run time keezer/kegerator

The thermal mass of the beer is such that I'd be surprised if the beer temp varied by more than one degree across cycles, and probably less. It's probably pretty stable at about 38-ish. You can verify this by taking the temp of the beer at various points during the one-hour cycle. I would probably set the differential even higher - say 6 degrees, or even 10. At some point, the beer temp will begin to fluctuate outside an acceptable range - not sure where the sweet spot is. Some would recommend putting the probe in water, but that only guarantees that the beer's temp will change (and the differential kinda, sorta accomplishes the same thing).

In terms of which is 'better' - longer cycle times or more stable beer temp - obviously, it's a compromise. Cycling on and off is among the big factors influencing motor life. That said, I, personally, have never seen a fridge or A/C fail due to a failed motor. It's always been a refrigerant issue. I don't know to what extent that's influenced by cycling.

I've never timed my freezer's cycles (and I may be wrong), but one cycle per hour doesn't sound excessive. (FWIW, I adjusted the thermostat in my keezer so I don't need an external controller).

 

I really believe you are overthinking this. i like that though, as i firmly believe this is an ideal hobby for fixing anything and everything that ain't broke.

to the point, if your beer is consistently at the temp you like and the motor is not always running then you have achieved the goal. additionally, if your duty rating is within 50% you are really really really not stressing the unit. remember that this thing is designed to keep food cold at zero F or below. so while our keezers are relatively inefficient (because it is overdesigned for the task - like commuting to work with a tractor trailer...), we can be certain that everything will be ok.
besides, if this thing works for 10 years, we buy a new one. we need to build and experiment after all, no?

my temp is set at 38 with a 4 degree dif if it matters.
Cheers.

 

My take on that is that it would then wait until the liquid, along with the beer, is at the 'wrong' temperature before reacting. Better to be proactive and react to changes in the ambient temp before it's reflected in the beer temp.

I read an article on that and decided WTH (I live to tweak!). It worked well, though I couldn't directly set it to a specific temp - I used a trial and error approach and put markings on the dial, so it's good enough, IMO. It frees up the Johnson for fermentation (I still need a freezer for that ). FWIW, I have no idea what the differential is on the internal thermostat. But, since it's not being used for fermentation, it's not all that important.

 

how long does it cycle on and off?

hell if I know. my keezer has a little orange indicator light that shines when it is on. sometimes it is on, mostly its off. I suppose the light was added because there are a lot of people like you who want to be sure everything is OK.
it's also 6 feet and cost $100. he told me his wife told him to get it the hell out of the house. I had buy it; I told my wife it was the right thing to do.

it will probably keep beer cold for 20 years.
Cheers.

 

this thing is the size of a coffin. I knew I messed up. she is a saint, God bless her.
I told the guy if it fits in the bed of my truck, i'm taking it home and asking forgiveness later. also, i'm thinking "my soon to be keezer is just shy of a walk in cooler, I win!"

so it fits with about one inch with the tailgate closed. I got home, slid it out of the pick up and lowered one end to the ground, then the other. it was all I could do to shimmy it into the garage and leave it where a car should rightfully be parked. the I waited until she found out.

I haven't had the same feeling of dread since screwing up in grade school and anticipating a report card. the keezer has not moved more than 3 feet from its original resting place. she is a saint. God bless her. every beer nerd should be so lucky. she is drinking a homebrew at the moment, too. I think i'm in the clear.
Cheers.

 

You can decrease run times by adding an accessory fan to cool the compressor. The condenser of a chest freezer is the cabinet itself, so you can't add an actual condenser fan. By wiring a fan in series with the compressor it will cool it, which will make it run less, and extend it's life. Remember refrigeration doesn't make cold air, it removes moisture, which removes heat.