Speed Control
All KAT./KAF. type fans are speed-controllable by frequency converter. All models marked „Stb.“ are also suitable for speed control by transformer.
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 show the total pressure increase Δ pt 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 ascertaining of the sound level follows the enveloping surface method according to DIN 45 635 section 38. The figures in the air performance curves represent the A-weighted sound power level radiated to the surrounding (LWA2) in decibels. The A-weighted sound power level at the outlet side LWA6 according to DIN 45 635, part 38, is obtained approximately as follows: LWA5 = LWA2 + 20 dB(A)
The A-weighted sound power level at the inlet side LWA5 according to DIN 45 635, part 38, is obtained approximately as follows: LWA5 = LWA6 - 3 dB(A)
The octave sound power level is important for the choice of suitable sound attenuators. It is obtained as follows. LWAOkt = LWA + LWArel
The relative octave sound power level LWArel at octave medium frequency can be taken from the tables. These levels has been established at 0.5 x Vmax.
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.