I really like the Neptune 2 but the stock cooling fan was inadequate for high-temperature filaments. The stock fan produces great results with standard PLA, but the second I tried some of my favorite silk filaments, bigger fans were going to be necessary.
Using two fans means the flow from each port is exactly the same, so there should be a good symmetrical part cooling.
The nice part about having a couple of big fans is that you can run them at low speeds and produce plenty of airflow while making very little noise.
I have included two variants. One model has a mount for the BLTouch and one does not. If you decide to install a BLTouch, you will need to change your printer's firmware. The firmware is available on the Elegoo website in the support section. The offset is +55mm X and -5mm Y. See the photos for further details.
A detailed parts list, along with links to suppliers and additional design details, is available here. https://codemonkeyzero.com/elegoo-neptune-2-fan-upgrade-with-dual-fans/
Be sure to use the silicone sock on your hotend block. It will protect the air ducts from direct heat exposure.
There is a newer design available here. https://www.printables.com/model/168422-elegoo-neptune-2-hotend-5015-fans-with-dial-indica
The author marked this model as their own original creation. Imported from Thingiverse.