Hi Guys i had seen a load of different fan ducts on Thingiverse for Creality printers i.e cr10 cr10s ender 3 etc so thought i would test a few
all in one test print
https://www.thingiverse.com/thing:280...
semi circular fan
https://www.thingiverse.com/thing:325...
full circle fan
https://www.thingiverse.com/thing:247...
directed fan (winner)
http://www.thingiverse.com/thing:2814127