I finally got around to actually *do* something with this ground-breaking concept, and tried my hand at using it as a home NAS :-)
First I swapped the Pi3 board I used for the an actual Pi4, and repurposed two 4TB disks in USB enclosures I had lying around.
These heavy boxes were useful for some cable management of sorts, especially the thick USB3 and PSU cords stuck beneath.
As you can see, the Pi4 has its own PSU coming in through the base of the funnel, while the two disks and the fan all share a common 12V-3.33A brick. And yes, I admit that splitter is definitely ghetto :-)
Now a view from the other side, just to show I also got around to trimming that PCB with the on/off button :-)
The original topic if this "project" was cooling, and this pic shows an unexpected change in this regard :
In the mock-up, the fan was standing on the four brown rubber feet, a few millimetres from the base... and in the early tests, I realized this was severely restricting the air intake. Several times I had need to lift the fan/funnel assembly, holding it from the top, and each time I felt the airflow increase dramatically. Well, Duh, right ? :-)
So I scraped around and found those 4+12 plastic and felt feet, which lifted the fan base over 2cm above the base.
With the Pi4 running, I saw an immediate difference of -2 °Celsius in CPU temps.
Finally, I also added felt padding under the HDD enclosures, as the original rubber stands were really tiny.
I didn't want them to press on the cables going underneath, and hopefully the additional convection airflow will help prevent overheating.
I'm not *that* hopeful though, as the only openings on theses enclosures are at the back, and I'm not even sure there are fans behind those round ones :-)
[ Edit ] - I just found a video showing how to open the enclosures, there is no fan, just the round opening :-)