Best truly efficient off grid fridge/freezer?

softdownsoftdown Solar Expert Posts: 3,309 ✭✭✭✭

Our fridge is likely to be our largest consumer of power when off grid. So I searched for something "ground breaking" and found an "item of interest." The walls are 3"-5" thick. Runs on 12 or 24 volt DC. Chest configuration so the cold air doesn't fall out every time the door is opened. Only one review to date. States very low energy usage but gave it four stars. Perhaps they were a tad disappointed in the interior space? Insulation occupies a large percentage of the unit. Costs $1300. Weighs 154 pounds. Offers 8 1/2 cu. ft. of storage space.

I'd guess this a good value for a certain niche. Headquarted in Germany and claiming a year 2000 start up date. If I was our host, I'd take a closer look at offering this unit. Their American headquarters are in Tucson, AZ. https://www.phocos.com/na/blog/portfolio/fr240/

https://www.amazon.com/Phocos-FR240MP-DC-Refrigerator-Freezer/dp/B017BXQY2G/ref=sr_1_5?keywords=inverter+refrigerator&qid=1551979607&rnid=2941120011&s=appliances&sr=1-5

First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
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Comments

  • PhotowhitPhotowhit Solar Expert Posts: 5,242 ✭✭✭✭✭

    They currently sell a highly regarded(in solar circles) Sundanzer 8 cu Ft chest fridge/freezer(fridge or freezer dependent on the thermostat)If you look it up on Amazon, you will find 3 bad reviews I believe 2 out of the 3 are from people using them in a commercial environment. They have double seals and trying to open the doors rapidly stresses both the seals and the hinges, the things people complain about.

    https://www.solar-electric.com/sundanzer-dcr225-battery-powered-refrigerator.html

    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, 660 ah 24v ForkLift battery. Off grid for @16 of last 17 years. Assorted other systems, and to many panels in the closet to not do more...lol
  • PhotowhitPhotowhit Solar Expert Posts: 5,242 ✭✭✭✭✭

    Where are you located? I think Florida, I know where there is one of these in Missouri from someone who used it at their hunting cabin. Reasonably priced. I think I still have the Phone #.

    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, 660 ah 24v ForkLift battery. Off grid for @16 of last 17 years. Assorted other systems, and to many panels in the closet to not do more...lol
  • softdownsoftdown Solar Expert Posts: 3,309 ✭✭✭✭
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • terracoreterracore Registered Users Posts: 10 ✭✭
    edited May 2019 #6
    A regular chest freezer (not a "frostless" model) converted into a refrigerator uses about 10% the power of an equivalent side-by-side upright fridge.  Modern "frostless" refrigerators use half their energy on the "frostless" feature and actually run a ~600 watt heater during the defrost cycles, which subsequently warm the cooled areas and require more refrigeration energy to keep the food cold. 

    So you can skip the expensive DC route and do what most off-griders do and buy a ~$200.00 chest freezer from Home Depot or Lowes or wherever and convert it into a refrigerator with a $30.00 product like this in less than 3 minutes:


    To answer the second part of your question about an "off grid freezer", we use a regular chest freezer from Home Depot.  It pulls about 89 watts and we set it at max cold which takes it down to about -8F.  It only runs during the day when the sun is out (we use a regular appliance timer).  It's never been warmer than about 12F when it kicks on again in the morning which is still 20 degrees below freezing.  As long as you keep it full it only has to run a few hours per day to keep everything frozen.  Occasionally if we kill a pig or something and dump a bunch of warm stuff into it, obviously we have to extend the run time if we're putting into the freezer in the evening etc.

    You can even get clever and put a jug of water to freeze into the chest freezer in the morning, and then put it into the converted "refrigerator chest freezer" in the evening, and store the sun's power thermally in the form of ice rather than trying to put the power into more expensive batteries.  The frozen jug will help keep the refrigerator cold without using electricity.  Then move the jug to the freezer in the morning when the sun is out, rinse and repeat, etc.

  • spacebassspacebass Registered Users Posts: 74 ✭✭
    edited October 2019 #7
    Must buy an Inverter fridge freezer I live in Thailand I have a 14.2 cu ft LG inverter fridge freezer I have measured it twice over 24 hours at  1.1 and 1.2 kwh. The defrost cycle wattage is 161 watts.
  • softdownsoftdown Solar Expert Posts: 3,309 ✭✭✭✭
    terracore said:
    A regular chest freezer (not a "frostless" model) converted into a refrigerator uses about 10% the power of an equivalent side-by-side upright fridge.  Modern "frostless" refrigerators use half their energy on the "frostless" feature and actually run a ~600 watt heater during the defrost cycles, which subsequently warm the cooled areas and require more refrigeration energy to keep the food cold. 

