Fan Performance Curves
The performance curves for these fan types have been established in mounting position B (installed on the pressure side and open on the suction side) and represent the static pressure increase Dpst as a function of the volume flow. The dynamic pressure pd2 refers to the flange cross-sectional area of the fan outlet.
Sound Levels
The sound figures given in the fan performance curves are the A-weighted sound power levels LWA6 at the outlet side, unducted, in decibels. The Aweighted sound power level at the inlet side LWA5 according to DIN 45 635, part 38, is obtained as follows:
LWA5 = LWA6 - 3 dB(A)
The A-weighted sound pressure level LPA at a distance of 1 metre is obtained approximately by deducting 7 dB(A) from the A-weighted sound power level LWA.
It is important to note that reflexion and environmental characteristics as well as resonant frequencies influence the sound pressure levels in different ways.The octave sound power level is important for the choice of suitable sound attenuators. It is obtained as follows. LWAOkt = LWA6 + LWArel