keezer build. put in some kegs full of water 4 thrermal mass?

[Maheel]

So i got a very cheap (but old) 200L freezer and am going to do a 4 keg keezer project

for test running it should i drop in some kegs (or fermenter) of cold water to give it some thermal mass?
thinking bag of ice in kegs + water.

Turn it on and see how it performs "power wise" before i commit to the build

thinking Koffin top style keezer and building a timber "skin" bar around it.
the skin will be built to fit a newer F/P 220L freezer just in case.

this type of thing

 

[Florian]

i would skip the ice and just juse four kegs filled with tepid water. then see how much energy it takes to cool everything down and then another measurement to see how much it uses say over a week to keep it at temp.

I'm assuming you have one of those simple energy meter thingies that you plug between outlet and freezer?

 

[Maheel]

Yeah just thinking i could help it along on the 1st cool down...

normally my full kegs are from the crash chilled ferment bar fridge so no "hot" going in

got to borrow a meter as well

 

[TheWiggman]

Once the stuff in it's cold it won't chew any more or less energy keeping it cold over time.

If you want to see how quickly it will chill something, put them in and turn it on.
If you want to see how much energy it will use, skip the above step and just turn it on.

The difference from an operational point of view is with stuff it in, it will turn on less often but run longer when it does.

 

[sponge]

I'd be tempted to put the kegs in at room temp and let them come down to temp. It will help ensure that the freezer won't play up if the demand is a little higher than normal. Might as well test it out in a 'worst-case' scenario..

 

[klangers]

Once the stuff in it's cold it won't chew any more or less energy keeping it cold over time.

If you want to see how quickly it will chill something, put them in and turn it on.
If you want to see how much energy it will use, skip the above step and just turn it on.

The difference from an operational point of view is with stuff it in, it will turn on less often but run longer when it does.

^ exactly

It won't help with temperature stability in terms of storage - as Wiggman says it will just reduce the frequency of the temperature cycling. If you want to reduce the temperature variability in the keezer then it's about modifying the controller to be more accurate which will essentially cycle the freezer more often.

Thermal mass will increase the hysteresis (lag) of the system. This works for you and against you. With 4 cold kegs in the freezer, the overall time to cool a warm one will stay the same but the initial temperature drop will be faster. Eg it will move from 25 down to 8 degrees quickly, but then as the cold kegs have warmed a bit and the time to bring it down the last little bit will take longer.