    So you can skip the expensive DC route and do what most off-griders do and buy a ~$200.00 chest freezer from Home Depot or Lowes or wherever and convert it into a refrigerator with a $30.00 product like this in less than 3 minutes:


    To answer the second part of your question about an "off grid freezer", we use a regular chest freezer from Home Depot.  It pulls about 89 watts and we set it at max cold which takes it down to about -8F.  It only runs during the day when the sun is out (we use a regular appliance timer).  It's never been warmer than about 12F when it kicks on again in the morning which is still 20 degrees below freezing.  As long as you keep it full it only has to run a few hours per day to keep everything frozen.  Occasionally if we kill a pig or something and dump a bunch of warm stuff into it, obviously we have to extend the run time if we're putting into the freezer in the evening etc.

    You can even get clever and put a jug of water to freeze into the chest freezer in the morning, and then put it into the converted "refrigerator chest freezer" in the evening, and store the sun's power thermally in the form of ice rather than trying to put the power into more expensive batteries.  The frozen jug will help keep the refrigerator cold without using electricity.  Then move the jug to the freezer in the morning when the sun is out, rinse and repeat, etc.

    I would absolutely do that if strapped for battery power. Batteries are good and I am still quite tempted. Put the Kill-a-watt meter on my large chest freezer - it does very, very good compared to the fridge. I like to give it a week or so - then I will post results if I remember. 

    Seems you would get a lot of frost on your food fluctuating from -8F to 8F on a daily basis. 
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • softdownsoftdown Solar Expert Posts: 3,309 ✭✭✭✭
    Hopefully the defrost cycle would never turn on when the freezer is being run over 32F. 

    It wouldn't surprise me if more high end fridge/freezers had more active defrost cycles and consumed more energy as a result. People that buy high end fridges are likely not too worried about defrost cycle energy usage - they want pretty food. 
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • BB.BB. Super Moderators, Administrators Posts: 30,712 admin
    Neil, a former moderator here did a test on a fridge/freezer with a kWH meter--And after disabling the defrost cycle, found that after ~24 hours, the evaporator started to freeze up and average daily energy consumption started to increase.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • 706jim706jim Solar Expert Posts: 344 ✭✭✭
    Back when solar panels cost more than $5/watt, the power consumption of an electric fridge made them impractical for off grid living. Now with panels so much more affordable, I think any decent modern fridge should run just fine off of solar unless you only have 300 watts of panels. Mine has that defrost cycle and power consumption with a 2400 watt system has not been a problem.
    Island cottage solar system with 2400 watts of panels, 1kw facing southeast 1kw facing southwest 400watt ancient Arco's facing south.Trace DR1524 MSW inverter, Outback Flexmax 80 MPPT charge controller 8 Trojan L16's. Insignia 11.5 cubic foot electric fridge. My 27th year.
  • fratermusfratermus Registered Users Posts: 42 ✭✭
    Vandwellers commonly use 200w of panel to power a compressor fridge and incidentals.  I run a tiny 15L Alpicool that pulls 12A every 24hrs. I admit this wouldn't be a great fit for folks traveling with families.  :-)
    2017 Promaster 159" DIY camper
    570W mono / 220AH GC
  • Marc KurthMarc Kurth Solar Expert Posts: 791 ✭✭✭✭
    edited October 2019 #13
    BB. said:
    Neil, a former moderator here did a test on a fridge/freezer with a kWH meter--And after disabling the defrost cycle, found that after ~24 hours, the evaporator started to freeze up and average daily energy consumption started to increase.

    -Bill

    Good input, Bill.
    Marc
    I always have more questions than answers. That's the nature of life.
  • Dave AngeliniDave Angelini Solar Expert Posts: 5,272 ✭✭✭✭✭
    Probably saved someone from ruining a load of food.

    The best refrigerator for offgrid is a power system designed to run it.
    This is pretty basic, I would think.....
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • softdownsoftdown Solar Expert Posts: 3,309 ✭✭✭✭
    My great big chest freezer used just 2.6 kWH in six days. Keeping the food at 0F. It is also frost free.

    Sorry - cant find a brand name on it. 
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • littleharbor2littleharbor2 Solar Expert Posts: 1,525 ✭✭✭✭
    No name BFFFF?  :o

    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric, 700 ah @24 volt AGM battery bank. Plenty of Baja Sea of Cortez sunshine.

