Oh screw it. I ended up at 35C immediately. Im returning the fan tomorrow, and getting this instead:

*TD 350/125.
*125 mm.
*50W.
*Decibel 48/39 dB(A).
*Max. air 370 m³/hour.
*Diam. 155 mm.
*Length 290 mm.
*230 V.

Thats more than twice the power.
Might as well do this properly.
.