I have my Zwift set-up in the garage.
On yesterday’s ‘endurance’ 2hr session, I didn’t need the fans, although it was down near freezing.
I quite often do as molgrips and end up with arm warmers/gloves on with the fans going as bare arms get bloody freezing when the fan is blowing in cold weather.
In terms of fans I use an 18″ pedestal fan which is on it’s last legs (the motor is dying, so can’t spin up at speeds 1 & 2). It only works on speed 3.
I also use a small fan (8″ perhaps) that normally points straight at my face, although I currently have nowhere to put that since buying a larger monitor so need to think the whole set-up through!
Not really related to the OP question, but sweat bands are great for stopping the constant drip-drip of sweat from your brow.