This is an article from 10 years ago but so far I have not seen any 3D printers actually use this.

Currently I’m designing a new toolhead for my 3D printer and I want to make the footprint as small as possible to maximize the usable print area. I’m redesigning an Ender 5 so that the bed of an Ender5Plus fits into the frame of the Ender5 and that most of the area is accessible by the nozzle. The toolhead is one obstacle.

My current toolhead has two 5015 blower fans, one on each side, and they add a significant amount of bulk to the toolhead. The fan ducts are also quite bulky.

Have any of you tried a small aquarium pump with a length of Bowden tubing and perhaps a blunt syringe tip at the end? This way you can precisely direct airflow to the plastic flow and not cool the nozzle down too much, which is unavoidable with blower fans.

I’m thinking towards those cheap 5v USB aquarium fans that you can buy for a few euros from China.