Fig. 8: Air direction arrow on the order sticker
Fig. 9: Air direction arrow on the TVLK
Airflow direction control unit TVE
In the case of TVE in combination with a control compo-
nent with a dynamic differential pressure transducer
(Easy, XB0, XM0 (-J6)), the airflow direction is arbitrary.
If Easy, XB0 or XM0(-J6) is listed on the commission
sticker, the airflow direction (Fig. 8/1) specified
there can be ignored.
For the TVE with the Easy control component, this is
indicated by the double arrow (Fig. 10/1) on the scale
label.
Fig. 10: TVE Easy air direction arrow on the scale
sticker
4.5 Upstream conditions
The volume flow rate accuracy of VAV terminal units
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.
Some terminal units require straight upstream duct sec-
tions which are explained below.
4.5.1 Circular ducting
ATTENTION:
Observe air direction arrows on VAV
terminal units during installation
Observe EN 1506 for fittings and bridges, in partic-
ular:
–
No sharp-edged bridges
–
Slants at reductions and expansions per leg
max. 7.5°
Circular silencers CA/CS/CF (same nominal size)
can be installed directly in front of or behind a VAV
terminal unit.
Circular silencer CB (same nominal size)
–
In front of the VAV terminal unit: install at a dis-
tance 1D
–
Behind the VAV terminal unit: install at a dis-
tance 1D (acoustic decoupling)
Connection of fire dampers (same nominal size):
–
In front of the VAV terminal unit: at a distance 1D
–
Behind the VAV terminal unit: without distance,
observe the movement range of the damper
blade.
Installation
Upstream conditions > Circular ducting
VAV terminal units VARYCONTROL
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