Finally printed the BentoBox recirculating airfilter and made some changes to it and some nice cable management inside the P1S for 12V. I use the filter mainly when printing ABS/ASA to avoid VOCs and that nasty white deposit that accumulates over time on the interior. Another benefit is that I’ve found out from others - the temperature is more homogeneous and this avoids warping with ABS/ASA.

I didn't like the way the cables hung under the fans. That's why I made a remix and integrated a cable duct into the fancase. The cable goes through one of the free fan holes into the cable routing connecting both fans together. The fanduct I also made compatible with the more available M3 inserts from ruthex M3 x 5.7mm.

I drilled a hole in the interior of the P1S and inserted a rubber grommet for a nice looking cable management. On the backplate I used a DC socket for 12V and soldered a cable with a JST connector to it. The 2x server fans from Arctic S4028-15K have each 15K RPM/20cfm and they're like turbines. I tried a cheap LED dimmer to control their speed and it works but the square PWM signal from the dimmer is pretty loud and the motors begin to sing. But I found a small universal dc power supply with adjustable voltage 3V, 4.5V, 5V, 6V, 7.5, 9V, 12V - and I use it at 7.5V - 9V that works really well.