[DrewG]

I wasn't planning on having to ferment in my fridge, let alone battle mosquitoes during mid-march, but evidently high 70's and low 80's are here to stay for a while in Michigan.

I have a ranco 2 stage and a ferm wrap, and my 80/- is getting warmer than I wanted, although it is conveniently at day 5 and  while i was planning on a diacetly rest I don't want it going above 69 or 70 (65 is the desired ferm temp for this recipe, i was going to bump it to 68 for the d-rest) So...I need to chuck the whole works in the fridge and I'm unsure what I need to set my heat, cool and buffer numbers at to hold at 68. Thanks in advance

[zorch]

If you have the temp sensor taped to the side of your fermentation vessel (or are using a thermowell), and are therefore measuring the actual beer temperature,  you should be fine just using 68 degrees as your set point for both heating and cooling with the minimum 1 degree differential.

If you are forced for some reason to let the temp probe hang in space (and are therefore measuring the ambient temp in the fridge),   I would still use 68 as your set point.  But you'll want to set your _cooling_ differential to 3 or 4 degrees.    Keep the heat at 1 degree.

The only reason for the 3-4 degree differential when cooling is to avoid short-cycling your compressor.   If you are measuring the beer temp, this is really not an issue - Beer is still mostly water, and takes a long time to change temperature, so you don't have to worry about this short cycle issue.

[DrewG]

Sensor is in a thermowell, so I'll set both sides to 68 with 1 degree differential. Thanks zorch

[ccfoo242]

EDIT: I just realized you were talking 1 degree on the heat side, just ignore this post. 

Sensor is in a thermowell, so I'll set both sides to 68 with 1 degree differential. Thanks zorch

I don't have a Ranco so this advice might not be worth a crap, but when I set mine to 1 degree it would occasionally cycle the freezer for about a second then shut it off.  The temp reading would sometimes flip back and forth from, say, 67 to 68 then back to 67 as it was warming up.  I switched to a 2 degree swing and it solved than problem. When I set to 67 it will go down to 67.9 then up to 69.0 then back down, effectively 68. Stupid but it works. 

I have this controller: http://www.amazon.com/gp/product/B0057APQIY/ref=oh_o04_s00_i00_details

Anyway, just thought I would chime in just in case.

[dcbc]

I have a Ranco dual stage with the probe under some insulation on the side of a stainless 15 gallon corny keg.  I set my cooling temp to whatever my desired fermentation temp is and the heating temp at one degree below that.  I have a 1 degree variable on both temps.  There is very little swing and no cycling of the chest freezer.  I use a heating pad in the freezer as my heat source.