Beer Temp Vs. Keezer Temp

[daytondave]

I have my keezer set at 38F using a ThermoStar Digital Temperature Controller yet the beer coming out of my keezer is 46F which is a bit too warm for my liking. The thermometer and the Theromastar have been checked and our calibrated correctly.

I'm lowering the temp of the keeser to compensate, just wondering if it is normal to have this much difference in temp or if something is wrong with my set up.

 

[mredge73]

Get some foil tape, the kind that AC guys use on duct work. This stuff will stick better and remove cleanly on the damp keg.
Tape the sensor to the keg in the center of keezer.

 

[Sdiddy84]

I took a mason jar and drilled a hole in its lid the size of my temp probe. Then I put a rubber grommet in the hole to protect the sensor and put water in the jar. Its not perfect but if the water is 38F then the beer should be 38F. I haven't actually done a temp test but it seems to be ok. My beer is nice and cold.

As a side note I keep the mason jar on the compressor shelf in the keezer which is about half way up the keezer. just in case there was any temp fluctuations from the bottom of the keezer and the top.

 

[kh54s10]

How long has the keg been in there. It seems to me that even if the probe was just sitting in the keezer, the beer would be the same temperature eventually.

As Sdiddy84 noted if the temperature probe is on the bottom of the keezer it will probably be reading colder than the actual ambient temperature at the top of the keezer. Many use a computer fan to circulate the cold air in their keezers.

 

[day_trippr]

How long has the keg been in there. It seems to me that even if the probe was just sitting in the keezer, the beer would be the same temperature eventually. [...].

Perhaps, but a dangling probe will likely pound the snot out of the compressor.
Better to tightly-couple a controller probe to a large thermal mass and take advantage of the huge hysteresis effect...

Cheers!

 

[kh54s10]

Perhaps, but a dangling probe will likely pound the snot out of the compressor.
Better to tightly-couple a controller probe to a large thermal mass and take advantage of the huge hysteresis effect...

Cheers!

Yep, but that is a different story solved by measuring the temperature of the keg and using a temperature controller that will limit the cooling cycles.

 

[day_trippr]

Yep, but that is a different story solved by measuring the temperature of the keg and using a temperature controller that will limit the cooling cycles.

I'll assume "limit the cooling cycles" was your point.
But that's actually not what happens.

The thermal mass alone assures the compressor cycle time is well beyond any "short-cycle limiter" setting.
My keezer controller tracks keg temperature the same way my ferm fridge controller tracks fermentor temperature - with a probe pinned to the side of the vessel with an inch of foam over it.

Yesterday in another thread an HBT member building a new keezer noted his empty freezer was cycling rapidly - with the controller probe hanging inside.
I posted this plot from my keezer controller showing the compressor running 1 hour on and just over 3 hours off in an ~70°F room...



Cheers!