Here's my first version of the E3D Hermes mount for the Ender 3. I might do some small teaks. Instead of the stock fan, I use a 40mm blower fan (same as the CR-10S Pro) as i feel it does a better job. It is secured to the fan with some super glue or hot glue. mount prints without supports, the blower duct might need just a little support on the curve from the build plate only.
This should also be compatible with Creality CR-10, CR-10S, CR-10 4S, CR-10 5S, CR20, Ender 5