Making a couple of observations.
1. I run the KPA 1500 at about a KW on lower bands and full power on higher bands. I am a long winded CW operator so generally get to fan level three during most transmissions. I let the factory default settings mange the fans.
2. That being said, there is a program out there called Fanticipator that gives the operator some fan management tools to use if the want to do things like having the funs run longer or at a minimum speed when operating.
3. My shack is on the west side of an un-airconditioned house. Lots of glass. Summer afternoons can push 80 plus degrees in the shack. I remotely located my amp in a cool area below the shack. I have USB and Ethernet cables running from the K3s to the amp. I can use the KPA 1500 utility, the Elecraft KPA 1500 remote program or Fanticipator to manage the remote amp. In the remote location, the amp runs significantly cooler and I don't have any fan noise to deal with. I like using Fanticipator for remote control because it has a small monitor footprint and, uniquely, keeps the power out and swr reading on the display so you can look at them after you transmit.
4. Personally, I find the regular Elecraft forum difficult to read. It doesn't put messages into threads like Groups or Google.