Keezer Efficiency Experiment

[HOP-HEAD]

I'm not sure about any of you, but I've been curious as to the cost of operating my Keezer since it's inception. I've heard so many theoretical claims on here that they're more efficient than a freezer because they maintain a lower temp, cycle less, cycle shorter durations, etc. In addition, I've heard that a bare temp probe was less efficient than one in water or another liquid... and that insulating the collar wasn't a big deal...

Well... I finally broke down and bought one of those appliance wattage measuring devices. You plug it into an outlet, and then plug the appliance into it... measures the duration since it was reset, the kwh's since reset, current voltage draw, and even calcs the cost if you adjust the kwh/rate to match your supplier.

My initial checks will be on the average kwh that she's drawing currently, as apposed to draw of the exact same (unmodified) freezer that I happen to use in the garage for storing food. Should be interesting.

After that, I plan to test the bare probe versus submersed, as well as the affects of tightening and/or loosening the variation of the temp controller. Currently mine is set to 4°F.

Stay tuned if you're as big of a nerd as I am...

 

[Bobby_M]

My initial checks will be on the average kwh that she's drawing currently, as apposed to draw of the exact same (unmodified) freezer that I happen to use in the garage for storing food. Should be interesting.

This wouldn't be much of a correlation because the set temps are different. The delta between the conditioned space and the ambient temp is higher for the frozen food one.

 

[Catt22]

I agree with Bobby on this. I have some similar testing underway right now. The problem is that there are a lot of variables to consider. The size of the freezer, how much is in the freezer, the ambient temps, the controller set point & differential settings, the probe placement, fan vs no fan, fan continuous vs fan intermittent, insulated collar vs non-insulated etc., etc. As you can see, it gets complicated quickly. The age and condition of the freezer will also probably make a difference. As you can see, it's not as simple as it first appears.

 

[HOP-HEAD]

I agree with Bobby on this. I have some similar testing underway right now. The problem is that there are a lot of variables to consider. The size of the freezer, how much is in the freezer, the ambient temps, the controller set point & differential settings, the probe placement, fan vs no fan, fan continuous vs fan intermittent, insulated collar vs non-insulated etc., etc. As you can see, it gets complicated quickly. The age and condition of the freezer will also probably make a difference. As you can see, it's not as simple as it first appears.

Obviously there are thousands of variables... but aren't you curious as to how an energy star freezer that draws very little operates after you remove the top, build a collar, and lower the temp setting while increasing the cycling frequency?

Sure it's a different story versus the same freezer stuffed full of frozen goodies... but I've always wondered if my changes have resulted in a power hog, or whether it's an overall efficient little machine... I've also wondered whether I should put the probe in water or just let it dangle... and those are thins I can monitor easily.

 

[HOP-HEAD]

This wouldn't be much of a correlation because the set temps are different. The delta between the conditioned space and the ambient temp is higher for the frozen food one.

No offense, but... no $hit "sherlock"...

 

[IffyG]

IIRC, when I was in the process of getting my keezer up and running last year, I found a thread where a member determined the cost of running his relatively new chest freezer converted to a keezer was something like 4 cents a day or so. Let's see what you come up with.

FWIW, I'm also going to be checking usage this week on my keezer and comparing it to next week with my newly fabricated collar.

 

[Catt22]

FYI, my 7.5 cu ft chest freezer with a 2 X 6 uninsulated collar, 110v AC muffin fan continuously, controller probe on the floor near the center with four full 5 gallon corny kegs consumes about 1.2 kwh/day. That would be about 14 cents/day or $4.33 per month based on a guess of about 12 cents per kwh.

 

[Catt22]

Obviously there are thousands of variables... but aren't you curious as to how an energy star freezer that draws very little operates after you remove the top, build a collar, and lower the temp setting while increasing the cycling frequency?

Sure it's a different story versus the same freezer stuffed full of frozen goodies... but I've always wondered if my changes have resulted in a power hog, or whether it's an overall efficient little machine... I've also wondered whether I should put the probe in water or just let it dangle... and those are thins I can monitor easily.

There are more than a few variables for sure, but the significant ones would probably number less than ten or so, not thousands. Yes, I am curious as to how much power the freezers consume and that is precisely why I am running the tests. IMO, they are quite efficient when used for their intended design, and the way we commonly use them even more so. I see no advantage to putting the probe in a container of water. The only thing that would do is delay the response time of the controller. IOW, increasing the lag time and causing temp overshoot/undershoot. So long as the container is not too large, this shouldn't affect the average temperature much, but you could accomplish the same thing by setting the differential higher (only if you have that capability, of course). So, that comes down to running longer, but less frequent cycles. This may extend the life of the compressor, but taken to extremes, it could lead to ice formation in the kegs or noticeable temperature swings in the served beer. I probably won't go to the trouble of testing all of these various configurations as it is very time consuming and requires patience to time the on off cycles. More patience than I am willing to commit. Then there is also the need to let the temperatures/cycles stabilize each time you change a variable. This can sometimes take a day or two. That's one of the things that makes it such a PIA, but hardly the only thing, I am rapidly discovering.

