With this air duct you have the option of replacing the loud radial fan in your Creality SpacePi with a quiet 60 mm axial fan. I used the Noctua NF-A6x25 FLX. This fan is particularly quiet, runs on 12 volts and can handle temperatures of up to 65 degrees Celsius.
The volumetric flow is slightly lower than that of the original fan, but absolutely sufficient for drying filament.
To disassemble the SpacePI you have to loosen 4 screws under the rubber feet and then the cover on the display. Below the cover there are 4 screws around the display. You have to loosen this and then you can carefully remove the plexiglass on the front. Then remove four more srews and the display and access the two Phillips screws underneath. Once you have solved this, you should be able to remove the base plate.

Now remove the original fan by removing the connector and loosening the two fan mounting screws. The axial fan gets pressed and glued in the air duct. I used aluminum tape for this, to isolate the fan a bit from the heat.

Don't be surprised, the fit is very tight, but it should work. Pay attention to the main power cables during assembly. You may have to remove the cable lugs so that they don't interfere with the fan. Than everything in reverse.

There is now a V2, that has a smaller Opening on the Heaterside.
Make sure what Version of the SpacePi you have, because there seem to be multiple Versions.

Have fun and enjoy a silent drybox.