issues with cooling chest freezer down with external control

[tconnolly1120]

Hey all,

Just kegged my first beer a few days ago and purchased a chest freezer to keep it in (also to use as a fermentation chamber at different times). I purchased a Johnson Controls A19AAT-2C Freezer Temperature Controller to regulate the temperature and hopefully keep it around 40 F. I've had the Chest Freezer plugged into the Controller for 4 days now and the Chest Freezer has yet to go below 60 F. I followed the exact instructions:

1. Plug the Chest Freezer into the female portion of the controller plug and plug the male portion into the wall.
2. Put the coil into the chest freezer.
3. Put the chest freezer to the coldest temperature on the on-board thermostat.

I have to keep adjusting the external set point lower and lower to get the freezer to turn back on. I have the external set point at 38 F now and the freezer is still at 60 F. Every time I lower the external temp controller by 5 F the freezer kicks back on for about 5 minutes and then shuts back off.

This has effectively led to the carbonating of my beer to take forever.

What could be the problem here? The chest freezer is brand new.

 

[day_trippr]

Even money says you have the sensor bulb dangling in the air. Yes?
If so, that's not going to work well in a chest freezer, because the air will chill so rapidly the controller won't let the compressor run long enough to actually chill the beer in a reasonable time.

You're trying to hold beer at a set point, so pin the sensor bulb to the side of a keg near the bottom, with a good insulator over it. I use velcro straps and ~ 4" square pad of 1" thick closed cell foam scavenged from random product packaging.

Do this well and you'll be able to easily control your beer temperature...

Cheers!

 

[tconnolly1120]

Even money says you have the sensor bulb dangling in the air. Yes?
If so, that's not going to work well in a chest freezer, because the air will chill so rapidly the controller won't let the compressor run long enough to actually chill the beer in a reasonably time.

You're trying to hold beer at a set point, so pin the sensor bulb to the side of a keg near the bottom, with a good insulator over it. I use velcro straps and ~ 4" square pad of 1" thick closed cell foam scavenged from random product packaging.

Do this well and you'll be able to easily control your beer temperature...

Cheers!

You nailed it. I will definitely take the suggestion and see how it works.

Cheers!

 

[Konadog]

You can also tape your sensor over a jar of water so you don't have to keep re-tapeing it when your keg kicks.

 

[tconnolly1120]

You can also tape your sensor over a jar of water so you don't have to keep re-tapeing it when your keg kicks.

You mean just taping the sensor at the top of an open jar of water, or inside the jar?

How would putting the sensor in a full growler full of water work? I care more about the temperature of the liquid then the ambient air temp in the chest freezer. Obviously the growler of water will cool faster than a keg of 5 gallons of beer, but at least I can keep the fridge running at a constant temp and adjust lower to get my desired 40 F of beer inside the keg.

Thanks for the help guys.

 

[Morrey]

You mean just taping the sensor at the top of an open jar of water, or inside the jar?

How would putting the sensor in a full growler full of water work? I care more about the temperature of the liquid then the ambient air temp in the chest freezer. Obviously the growler of water will cool faster than a keg of 5 gallons of beer, but at least I can keep the fridge running at a constant temp and adjust lower to get my desired 40 F of beer inside the keg.

Thanks for the help guys.

Sure that will work. I took an empty 20 oz Coke bottle and filled it with the gel from a freezer pack(s) that was thawed....gel packs like they ship with yeast. Drilled a small hole in the lid for the probe, suspended probe making sure it didn't touch sides of bottle, then dabbed a bit of liquid electrical tape to seal. You get the idea.

Another way is to tape the sensor probe to the side of your fermenter/carboy/keg and cover with something to shield the probe from ambient air exposure. A neoprene beer hugger works well. Drawback is you have to tape the probe each time you move something in and move something out. With the Coke bottle/freezer gel method, it remains semi permanent.


