I got a Core One with the advanced filtration system. I also got an exhaust hose which connects to outside. I want to use that to reduce smell and fumes inside.
The fan situation is a bit weird in my opinion. With the filtration system you got some options to either always run it or only for certain filaments. This is configured in the printer menu only. Afaik this is not possible via G-Code nor PrusaConnect/PrusaLink. Via G-Code you can set a fixed speed or leave it at auto. Now way to control auto/temperature logic. Also there seems to be zero telemetry (i.e. if its running at all or at which speed). Since the fan is rather quiet its sometimes hard to tell.
I personally removed the filtration system and switched to an exhaust duct which blows outside. I did not find a way to connect this to the filtration system so I am back with the case fans. Those also do not seem to have any telemetry but you can hear and see if they run. Those do not expose the same logic as the filtration fan. They can be either temperature controlled or always on at a certain speed (either via menu or G-Code). Personally I would like to have temperature control with a minimum fan speed (i.e. at least 5% to get negative pressure).
So currently I have to set a constant speed to the fan to maintain negative pressure. This is suboptimal to maintain chamber temperature. It works ok but requires some tuning. As a workaround I use Octoprint to change the fan speed during the print (via G-Code). Menu would work as well but nothing remote.
How do you guys connect your exhausts hoses? How do you control the fan? Do you use it together with the advanced filtration system? Or with an auxiliary fan?