I just got done converting a mini fridge in to a fermentation chamber and ordered a Johnson Control A19AAT-2C Freezer Temperature Controller from Amazon. What I want to know is if the temp is set to 62° and the ambient temp in the room is say 55° will this be a problem?
What Chris7687 said, It is far form the most efficient setup but it will work. An ideal setup would be a controller with both a heat and a cool set of contacts but its on such a small scale it will work ether way.
I control my ferm chamber with a Partlow 1160. That particular controller has two sets of contacts, one when the temp is above setpoint, the other for when the temp is below setpoint. One turns on the compressor, the other turns on a light bulb.