Fan Performance Curves
The performance curves for these fans have been established using the inlet test method in the test chamber according to DIN 24 1 63, mounting position D (connected at both sides). The curves indicate the static pressure increase ∆ pst, for direct driven fans, the total pressure increase ∆ pt, for belt driven fans, as a function of the volume flow. The dynamic pressure ∆ pd2 shown in the performance curves refers to the cross-section of the fan outlet flange.
Noise Levels
The figures quoted in the performance curves are the “A” decibel figures which are the sound power levels LWA6 at the outlet side in duct systems. The “A” sound power level at the inlet side LWA5, according to DIN 45 635, part 38, can be calculated via the relative sound power levels (see below) or is obtained approximately as follows:
LWA5 ≈ LWA6 - 6 dB
The “A” casing sound power level LWA2, according to DIN 45 635, part 38, can be calculated via the relative sound power levels (see below) or is obtained approximately as follows: LWA2 ≈ LWA6 - 25 dB
The “A” sound pressure level LPA at a distance of 1 meter is obtained approximately by deducting 7 dB(A) from the “A” sound power level.: LPA(1m) ≈ LWA2 - 7 dB
It is important to note that the reflection and room characteristic as well as natural frequencies differently influence the sound pressure levels. In order to avoid bone conduction transfer to a connected duct system we recommend the use of flexible duct connection.
The A-weighted octave sound power level is important for the choice of suitable sound attenuators. It is obtained as follows: LWAokt = LWA6 + LWArel