How to adjust the number of fan rotations,
continued
Calculation of flow
The flow of the unit can be calculated by measuring the pressure difference between
the suction side of the fan and the inlet cone of the fan.
DanX- modules with plug fans are fitted with a measuring stub which is positioned on
the suction side of the fan and a stub which is positioned in the inlet cone of the fan.
In case of flow a pressure difference will be created between the two measuring points.
The negative pressure in the inlet cone of the fan is getting bigger than on the suction
side of the fan.
Flow and pressure
difference
The relation between flow and pressure difference is as follows:
w
p
K
V
Δ
∗
=
Symbol
Description
Unit
V Messured
flow
[m
3
/h]
w
p
Δ
Pressure difference
[Pa]
K
Constant specifically valid for each single unit size
(see table below)
-
K factor
K for each unit size is shown in the table:
Type
K Factor
DanX 2/4
121
DanX 3/6
154
DanX 5/10
197
DanX 7/14
308
DanX 9/18
381
DanX 12/24
490
DanX 16/32
620
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