Keezer Temp Questions

[WolfieBrew]

What's the ideal temperature differential for a Keezer thermostat? I have a Ranco Digital and the Keezer is empty but I have been testing the settings. I have tried 40° at 4° diff and 38° at 4° diff and the compressor seems to cut off for 15 minutes consistently. I was just curious what other brewers are experiencing. I was curious if having a bunch of cold kegs inside helps hold a temperature longer.

 

[Quaffer]

I was curious if having a bunch of cold kegs inside helps hold a temperature longer.

Oh, yes, definitely. I have a 1 degree hysteresis on my Love controller. I also have the probe in a plastic drinking glass with 1.5" or so of water.

 

[WolfieBrew]

I have a 1 degree hysteresis on my Love controller.

So when your setup gets to the desired temperature, how much down time does your rig typically see between cooling cycles at 1 degree? I guess this really doesn't matter, but with my freezer having quite a bit of age, I am worried that the more it cycles on and off, the harder it will be on the freezer. Is cycling on and off considered hard on the freezer?

 

[BrewMoreBeers]

Freezer compressors are pretty well built, that is why we use them. Mine cycles more than I would like, but the noise bothers me more than concern for the compressor.

 

[Quaffer]

So when your setup gets to the desired temperature, how much down time does your rig typically see between cooling cycles at 1 degree? I guess this really doesn't matter, but with my freezer having quite a bit of age, I am worried that the more it cycles on and off, the harder it will be on the freezer. Is cycling on and off considered hard on the freezer?

You are right about cycling often is hard on a freezer.

When my freezer shuts off, there is still a lot of freon in the pipes and the temperature keeps dropping another two or three degrees, so the real hysteresis is larger than one degree. I have not timed it, but I think it may run once every one or two hours. I will try to pay attention and time it. Problem is that I do not often sit there by the TV and the keezer, I am planning or building an electric brewery so my leisure time is all booked up. Oh yes, reading and writing on this forum as well.

 

[Quaffer]

So when your setup gets to the desired temperature, how much down time does your rig typically see between cooling cycles at 1 degree? I guess this really doesn't matter, but with my freezer having quite a bit of age, I am worried that the more it cycles on and off, the harder it will be on the freezer. Is cycling on and off considered hard on the freezer?

I timed my keezer tonight. As the temperature reached 44 degrees the compressor started. This was ar 10:12PM. At 10:22 the temperature has dropped to 43 degrees and the compressor stops. It had run for 10 minutes then. The temperature kept dropping, slowly, until it reached 41 degrees at the lowest. It sat there for a while and then turned around. It seemed to hover at 43 degrees forever as I am waiting for it to start so I can wrap this up and go to bed. There, finally, at 12:42AM the compressor starts again.

So, the total cycle is 2.5 hours (150 minutes), of which it ran for 10 minutes. I have four kegs in there so there is plenty of thermal mass to hold the temperature.

A few things to think about:

• It is important not to have air leaks around the lid seal, especially if you have a fan in there to stir things up.
• The collar needs to be insulated to prevent short cycling.
• If the fan in the keezer is too powerful it will heat the air quickly. Every Watt that goes up the wires to the fan will be dissipated as heat in the keezer. It is like having a small lightbulb on in there. I backed off on the drive voltage for the fan until I thought it made just the right amount of quiet breeze. It is a 12V 120mm computer fan which I run at 7.2V. I also only run the fan when the compressor runs, eliminating a lot of unecessary heat.

 

[WAORGANY]

I have a Johnson controller on mine have 6-8 kegs and some bottles in the 14 cu ft chest freezer in an unheated room and keep the temp set at 38 degrees..it rarley cycles...winter or summer...always have cold beer. My collar is not insulated, I think that it might also have to do with the brand and age of the freezer as well. Mine is a new Fridgadaire that I got at Lowe's. A;; the best

 

[WolfieBrew]

WOW, the compressor only ran for 10 minutes during a 2.5 HR cycle. That blows my test out the water. I might try to put a few carboys of water in there while I'm waiting on my brew and test again. This makes me very curious to hear the results who are willing to test and monitor their environment for a few hours...

 

[Bottenbrew]

What you have to keep in mind is that the amount of heat to raise the air in your empty freezer a couple of degrees is significantly less than the amount of heat needed to raise the temp in a freezer containing 4 full beer kegs. Short of knowing the math on it, I don't think there is a way to "test" what your freezer will do when it is full.

 

[Quaffer]

What you have to keep in mind is that the amount of heat to raise the air in your empty freezer a couple of degrees is significantly less than the amount of heat needed to raise the temp in a freezer containing 4 full beer kegs. Short of knowing the math on it, I don't think there is a way to "test" what your freezer will do when it is full.

The cycle time will be shorter with an empty freezer, but so will the run-time. The duty cycle (on-time / cycle time) would remain the same, full or empty, because the loss of heat over time is the same.

If the compressor is old and worn, the on-time will be longer because the cooling power is reduced. It would not affect the off-time at all.

If the insulation is damaged, wet, or just cheap, then the off-time will be shorter.

 

[lotbfan]

my UN-collared keezer runs a ranco and is set to 38 with a 2 degree differential, and today it ran 3 times for about 5 minutes each between 8am when I woke up and now as I am going to bed. I should be making a collar within the next 2 weeks (no faucets yet, so no hurry) and it will be interesting to see how much that changes.

fwiw my ambient temp is about 68 in my living room.

 

[WolfieBrew]

I have four kegs in there so there is plenty of thermal mass to hold the temperature.

I was watching a movie last night and decided to time my keezer now that I have some thermal mass inside. I have a corny keg, a square cooler with san water, and a few empty apple juice jugs. Obviously, my results were much different than when the keezer was empty. When the compressor kicked on at 42 degrees, it ran for 40 minutes and then turned off at 40 but immediately fell to 39. The compressor remained off for almost 2 hours exactly before cycling back on. It is a much older model freezer so I would expect it to be a little less efficient but I didn't expect 40 min. I am eager to see what the cycling is like when I have it packed full of kegs.