I have an upright freezer in a detached garage. My settings right now are:
F1 - 13.4C
F2 - 0.3C
F3 - 3
F4 - 0
I have a hefeweizen and a dampfbier going.
When I'm fermenting, I run two fans all the time. I have an array of computer fans on the top and a desk fan sitting in the bottom. I also generally have 10 - 12 gallons going at once. The fermentation generates most of the heat needed, so just the cold side runs.
When I'm don't have active fermentation, I just run the computer fans to save electricity. The computer fans don't quite circulate enough air to keep the temp in the chamber even.