 

[passedpawn]

Stay tuned if you're as big of a nerd as I am...

Yea, I'm as big a nerd. I've had my outside chest freezer plugged into one for 2 weeks. Unfortunately, It hardly ever comes on because we are down in the 50's, and that's where I have my cf set (doing lagers now).

Kill-A-Watt. Lowes has them on sale for $25 right now. This is my second one (killed the first somehow).

 

[tomije87]

we are down in the 50's, and that's where I have my cf set (doing lagers now).

We're in the teens! Ambient temp in (detached) garage is ~35. I might as well open the lid!!!

Nevertheless, I'm more interested in the energy consumption with the temperature controller set rather than the comparison.

 

[HOP-HEAD]

11hrs, 46min... used .14 khr... or about $0.02.

Project that out for a month, and my 7.2 Frigidaire currently costs me about $1.21 a month at my current rate of $0.142/kwh....

 

[Catt22]

11hrs, 46min... used .14 khr... or about $0.02.

Project that out for a month, and my 7.2 Frigidaire currently costs me about $1.21 a month at my current rate of $0.142/kwh....

What was the ambient temperature during that 11 hrs, 46 minutes and what was the set point? Currently, if my freezer were in my garage the cost would be near zero if the set point were near the serving temp.

 

[Gritsak]

Out of curiosity, what's the target temp and range on your temp controller? Also, which controller?

 

[HOP-HEAD]

I use a Ranco set at 35°F with a 4 deg variation.

The Keezer is currently in my family room in the basement which sits at around 68°F.

For comparison purposes, I put the monitor on my huge, old clunker Magic Chef refrigerator in the kitchen over night. Used 1.45 Kwh in 10hrs, 52 minutes... or about $13.83/month... damn.

 

[Catt22]

I use a Ranco set at 35°F with a 4 deg variation.

The Keezer is currently in my family room in the basement which sits at around 68°F.

For comparison purposes, I put the monitor on my huge, old clunker Magic Chef refrigerator in the kitchen over night. Used 1.45 Kwh in 10hrs, 52 minutes... or about $13.83/month... damn.

I'd say your freezer is running very efficiently. A chest freezer will generally be less of an energy hog than a refrigerator as every time you open a refrigerator door, the cold air flows out like a river. This doesn't happen as much with a top opening chest freezer.

 

[HOP-HEAD]

I'd say your freezer is running very efficiently.

You mean Keezer? I haven't tested the freezer yet....

A chest freezer will generally be less of an energy hog than a refrigerator as every time you open a refrigerator door, the cold air flows out like a river. This doesn't happen as much with a top opening chest freezer.

The bad part is... this was plugged in last night before I went to bed, and unplugged this morning... the refrigerator might have been opened once... max. I bet if I test it over a longer period of time, it actually get's worse considering the repeated daytime opening and closing activity.

 

[Catt22]

You mean Keezer? I haven't tested the freezer yet....




The bad part is... this was plugged in last night before I went to bed, and unplugged this morning... the refrigerator might have been opened once... max. I bet if I test it over a longer period of time, it actually get's worse considering the repeated daytime opening and closing activity.

No, I meant freezer. IMO, the keezer term is much too gay. Never use it and I also never use the SWMBO term which seems to indicate a severe lack cojones.

I would prefer to use keggerator for a converted freezer with taps of some kind installed either in a collar or a tower. Lacking those alterations, it's just a chest freezer being operated at warmer temperatures. These are just my preferences, nothing more than that.

 

[passedpawn]

No, I meant freezer. IMO, the keezer term is much too gay. Never use it and I also never use the SWMBO term which seems to indicate a severe lack cojones.

I use both terms. But then I'm a gay eunuch.

Seriously, just words. Who cares.

 

[rjwhite41]

I refuse to use SWMBO for the exact same reason. I, however, have no problem with the word keezer. I have a kegerator though and don't have to worry about it.

 

[LarryC]

I'm going to try and resuscitate this thread (hopefully with out the word paranoia) to see if the OP ever finished his comparison of the freezer to the keezer. I have a 1.7 chest freezer that I'm trying to convince my wife should be turned into a keezer. Of course that means we buy a new freezer but knowing how much a month extra it will cost to have the keezer running is good ammo.

Any final results HOP-HEAD? (or any others who have done the analysis)