Those analog thermostats hat are on refrigerators or kegerators can swing 4 degrees in each direction. I'm going to use a digital Ranco to get the temp more exact, 1-2 degrees in each direction.
Would you set the differential to 1 or 2 degrees keeping in mind that a 2 degree swing would save the refrigerator a lot of wear and tear?
My Ranco seems to work like this - if I set it to 65, it turns the fridge on when the temp gets to 66 so my real temp is on the cusp of 65 and 66.
If I want 65 I set my thermometer to 64 with a 2 degree differential. Therefor when the beer gets to 66 the cooler brings it down to 64 but 90% of the fermentation is spent in the middle at 65, right where I want it.
I'm not sure if all temp controllers work this way because I've only ever used Ranco's