I find it difficult to understand why anyone would want the ACC
not set to Auto.
That's what it's for, and that's the way it works best.
Set the temp to what you want, and providing it's reasonable, the fan settles down quite quickly.
At this moment, we're on holiday in Marseille. 34degC out there and with fiercly bright sunshine. No doubt the 500 drivers will have a tough time of it trying to keep cool because the 500 ACC is a bit weak in hot sunshine, so no doubt their fans are quite loud ............. or they turn it off and open the windows, and it's the traffic that'll be loud!
Home back in Cornwall in the next few days, and we'll be in our 500TA set to Auto as usual. I never even consider setting it to anything other than Auto as it's a super little system.
Greetings from sunny South of France,
Mick.