These are just simple little ducts to add a secondary fan to the Raspberry Pi 4 with the Ice Tower Cooler (original, not low profile veion). These ducts are similar, but not the same as the ducts that go iide my Mini Desktop Case. The idea of the second fan is to blow air between the bottom of the Ice Tower heatsink and the Pi's PCB, cooling the other items on the PCB and further cooling the heatsink by blowing air past the heat pipes. In my testing these extra fa can be good for 3-5 degrees depending on the fan and the quality of the fan attached to the heatsink.
Rotate the model 45 degrees counterclockwise on the X axis, put the discharge port flat on the build plate. You might want a raft for bed adhesion. It needs a tiny little bit of support under part of the discharge port. Cura will act like you need support through the iide up to the top of the flange where the fan screws on. But in my experience, those iide supports fail as often as then succeed and a few seconds with a file with clean up any artifacts from not using that support. I just put them on a raft and support from buildplate. Do these improve the Pi's cooling? In my testing, yes, they do, but not as effectively as the case (as much of the air spills out around the sides near the discharge port rather than traveling across the whole PCB. They each only take about an hour to print (at .28mm layer height, stock Cura settings on my Ender 3). These attach to the Pi and the Ice Tower with the stock Ice Tower scews. I suggest orienting the screws and standoffs so that the screws go down from the top (see the pics). This has been a fun project for me, developing and experimenting with the different funnels and different fa. I follow Chris (ExplainingCompute dot com guy) testing regiment.
Between writing the script, and doing the math in LibreOffice Calc spreadsheet, crimping the dupont connecto on different fa, scientifically testing the different orientatio and fan sized, this has turned into a very fun, very educational, time couming little project. For $100, I could see it taking up a lot of time for a 12 year old kid that's suddenly stuck at home everyday. For practical applicatio, a Pi that is cooled this well doesn't have a lot of use. The Ice Tower is enough. But it's fun to play with too much sometimes.