Absolutely you are more concerned about the temps of the liquids in the freezer, and the temps of the air mass inside means very little. Also, you mentioned the growler water will chill more quickly, and while that may be true, all the liquids will come to an equilibrium point given time.

 

[Konadog]

You mean just taping the sensor at the top of an open jar of water, or inside the jar?

No, fill a jar with water and tape the sensor to the outside of the jar. Even a small jar of water won't fluctuate any where near as fast as ambient air. Then you don't need to re-tape the sensor on a keg every time one kicks. Any liquid in a bottle, can, or growler would work just the same, just be sure that the sensor is within the liquid level.

 

[tconnolly1120]

Thanks for the help guys. I read up on controlling the temp of beer in kegs and during fermentation in a few different threads and didn't realize there was so much to utilizing the ETC. I haven't changed any of the factory settings, such as cut-in or cut-off, differential, etc. I guess what I'm saying is I need to get a better handle on exactly what the ETC is accomplishing - some of these threads get really deep into the engineering aspects of it and I'm just beginning with that.

As a hypothetical, lets say I want the beer in my keg to be 42 F. I will tape the sensor (wrapped in an insulator) to the outside of a growler filled with water that will be placed next to the keg on the floor of the chest freezer. What temperature should I set my ETC to accomplish the desired 42 F of the beer? 38 F? Also, should I have it set at cut-in or cut-out when the temperature of the probe reaches 38 F? As for differential, should I have it set at say 8 or less? I don't want my freezer kicking in consistently but I do not want the beer temperature to fluctuate consistently. Obviously a change in approx 5-6 degrees temperature around the probe will not result in the temp of beer in the keg changing too much as liquid has a much higher specific gravity and takes longer for temperature swings to occur.

 

[tconnolly1120]

I just insulated the sensor with an old beer coozy I cut up and taped it shut. I then taped the sensor to a growler filled with room temp water and put it on the middle shelf in the chest freezer. I put the ETC to a desired 40 F and the freezer kicked on. The freezer only ran for about 3 minutes before shutting off again. I have two thermometers in the freezer in different locations and the coldest either one is registering is 52 F. There is no way the water in the growler has reached 40 F in 5 minutes from room temperature.

I cannot get this thing to continuously run to get to the desired temp indicated on the ETC. What could possibly be wrong?

 

[auburntsts]

Maybe the probe is bad?

 

[Morrey]

I just insulated the sensor with an old beer coozy I cut up and taped it shut. I then taped the sensor to a growler filled with room temp water and put it on the middle shelf in the chest freezer. I put the ETC to a desired 40 F and the freezer kicked on. The freezer only ran for about 3 minutes before shutting off again. I have two thermometers in the freezer in different locations and the coldest either one is registering is 52 F. There is no way the water in the growler has reached 40 F in 5 minutes from room temperature.

I cannot get this thing to continuously run to get to the desired temp indicated on the ETC. What could possibly be wrong?

Don't think your factory default settings have the hysteresis set that wide. I'd guess you have a bad unit or bad probe. A replacement may be in order, and FWIW, I use Inkbird 308's found on Amazon for $28 when they do lightening sales.

 

[day_trippr]

[...]I haven't changed any of the factory settings, such as cut-in or cut-off, differential, etc. [...]

Wait - your original post stated you were using an A19AAT-2C.
That model is totally mechanical and literally has zero user-configurable settings aside from the temperature knob. No cut-in/cut-out modes, and the differential is fixed at 2°C/3.5°F.

If that's the model you are indeed using I would agree there's something amiss with it. I would put the unit on a bench and experiment with a jar of ice water checked with a trusted thermometer, stick the bulb in it, and see if the controller "sees" the same temperature or not.

Otoh, if you actually have a digital model like the A419ABC-1 then there's always the possibility something is mis-configured...

Cheers!

