I find it strange that the Nozzle blower is sucking in hot air from the heated bed. Turning it upside down and in combination with my Bowden Tube Blower, it will get in enough cool air that was flowing out of the extruder. For this the fan shroud needed extension. Also an updated fan support is needed, Optional but good is an updated extruder cover with a closed verturi hole, a removed arm and a "bite" out of the front for better air flow (when using a blower for the extruder).
The original extruder is a ButterworthDesign (https://shop.prusa3d.com/forum/user-mods-octoprint-enclosures-nozzles--f65/modified-c1-r4-mk3s-parts-better-filament-path-and-t28334.html#p133592)