Does anybody have experience with Ranco temperature controls? I bought one and have it in my chest freezer. I'm fermenting a pale ale and have it set to 75 degrees. I went down to check on today and noticed it was down to 66 degrees. I double checked the thermo and it was definitely set correctly. Any ideas? Does only the probe go into the freezer? Does the probe need to be suspended? The instruction manual that came with this sucks. For the record it does go back up to 75 but that alot of variance for a beer that will be fermenting for a few weeks if it happens every day.
Temp control for chest freezer
- Thread starter sanibel14
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What temperature was your beer when you put it in the freezer? Where was the probe relative to the carboy?
If the beer was considerably over 75 degrees, when placed in the freezer, the freezer will cycle for a long time causing a massive over shoot of your desired temperature. Unless you have a two stage controller and a heat source, the Ranco has no way to heat the chest freezer back up. So you'll just have to wait it out. If I ever can't chill my wort to my desired fermentation temp. I monitor the freezer temp. closely with the probe attached to my carboy or in my thermowell on my big fermentor. When the temperature gets close to the desired, I put two gallons of warm water in there to help dampen the over shoot.
If the beer was considerably over 75 degrees, when placed in the freezer, the freezer will cycle for a long time causing a massive over shoot of your desired temperature. Unless you have a two stage controller and a heat source, the Ranco has no way to heat the chest freezer back up. So you'll just have to wait it out. If I ever can't chill my wort to my desired fermentation temp. I monitor the freezer temp. closely with the probe attached to my carboy or in my thermowell on my big fermentor. When the temperature gets close to the desired, I put two gallons of warm water in there to help dampen the over shoot.
Overshoot is a problem, but you should be able to overcome it. The location of your probe does matter a lot. I would recommend placing it at the bottom, to 1/3 the way up the keezer. I'm not familiar with the Ranco, but I bet it has a differential setting on it if it's anything like a Johnson Controls temp control. This allows you to set the hysteresis around the set point. the control won't turn the compressor on and off at 75 degrees as this would cause short cycling and prematurely burn out the freezer. Find this setting in the menu and set around 2-3 degrees to keep you temp more constant. This will make the control turn on the compressor at say 76 degrees, and off around 74 degrees (depending upon how this specific control works).
Are you sure you want to ferment your ale at 75? One of the main benefits of brewing in a chamber is being to get into optimal brewing temps and 75 is pretty high for an ale. Also the variance can definitely be set set but the freezer temp will still drop below your set temp since it continues to cool after it turns off. Check the manual for how to set it. The temp swings in the freezer are not representative of the temp swings in your beer that has a large mass. The beer will take on an average temp and have much smaller changes.
One more note. If you can't monitor your beer to prevent the overshoots, when using wort above desired temp, don't place the probe of the carboy/fermentor. This won't cool your wort as quickly as possible, but will prevent the over shoot. You loose some of the benefits of temp control as the wort sitting in an ambient temp that is exactly what you want will take a while to equalize.
