How long should six kegs take to chill?

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mtb

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Six full room temperature kegs were placed inside a sweet new keezer, ambient room temp at the moment is ~24C. Is it of any concern if it's been running for 36hrs and temp has reached only 13C? The measurement probe is immersed in a 4L keg full of water. The compressor is running constantly and it was tested before purchase.
 
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Six kegs = 300 kg = 1.2 MJ / oC heat capacity*.

If your freezer is 150 watts and has a COP of 1.5** it can remove 225J / second which is 0.81 MJ / hour, so you would expect the temperature to decline by 0.675 oC / hour under perfect conditions.

You report approximately 0.3 oC / hr which is a little under 50% of theoretical maximum, sounds about par for the course to me.


* Typically beer is a little lower than water (4.18 kJ / kg / oC) due to the presence of ethanol and sugars. 4 is a reasonable round figure.

** I don't know exact COP figures for domestic freezers but this appears to be typical of small commercial freezers.
 
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Thank f#$k for that. LC, I am always appreciative of the scientific approach, more so now because I don't think I could handle a second large scale purchase falling through on me - especially given I was very careful about this one. It's very pretty!

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@Lyrebird_Cycles , these are 19L kegs. Have your calculations above assumed they are larger? I'm just seeing six kegs = 300kg which implies 50kg per keg
 
Does the cladding illustrated by any chance impede free air flow around the external heat exchanger coils? If so that will dramatically decrease efficiency.
 
@Lyrebird_Cycles , these are 19L kegs. Have your calculations above assumed they are larger? I'm just seeing six kegs = 300kg which implies 50kg per keg

You said kegs, so I assumed industry standard kegs, 50 litres each. If you meant cornys, divide the above by 2.5.
 
Does the cladding illustrated by any chance impede free air flow around the external heat exchanger coils? If so that will dramatically decrease efficiency.
Nope, cladding doesn't interfere there. Compressor vent and coils on the rear are unimpeded.
 
I ran a freezer with an external coil recently to chill down a few kegs from 30ish degrees to fridge temps. Didn't take 36 hours but did take a lot longer than I thought.

Wait til it achieves temperature and then keep an eye on it.
 
Nope, cladding doesn't interfere there. Compressor vent and coils on the rear are unimpeded.

Are you sure on this? A lot of chest freezers disperse their heat through all sides.
 
Also, I see an alarming disproportionality between the number of kegs and taps?

Keezer looks good though, as does the wall behind it. Did you do the wall yourself?
 
I have plans for the taps. The keezer will actually fit eight kegs and I plan to use that capacity well - a new font setup will be on the cards soon but because I won't be chilling the font I need to consider options. Will definitely seek out some threads for inspiration.

The wall came with the house - not bad eh?
 
6 kegs to chill at once with 2 taps at this stage. Hindsight is a good thing but I’d have put 2 in first for the taps and added a keg or two each night after drinks until all chilled. 6 x 19l at once is a big job.

Could you have sped up the process up by starting off with the freezer acting as a freezer, monitor temp then reset to your desired temp.
 
6 kegs to chill at once with 2 taps at this stage. Hindsight is a good thing but I’d have put 2 in first for the taps and added a keg or two each night after drinks until all chilled. 6 x 19l at once is a big job.
Could you have sped up the process up by starting off with the freezer acting as a freezer, monitor temp then reset to your desired temp.
The other reason I stocked it up with 6x kegs was to get them out of the Canberra heat. I was happy to wait an extra few days to chill if it meant I wasn't subjecting any to wild temp fluctuations.
After returning from an exhausting gold prospecting trip, I'm happy to find them now at 8C. Just a few more degrees..
 
“Canberra heat” ha, hot wind and bull shit from parliament more likely.
It's been quite nice here lately, went to Melbourne a couple of weeks ago and wished we'd stayed home for the nice sunshine.

Mtb, where did you go prospecting? Just curious
 
Mtb, where did you go prospecting? Just curious
Macphersons Swamp Creek out via Wee Jasper Rd. Takings weren't great, mainly thanks to my engineer friend's trommel kicking the bucket.. but I found a nice blue/green sapphire for the missus and weather was fecking brilliant
 
Does the sapphire to the missus give you credits for more stainless steel goodies or paying off pre purchases?
 

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