Uploaded 2 other designs before, I was using the fang type fan duct and it was working quite well, but because of the fangs I could not use a belt tensioner for the X carriage belt, I also got a silicon nozzle sock and because of that the fan duct was cooling the nozzle to much, did couple PID tunning runs but did not help, besides my X belt start to wear and needed a tensioner, so decided to design a big circular fan duct.
After 4 prototypes and testing I ended with this, it has a support so it can "hang" at outer side to the X carriage, otherwise it was hanging on that side after couple hours print.
This makes the fan duct hard to put it on but it is doable.
Also had to do a lot measuring to get it in the middle of the nozzle and the fan duct crashed in to the X stepper motor bracket, so lowered the duct and it is just going under the bracket till X reach 212mm.
Blinded 3 holes after last test to spread the air better, otherwise it was blowing to much air just below the fan.
Also posting bridging test videos so you can see how it works, the 150mm one hangs a little, but I am not sure if anyone need a 150mm bridging and it is still good with the hanging lines, see for your self.
The bridging test I have used is here: https://www.thingiverse.com/thing:2565433
Print it standing up, use custom supports, remove the supports if there is one in the channels, your printer should be able to bridge 15mm to print this, but that shouldn't be a problem for any printer.
Print with PETG or ABS, otherwise it will hang on one side after a while!
Print with: PETG or ABS