Originally Posted by HbgBill
. . . I bought a chest freezer from another brewer who has moved. It came with a Penn remote bulb controller to override the built in freezer control. . . Whether on the porch or inside (later).. how close should I expect the temp variant to be to what I set it at. There has to be a +/- swing. I'm guessing that the more liquid I put inside the better it will be.
Currently, there is nothing inside except a full glass of water with the Penn probe and another probe I use for BBQ as my check.
Having only brewed 4 brews, 2 of which had the advantage of being fermented in a temperature-controlled old chest freezer, I will give you an answer that might suffice until those more experienced than I have had a chance to read your posting and respond.
My son brought home a huge old chest freezer he got off Craigslist. It lasted a few months, but it worked great while it worked. I purchased a Ranco Two-Stage Temp Controller. I did not place the accompanying temp probe into liquid but just let it hand in the middle of the freezer. If you search the forum for info on this, you will find some debate about it. I did place a beer bottle of water on the compressor hump inside the freezer into which I placed a glass thermometer.
The freezer is in our Athens, Georgia garage which gets quite hot during the summer. I set the freezer to its lowest setting and plugged it into the "cool" outlet of the Ranco. I plugged a small space heater into the "heating" outlet of the Ranco and placed it on the compressor hump since we had purchased the freezer during a time when both heating and cooling might be needed.
In answer to your question about how wide of a swing in temp you should expect: I've read folks saying that this should be +/- 2 degrees F. Forgetting the heating cycle for now, I wanted to ferment at 66*. I set the cooling stage to 66 with a dwell (forget the exact term) of 2*. The controller will cool the freezer to 66* in the 100* garage. It shuts off when it reaches 66 - though the cold inside walls of the freezer might carry it down another degree - then it stops. It allows the freezer to slowly warm back up to 68* before it turns the freezer back on. Once the freezer had cycled for a day, it didn't cycle but for a few minutes every little while.
I occasionally checked the glass thermometer in the glass of water, and it was staying right at 66*.
I had to experiment with the Ranco so that there wasn't any overlap between the cycles. When I started it the first time, it overshot the setpoint by a degree and I heard the little space heater start up about 30 sec after the freezer stopped. At the moment, I forget the exact parameters I used.
So, my thinking is that it is you who will decide how close to the setpoint your freezer stays - and that is something that you program into your temp controller.
I hope this has helped a little.