Frozen Keg - Johnson Controls A419ABG-3C

[jarrodaden]

I have made a keezer from a 7 cubic foot chest freezer. I ran the keezer empty for about one week to make sure the temps were ok. With SP = 45 degrees, there were some small swings in temperature, but the temperature never went below 40 degrees.

After the testing, I put one keg inside. No problems for the first few days. Last night I went to get a beer and everything was frozen.

Can someone help me understand what I have done wrong?

Here is the list of all of my settings

SP = 45
DIF = 1
ASD = 5

All other settings are the factory ones. I did not change them.

 

[ScottG58]

Where do you have the sensor?

 

[jarrodaden]

The temperature sensor was inside the lid, vertically even with the wood collar that I built but not in direct contact with the sides of the keezer.

 

[moviebrain]

I place my sensor near the bottom of my keezer usually taped to the side of my keg closest to the cooling coils. That way I'm measuring the temp of the keg closest to where it is served from.

If you had some sort of fan or air movement to bring the cold air from the bottom to your collar and sensor it'd be better.

 

[Homercidal]

Did you make sure that the unit was set to cool, not heat? What about cut-off, cut-in?

That is what I dislike about the Johnson units. They are built well, but they are a PITA to change those settings and they are single stage. They are built more for industrial use where they will really only see one kind of environment, and rarely need to be changed.

 

[jarrodaden]

Can I get some input on putting the probe in a bottle of water vs in the open air?

When I tried the bottle of water, it took the water way too long to cool / warm and I found there were bigger swings in the cooling / warming.

 

[rgauthier20420]

If you put the sensor is a larger mass (i.e. a bottle of water), your temps swings should be less and it also should cut down on the run time for the compressor.

Your lines likely froze because you were measuring the temp of the air at the top of the keezer. The top will be the warmest part as the cold air will go to the bottom. Not to mention, your coils start usually a couple inches down from the usual top of the chest freezer. Add the collar in there and your not getting anywhere close to the accurate temp in there. Put a 2 liter of water with the sensor in it (not all the way because you don't want to ruin it if it's not water proof) and that should even out the temps.

 

[ScottG58]

Try taping the sensor to the keg and tape bubble wrap on top of it .

 

[day_trippr]

Dunking the probe in water you'll be long-term testing the ability of the probe to withstand water ingress. And considering most probes are not actually rated as waterproof, that's a test that will most likely fail, eventually.

And, fwiw, bubble wrap is better than the folded paper towel that some use, but an inch thick piece of closed cell foam scavenged from random product packaging is a lot more effective, durable, and easier to use...

Cheers!

 

[ram5ey]

And, fwiw, bubble wrap is better than the folded paper towel that some use, but an inch thick piece of closed cell foam scavenged from random product packaging is a lot more effective, durable, and easier to use...

Cheers!

This

 

[moviebrain]

Your initial temp swing, keg vs ambient in the cooler, will be greater. But when the keg makes it to the target temp, with a 1F differential, those swings will be almost non-existent going forward.

 

[pulfson]

To the side of each one of my kegs I have taped a gel pack, the type that comes frozen when I get yeast shipped to me. This has worked great so far, + that I get them for free if I ask my LHBS when I buy yeast.

 

[SpeedYellow]

Why would you put the probe in a bottle of liquid when you could simply increase the differential on the thermostat? Would effectively do the same thing.

 

[day_trippr]

Why would you put the probe in a bottle of liquid when you could simply increase the differential on the thermostat? Would effectively do the same thing.

You're going to have to explain how you arrived at that conclusion...so we can poke holes in it...

Cheers!

 

[SpeedYellow]

You're going to have to explain how you arrived at that conclusion...so we can poke holes in it...

Cheers!

I'll assume your serious, and explain. Lets say you change nothing except you put the probe in a water bottle or gel pack. By observation you'll find the fridge doesn't come on as often. So since the fridge isn't coming on as often, obviously the air inside is warming up more than it used to; it's just that you've insulted the probe from that warmer air. So you effectively just increased the differential.

 

[day_trippr]

I was serious - and I still don't see how that is superior to measuring the actual beer temperature - either via a thermowelled probe or a probe coupled to the outside of a keg/fermentation vessel and well insulated from external influence. Either method allows a tight differential to be used, and provides massive hysteresis so my compressors cycle infrequently.

That is how my fermentation fridge, my cold conditioning and carbing fridge, and my keezer all operate.
My fermentations are dead nuts where I want them to be, as is my finished beer.

Controlling air per se isn't my goal. Controlling beer is.

The probe dunking in a small vessel of water provides hysteresis - much less than a 5 gallon vessel filled with beer, but way more than a probe hanging in free air. So it's a half step in the right direction. The fact that the air temperature may be all over the place is unimportant. The product is important.

Cheers!

 

[rgauthier20420]

To follow my own notes about using the bottle of liquid, you should just mess with the built in thermostat of the chest freezer. Here's a nice long thread of how to do it

https://www.homebrewtalk.com/f51/gu...mostat-32f-eliminate-external-control-249612/

This is exactly what I did, and my keezer stays at 40 degrees +/- 2 degrees and I don't have anything else hanging outside of the keezer now. Also, I've freed up my Johnson control for a ferm chamber down the road. The screw is relatively easy to find on most chest freezers.

Good luck.

 

[SpeedYellow]

Day_trippr, I agree with everything you just said. But you didn't address my statement that using a water bottle is the same as increasing the differential. I'm not suggesting increasing the differential as some general course of action, just pointing out that it's silly to immerse the probe when you can do the same thing electronically, if your needs call for it.