stored as a characteristic relationship in the Easy or Compact controller. This results in high control accuracy even in case of unfavourable upstream conditions.
Selection based on nominal size determination.
Ready-to-commission unit which consists of the mechanical parts and the electronic control components. Units are equipped with a plastic nozzle with integral damper blade.
The averaging differential pressure sensor is resistant to dust and pollution.
Spigot with lip seal, for circular connecting ducts to EN 1506 or EN 13180.
Position of the damper blade indicated externally at shaft extension. Damper blade is factory set to open position which allows ventilation airflow even without control.
Closed blade air leakage to EN 1751, at least class 1.
Casing air leakage to EN 1751, class C.
Special features
Materials and surfaces
Technical data
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.
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
Air-regenerated noise
Case-radiated noise
This specification text describes the general properties of the product. Texts for variants can be generated with our Easy Product Finder design programme.
Order example: LVC/160/Easy
Nominal size | 160 mm |
Attachment | Easy controller |
LVC, VARYCONTROL control components
Easy controller | ||||
Easy | Volume flow rate | Easy controller TROX | Dynamic, integral | Integral |
Compact controller | ||||
BC0 | Volume flow rate | Compact controller with MP bus interface TROX/Belimo | Dynamic, integral | Integral |
mm | kg | |
1.5 | ||
1.9 | ||
2.1 | ||
2.7 |
Installation and commissioning
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.
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
VARYCONTROL | |||
Easy controller | 370 | 200 | 300 |
Compact controller | 370 | 200 | 200 |
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 %)
Vmin unit [m³/h] and [l/s]
Technically possible minimum volume flow rate
Vmax [m³/h] and [l/s]
Upper limit of the operating range for the VAV terminal unit that can be set by customers
Vmin [m³/h] and [l/s]
Lower limit of the operating range for the VAV terminal unit that can be set by customers
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
Construction
Galvanised sheet steel
Powder-coated surface (P1)
Stainless steel (A2)
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Ditt meddelande har skickats och kommer att behandlas inom kort tid. Vår serviceavdelning återkommer til dig så snart vi har möjlighet.