Kegarator Cooling

Exactly how are you arriving at these temperatures? (Hint: The best way to tell the real temperature is to put a glass of water in the keg box next to the keg with a thermometer in it)

 

The temp inside the kegerator will vary by a few degrees as the compressor cycles on and off. Three degrees is certainly not an eyebrow raiser. The wider the range, the fewer the on/off cycles, lightening the wear and tear on the compressor somewhat (starting the motor is relatively stressful). The thermal mass of the beer is such that its temp will stay pretty constant around the middle of kegerator's range. While I've never measured it, I would be surprised if the beer's temp varied by more than a degree or so - probably not enough to notice it. FWIW, your kitchen fridge behaves much the same way, but the milk always tastes fine.

 

The temp in a glass of water will not be the same as the beer temp or the chamber temp.

 

+1. This is the right answer.

 

True, but it's a more meaningful temp than the air temp measured after opening the kegerator door. The problem is that when you open the door, all the cold air falls out and is replaced, fairly quickly, by room temperature air (I'm assuming a vertical door - this would not be the case with a chest freezer, for example). A glass of water will not warm so quickly and would more accurately reflect the air temp inside the kegerator, which would indirectly, though with a reasonable degree of confidence, reflect the temp of the beer. Obviously, not exactly the same as taking the temp of the beer, itself, but far more practical, and close enough for this purpose.

 

Replace the Bud Light with Coors Light and your fridge will stay as cold as possible all the time.

 

I agree with this. But I use internal thermometers (probes) with external readouts, so I don't have to open the door. I was assuming OP was reading a display built in to the outside of his kegerator, in which case the key is to determine what the average temp over time is, and henceforth ignore the swings. But I would not open the door to take a chamber temp reading.

 

Generally the places that most prove the temp of their coolers use a thermometer in glycerine instead of water because glycerine does not evaperate. the temp of a keg of beer depends on how long it has been in the cooler. I have seen it take 24 hours for the beer at the center of the keg to reach the cooler temp.
I fix glycol beer systems (and coolers) for a living.

 

rather than a glass of water, I would put a 5 gallon bucket of water in there for 24-48 hours and see what temperature that maintains. It's more reflective of what a 5 gallon container of beer (corney/sixtel) will maintain than a glass of water, IMO. A kegerator does not always have a uniform internal temperature, depending on how well air is or isn't circulated.

 

I have an edgestar kegerator. It wouldnot cool down but to 50-55 F. I removed thermostat probe tip from cooling plate. by doing this it ran almost 24/7, thereby getting too cold(freezing water in the glass). I looked into getting a Johnson Control external thermostat(about $75-80), then a stroke of genius come to me. I purchased a programmable outlet timer. It took some tinkering, but now I cycle on 4 hours, off 2 hours. Temp tays between 38-41 degrees. problem solved.

 

...and as a result, you have 4 defrost cycles daily! Well done!