ETC Temp Control Two Stage Programming Help!

I have a chest freezer in the garage I want to use as a fermentation chamber. I have a small space heater I am goign to put in there to warm it up and of course the freezer condenser will cool it down.

I got this 2 stage ETC electronic temp control but I'm a little confused by the directions on how to program it.

It says to set Stage 1 and Stage 2. Stage 1 I will set for cooling (C1) (Plug freezer into Stage 1)
I want the temp to stay around 68-70 so the The stage 1 setpoint (S1) I will set to 68 degrees. The differential for stage 1 is what confuses me (DIF 1). Is that the plus temp I will allow before the freezer kicks on? So if I set that at 2 it will kick on the freezer when the inside temp gets above 70 degrees?

For Stage 2 I will set it for heating (H2) (Plug space heater into S2) The stage 2 setpoint (S2) should also be 68 degrees? Is the differential 2 (DIF 2) also need to be at 2? What means if it drops to 66 the heat will kick on?

What temps and differentials have you all used for regular ale fermentation. Most yeasts seem to like 65 to 70 degrees temp.

does this sound correct?

 

Ouch no comments? I did a little reading on some other forums and one I found said to set the C1 a degree below optimal temp with a differential of 3. then set the H2 temp a degree above optimal and a differential of 3.

What temp range would that give me from 68? +- 6?