Digtal temp controller?

Hello I have a dual temp controller my ? is what a good differntial to set for the cooling an the heating … Let say I want to ferment at 60F I set the cooling to 60F an what differntial do i set it to an also what about the heating setting or do you even need heating during the summer mouths

I have mine set to .5 (half a degree).

I see no reason to have a cooling system battling a heating system. The fermentation will generate the heat inside the fridge/freezer.