 

[beernutz]

Hey all,

Just kegged my first beer a few days ago and purchased a chest freezer to keep it in (also to use as a fermentation chamber at different times). I purchased a Johnson Controls A19AAT-2C Freezer Temperature Controller to regulate the temperature and hopefully keep it around 40 F. I've had the Chest Freezer plugged into the Controller for 4 days now and the Chest Freezer has yet to go below 60 F. I followed the exact instructions:

1. Plug the Chest Freezer into the female portion of the controller plug and plug the male portion into the wall.
2. Put the coil into the chest freezer.
3. Put the chest freezer to the coldest temperature on the on-board thermostat.

I have to keep adjusting the external set point lower and lower to get the freezer to turn back on. I have the external set point at 38 F now and the freezer is still at 60 F. Every time I lower the external temp controller by 5 F the freezer kicks back on for about 5 minutes and then shuts back off.

This has effectively led to the carbonating of my beer to take forever.

What could be the problem here? The chest freezer is brand new.

I have owned one of those controllers for almost 20 years and it still works and keeps a freezer within a couple degrees of where it is set. If yours was purchased new I'd see about returning or exchanging it because mine has been rock solid forever.

I also have owned their A419 model for 4 years and I have similarly found it to be bullet proof.

Did you test the freezer without the temp controller on it to be sure it is working correctly?

 

[tconnolly1120]

Wait - your original post stated you were using an A19AAT-2C.
That model is totally mechanical and literally has zero user-configurable settings aside from the temperature knob. No cut-in/cut-out modes, and the differential is fixed at 2°C/3.5°F.

If that's the model you are indeed using I would agree there's something amiss with it. I would put the unit on a bench and experiment with a jar of ice water checked with a trusted thermometer, stick the bulb in it, and see if the controller "sees" the same temperature or not.

Otoh, if you actually have a digital model like the A419ABC-1 then there's always the possibility something is mis-configured...

Cheers!

Yep you are correct. I did not realize the ETC did not have user settings.

I'm going to test the method of utilizing the gel from the ice packs inside of a soda bottle tonight and leave it overnight to see what happens.

 

[tconnolly1120]

I have owned one of those controllers for almost 20 years and it still works and keeps a freezer within a couple degrees of where it is set. If yours was purchased new I'd see about returning or exchanging it because mine has been rock solid forever.

I also have owned their A419 model for 4 years and I have similarly found it to be bullet proof.

Did you test the freezer without the temp controller on it to be sure it is working correctly?

Yep it is a brand new ETC which I got about a week ago.

I tested the freezer without the temp controller a few weeks ago and it is definitely working correctly.

I'm going to try a few more things and report back.

Thanks for all your help guys. Cheers!

 

[Parrothead01]

This will work for serving beer, but when you are using it for fermentation, you need to tape the sensor to your fermenter

 

[estricklin]

It sounds like the controller could in fact be faulty, I'm interested in hearing your results. This shouldn't be that complicated, especially for serving beer. I have dangled my probes in the air inside, or laid them onto kegs/fermenters and have had good results.

You should do a search for "building an STC 1000 temp controller". With it, you can heat and cool, and they are super cheap to build.

 

[day_trippr]

[...]I have dangled my probes in the air inside, or laid them onto kegs/fermenters and have had good results.[...]

Refrigerator, or chest freezer?
From experience that'd work fairly well in the former, not very well in the latter, which is the case here...

Cheers!

 

[estricklin]

Refrigerator, or chest freezer?
From experience that'd work fairly well in the former, not very well in the latter, which is the case here...

Cheers!

Both, I wouldn't do it for fermentation because it's not accurate enough but for cooling kegs, it's fine. Eventually the air and beer is gonna be the same temp!

 

[day_trippr]

Perhaps, but dangling a probe in a chest freezer is going to produce short compressor cycles, even if the overall duty cycle is the same as using a well-coupled/insulated probe to a large vessel of beer.

"Hysteresis Matters"

Cheers!