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Mr RoC
Member
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# Posted: 22 Jul 2018 05:44pm - Edited by: Mr RoC
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My cousin was inquiring about a compact fridge for his small solar set-up and though I'd share my data:
Cabin inside temperature 25*c
Danby 4.4 cu ft compact fridge with interior LED lights and auto defrost and is estimated at 268 kWh yearly.
Fridge temperature set at one dot below highest setting.
Fridge location - tucked in a corner with the back of the fridge about 1 foot away from the wall and normal access to food and cold drinks throughout the day.
 
Compressor not running:
  
Fridge door open and fridge LED light on:
Compressor initial start up:
Compressor running:
 
After 24 hrs fridge ran for 7 hrs, 39 min:
Highest and lowest wattage usage:
 
Cheers.
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Borrego
Member
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# Posted: 22 Jul 2018 07:34pm
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Thanks, interesting..I have a Danby 10 cf, that draws 296 kwh/yr.
Wonder how close it is.....?
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Nate R
Member
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# Posted: 22 Jul 2018 07:36pm
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We need more of this around here!
Thanks for doing that. What are you using for the data? Not a Kill-A-Watt but...what?
Do we know if it ran through a defrost cycle for sure?
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Mr RoC
Member
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# Posted: 22 Jul 2018 08:11pm
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MegaPower (TM) Plug Power Meter Monitor off of Amazon
Could'nt tell you when the defrost cycled.
Cheers
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Nate R
Member
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# Posted: 22 Jul 2018 09:30pm
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Just asking about the defrost, as your .434 KWH/day is 158/yr. So I'm wondering if it's actually that much lower than the "estimate" from the Energy Guide, or if it just didn't go through a defrost cycle yet, and we're seeing lower numbers than we otherwise would.
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Wilbour
Member
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# Posted: 23 Jul 2018 12:00pm - Edited by: Wilbour
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I'm skeptical about the peak wattage reading. The fact that the peak usage is very short makes me wonder if the meter is able to capture the value accurately.
I mean it's probably close but I have a much smaller fridge with a higher peak value.
Now yours may be a better brand so that could make all the difference. What's obvious is how inefficient my smaller fridge is watts/c.f..
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Brian Ray
Member
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# Posted: 23 Jul 2018 12:53pm - Edited by: Brian Ray
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I chose this mini fridge due to its advertised power consumption and it happened to be on sale at store near me https://mcappliance.com/brands/magic-chef/2-6-cu-ft-mini-refrigerator-665679004508.ht ml
I did a little testing before bringing it to the cabin. I used an oscilloscope to monitor electrical current and interior temperature. It’s interesting, if nothing else.
The capture is about 5.5 hours long. The blue trace is an amp probe on the power cord, Green is interior temperature.
Temperature starts at about 77° F, ends up around 36°. The compressor draws about 624 milliamps when running.
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Wilbour
Member
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# Posted: 23 Jul 2018 07:16pm
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I love this stuff! 
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creeky
Member
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# Posted: 24 Jul 2018 10:24am
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Nice work Brian.
Also shows the benefit of a better quality compressor. smile.
And syncs with my less elegantly described 500w/day use with a MagicChef 10 cu.ft.
I used an older EM100 energy meter. 8-10 years old now. Doesn't show peak etc. But I ran it for a week. Divided by 7 to get the daily load. This way you are seeing defrost cycles. It was also fall when I did this. Room temp around 22C.
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Brian Ray
Member
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# Posted: 24 Jul 2018 01:22pm
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Thanks Creeky,
I believe your method is more practical, simple setup and most of the math is done for you.
As Wilbour mentioned, it’s possible these types of monitoring devices won’t sample fast enough to accurately measure the compressor startup current. I measured the duration of the startup current in my capture, it’s about 250 milliseconds. So as long as your device samples at least 4 times/second or 4Hz, it should catch it. Even though the EM100 doesn’t display peak values, it may be calculating the peak values into the total consumption.
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Wilbour
Member
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# Posted: 24 Jul 2018 01:56pm
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Brian,
Thanks to you I ordered the same power meter. Found it on Amazon.ca for less than $20.
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Brian Ray
Member
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# Posted: 24 Jul 2018 02:08pm
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Quoting: Wilbour Found it on Amazon.ca for less than $20.
Sounds like a good deal, I had to pay a bit more than that for my scope 
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creeky
Member
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# Posted: 25 Jul 2018 10:46pm
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Ahhhh. Now I want one too.
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Bancroft bound
Member
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# Posted: 28 Jul 2018 10:46am
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Great thread!
This is exactly my experience with this same model.
Those pictures are worth a thousand words.
BTW, it is all fridge and I don't recall a auto defrost cycle. I think you have to do it manually, ....... turn it off till frost ,if any, is gone!
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Nate R
Member
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# Posted: 28 Jul 2018 01:07pm
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Good point! With no freezer there probably isn't a defrost timer at all!
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Wilbour
Member
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# Posted: 28 Jul 2018 03:13pm
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Quoting: creeky Ahhhh. Now I want one too.
Go for it. Mine was dropped off by drone yesterday 
Nah, just kidding, Canada Post left it behind.
Got to order a book for your misses so you can get free shipping.....Hope mine likes "The Joy of Solar" I read the chapter called "It's ok to play with it" Shocking! 
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creeky
Member
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# Posted: 30 Jul 2018 09:33am
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Well. Maybe you'll lend me yours when you're done with it.
um. sanitized of course.
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Wilbour
Member
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# Posted: 30 Jul 2018 12:35pm
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Quoting: creeky Maybe you'll lend me yours when you're done with it
Book or meter?
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creeky
Member
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# Posted: 31 Jul 2018 06:19pm
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both? but I would like to check the em100 for accuracy. I've come to realize, over time, that cheap meters are often not that accurate.
Plus all the cool features. Max draw. wow. I'd kinda like to know what my lowest draw is. System idle as it were. Then there's ...
Uh oh. I 've got enough to do. Cancel my order.
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Mr RoC
Member
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# Posted: 21 Oct 2018 05:38pm
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Just an update on the power consumption during the fall season. Took a reading over a 24 hour period this weekend with cooler fall temperature and no humidity.
Inside cabin temperature was 21*C with no humidity and a big reduction in the fridge's power consumption. From Saturday 10am to Sunday 10am with regular access to food and drinks the fridge ran for a total of 4hr 47min.
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