Johnson Controller

[Jensen]

The thermostat is going out on my serving keggerator (4kegs in a fridge), and I hooked up an old Johnson Controller to it and it seems to be working fine so far. What is the best solution to put the controller bulb in? I have it in a 1litre water bottle with just water in it for now. I would rather measure a liquid temp in the fridge as opposed to just ambient air temp. Is this the right thinking with this type of configuration or am I going to just corrode the bulb prematurely?

[klickcue]

I doubt that you will notice a difference from leaving the probe in air or a water bath. The cornies will hold the temperature once everything is stable.

Now if you get a lot of refreshments and fan the door, you might notice a little more cycling of the compressor on and off

Just keep the wife out or give her a giant glass and you will be fine.

[Greenblood]

I remember Shane using a Whitelabs yeast vial. He put a thermowell through the cap, cut open a cold pack and squeezed it into the vial, then put the lid on, and the probe into the thermowell. He claimed he noticed a decrease in cycling. I like the compact design, but I do wonder if the gel is the best medium for the job since it is made to retain temp for extended periods of time. It seems to me that filling it with water would allow the probe to record more accurate temp, while still avoiding swings/cycling from opening the door or the fan running. You might try both, it would be a cheap experiment.

[Blktre]

I remember Shane using a Whitelabs yeast vial. He put a thermowell through the cap, cut open a cold pack and squeezed it into the vial, then put the lid on, and the probe into the thermowell. He claimed he noticed a decrease in cycling. I like the compact design, but I do wonder if the gel is the best medium for the job since it is made to retain temp for extended periods of time. It seems to me that filling it with water would allow the probe to record more accurate temp, while still avoiding swings/cycling from opening the door or the fan running. You might try both, it would be a cheap experiment.

Ive been using Gel since i built my walkin. Works like a dream. Back when i was selling those SS welded Thermowells, i made some that were short enough to fit with the WL Vial. The same Thermowell Shane uses.

Fwiw, water will evaporate over time and always required topping it up. It got stinky too unless i kept changing it out. The gel better matches a larger volume such as what is in a keg or conditioning carboy. And that is what you want to monitor. You will have no freeze up's (if used with a AC Unit), less, shorter cycles of the compressor, and takes up a very small amount of space. Before the gel, i used a thermowell and water. It worked, but required more maintenance and gained temp to fast which showed in my compressor cycles. I'm not arguing that water doesn't work at all, my experience just shows the gel works better. Water is tons better than measuring ambient air inside the box. That is a total waste of energy and causes other problems on top of that.

I replied at BB on your post, but here is the follow up to your other question....I have no clue if gel will effect copper and make the greenies. But i do know that digital temp controllers have more setting options, are more accurate, and just overall better for fine tuning temps. Analog's imo, work better for a kegerator where you really don't care about a few degrees.

[Jdl973]

I also am using the "guts" of a gel back. Put it in a mason jar, cut a hole in a lid and jammed the prob into it. I am using a Renco for my walk-in and the prob is plastic, so corrosion is not an issue. Works like a charm and as Andi said, helps reduce the cycles on the AC.

Jason

[Melonmon]

Just keep the wife out or give her a giant glass and you will be fine.

Hey--I resemble that remark!