keezer: temp probe from Johnson in liquid?

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rikfxsts

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I searched for a while, and couldn't find an answer. I just got a freezer, and Johnson controller. Should I put the temp probe in some liquid? Does it matter what liquid? Should the jar of liquid be at the bottom of the freezer (cold falls), or does none of this matter?
 

scinerd3000

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the bottom is the coldest and the top is the warmest. I have around 10-13 degree difference from bottom to top in mine so I have the temp probe hung in air in the middle. The idea behind liquid bothers me because the specific heat of water or gel is higher and then temperature of it changes much slower than air temp. If the temperature inside the keezer fluctuates, i need my temp controller to respond as quickly as it need to in order to keep a constant temperature and with gel or water it will happen much slower...I do however keep a glass of water in there with a thermometer so i can check what temperature the "beer" is at
 

TwoHeadsBrewing

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I think the idea is more to keep the fridge/freezer from kicking on and off too often. Your carboys will take a long time to change temperature, even with a fairly large temperature differential between the air and beer. I have the stick-on thermometers on all my carboys, and I pay more attention to that than I do the air temp.
 

SpanishCastleAle

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the bottom is the coldest and the top is the warmest. I have around 10-13 degree difference from bottom to top in mine so I have the temp probe hung in air in the middle. The idea behind liquid bothers me because the specific heat of water or gel is higher and then temperature of it changes much slower than air temp. If the temperature inside the keezer fluctuates, i need my temp controller to respond as quickly as it need to in order to keep a constant temperature and with gel or water it will happen much slower...I do however keep a glass of water in there with a thermometer so i can check what temperature the "beer" is at
This is exactly what I do and pretty much for the same reasons. But I've seen others put the temp controller probe in gel or water so I'm curious if maybe my reasoning is wrong. Seems like ice formation in the keezer would also be worse with the controller probe in gel/water but I'm just guessing...might be the opposite.
I think the idea is more to keep the fridge/freezer from kicking on and off too often.
I keep my keezer in a warm/hot garage and it doesn't kick on/off very much so I didn't see a need to reduce it. Seems like it's almost never on when I go pull a brew. Kicking on/off less often and running longer each time is thoeretically 'better' for the compressor. I just didn't like the idea of the temperature roller-coaster the thing would be undergoing so that was one reason I specifically didn't put the controller probe in gel/water.

But the digital thermometer probe I def put in water because I don't want to see the 'temp roller-coaster'...I want to see the 'average' temp that the contents stay at. When your keezer is going through the temp cycle...it stays near the top end of the temp range longer than it stays near the bottom end. So if the air temp is cycling between say 45 F to 55 F...the contents are not at 50 F...they're warmer.
 

McKBrew

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We discussed it here a bit.

https://www.homebrewtalk.com/f35/temperature-variation-keezer-solutions-113129/

I can't find any specific threads but I know I'm not the only one to put my probe in "ice pack" gel. Having something that maintains a more steady temperature should prevent the freezer from cycling as much. I'm also looking at building a fan/blower like the ones posted in my thread to move air around.
 

SpanishCastleAle

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McKBrew,
I agree it will cycle less often and run longer when it does kick on. And this should be better for the compressor. My concern (just intuitively...nothing to back it up though) would be that the temp swings are a bit too big and also that it might lead to excessive ice formation.

It may be dependant on other things. I just looked and the newer JC controllers have a 3.5 degree F differential...maybe the older ones have a larger differential and that might make them a poor choice for the gel/water. I also would think how full the keezer is would affect it...the fuller the keezer the less cycling it will do.

I also know that if you run most of that capillary tubing (the tubing between the bulb and the controller) outside of your keezer that the ambient air temp will affect your keezer temp. As the ambient air gets warmer...the keezer gets cooler. Which makes perfect sense when you think about it.
 

McKBrew

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I have one of the digital Ranco controllers with a differential that can be set between 1 and 5 degrees. I keep mine at a two degree differential with the set point at 38 degrees and as of two days ago my probe has been in the gel.

Without spending time to log temperatures on a certain interval I can't be sure that it is any more effective than before. Just as a quick observation, it does seem that every time I go in there, the temperature is at 38 degrees. As far as exposed tubing outside the keezer, I have less than one foot.

Additionally I have noticed nothing different in regards to ice formation or moisture. It's about the same (not much, but I need to get some damp rid).

As I said, I think the only way to validate this data would be if I had the time to keep a log every couple of hours or so. I do know that things will probably be different in the summer. Right now the ambient temperature in my garage (depending on whether or not the heater is on in there) varies between 55-70 degrees. In the summer I anticipate it will be a lot warmer. (70-80 degrees plus depending on outdoor temperature). I have no problem heating my garage, but cooling it will be a different animal.

I do know that I am going to put a fan in there. Even with 10' lines I've noticed way more foam in my beer than when it was in the refrigerator. I think the temperature differential between the top and the bottom makes a big difference.
 

scinerd3000

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I do know that I am going to put a fan in there. Even with 10' lines I've noticed way more foam in my beer than when it was in the refrigerator. I think the temperature differential between the top and the bottom makes a big difference.
having a small fan in there is a great idea and i know many who use it....

as for the gel, your forgetting you can set the varience on the controller. If you dont want the compressor to go on and off alot, then set the varience bigger. I have mine set at around 45 with +/- 4 degrees. Thats an 8 degree difference and it keeps my compressor from kicking on too often without gel and is just right to keep ice from forming on the bottom. In the end it wouldnt be the end of the world
 
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