EXHAUSTO DTV, DTH and VVR fans are measured with a straight pipe (length 3 x diameter) immediately before the fan.

A system pressure drop can occur if the minimum distance is not maintained during installation and this should be taken into consideration during project engineering. The size of this system pressure drop is calculated using the research literature.

DTV, DTH and VVR are measured with a pipe that has the same dimensions as the fan’s spigot, apart from the DTV450-4-1FC fan, which is measured with a pipe with diameter of 500.

The stated operating curves show the characteristics of the fan with downwards regulation.

The SFP curves show the specific electricity used in J/m3 ventilated air volume through the fan.


Thik line Capacity data
Doddet line SFP curve (J/m3)
Thin line Operating curves

Measurement set-up

 DTV måleopstilling, kapacitet

pt = total pressure
Temperature = 20 °C
Density = 1.2 kg/m3
SFP = specific power consumption for air transport (J/m3)
qv = volume flow (l/s)
P1 = absorbed power (Watt)

P1 = SFP x qv x 10-3 = SFP (J/m3) x qv (l/s):1000
( 1000 l/s = 1 m3/s) 

Calculation programs

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Vex overview

VEX Summary

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