  • softdownsoftdown Solar Expert Posts: 3,309 ✭✭✭✭
    No name BFFFF?  :o
    It is likely covered by the stack of plywood leaning against a corner. I am constantly moving large stuff around it seems. 
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • softdownsoftdown Solar Expert Posts: 3,309 ✭✭✭✭
    Amazon and Costco are both peddling GE and Frigidaire freezers. Those names are not what they used to be. I've lost a freezer full of food and don't want that again. 

    Remember when fridges and freezers used to last for 30-40 years? Sigh. 

    I've got an upright commercial freezer that is likely fine. I wonder what would happen if I turned that into a fridge. Commercial units usually have strong compressors - bad for energy usage. But freezers seem to offer ~twice the insulation. 

    Wish I'd have bought that used lab fridge. Think the sides were 3" thick and rated to get super, super cold. Maybe -100F? The plug was "odd" so I thought it was 220 volt. Sigh. 
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • BrianMoserBrianMoser Registered Users Posts: 3
    My feeling is to use a standard Energy Star rated fridge. They consume "about" 1Kwh of power a day, and my 2, 20CF fridges have plenty of room. The "solar" fridges are often just 7-10CF.

    The drawback is, they expect Hover Dam on the end of the cord, and have a hefty starting surge, which means most 300 or 400 w inverters do not have enough capacity to start the fridge. Most of the 1,000w inverters are able to start the fridge.
    Experience is what you get when you didn't get what you want
  • softdownsoftdown Solar Expert Posts: 3,309 ✭✭✭✭
    My 2008 17 c.f. Energy Star fridge uses about 1.4 kWH/day. Not bad enough to replace I guess. I'm on a kWH hunt now that system voltage drops down to 49.8 at times. 

    Did install a bunch, 8, of ultrasonic pest repellers that consume about 6 watts/each. Rodents search for warmer areas as the weather gets colder. I'd rather not house them. Might disconnect most pest repellers for a couple months - starting in a month or so. 
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • Shubham5421Shubham5421 Registered Users Posts: 2
    Well, honestly.. all of us are concerned of the appliances that we purchase as because these are more like a huge investment that we make. It is quite obvious that it needs to be perfectly up and running and a long lasting appliance.

    If you are going to take my opinion, I would say Efficient refrigerators for living off the grid using solar panels for your house should be the most efficient in almost every aspect, lowest energy consumption and delivering the best performance. Super-efficient electric fridge and refrigerators are generally designed with 3 to 5 inches of insulation use only one third the energy of most standard units.
  • softdownsoftdown Solar Expert Posts: 3,309 ✭✭✭✭
    Care to post a link to these units with "3 to 5" of insulation"? 
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • Dave AngeliniDave Angelini Solar Expert Posts: 5,272 ✭✭✭✭✭
    What is wrong with 49.8vdc ? Pretty typical. As long as you can fill it up daily, why do you care?
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • softdownsoftdown Solar Expert Posts: 3,309 ✭✭✭✭
    What is wrong with 49.8vdc ? Pretty typical. As long as you can fill it up daily, why do you care?


    I can't figure this one out.
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • petertearaipetertearai Solar Expert Posts: 442 ✭✭✭✭
    Think Dave may be alluding to designing a system that will run the loads you have . Thickness of insulation possibly irrelevant . Energy star label that is correct. And verification in real life even better  
    2225 wattts pv . Outback 2kw  fxr pure sine inverter . fm80 charge controller . Mate 3. victron battery monitor . 24 volts  in 2 volt Shoto lead carbon extreme batterys. off grid  holiday home 
  • Dave AngeliniDave Angelini Solar Expert Posts: 5,272 ✭✭✭✭✭
    Really ? You don't know what 49.8vdc is telling you?  Really?  Below is one of my battery systems going thru about 12 hours. The normal heat pump and breakfast loads  (about 1500 watts) just after 7 am.  It dips to just above 48vdc but under a medium load. Probably never got discharged more than 30 or 40 percent from full. Then 30 minutes later it is going back to full supporting the loads with solar.

    Another reason here why it is so valuable to see a power system graphically and easily understand what it is doing.




    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • softdownsoftdown Solar Expert Posts: 3,309 ✭✭✭✭
    Well I was looking for efficient refrigerators instead of what my batteries can handle.
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • mike95490mike95490 Solar Expert Posts: 8,862 ✭✭✭✭✭
    Shop the yellow efficiency tags on the energy star fridges.  Models change 2x a year, see what consumer reports lists for a reliable fridge.   But the Energy Star models are the ones to look for.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • softdownsoftdown Solar Expert Posts: 3,309 ✭✭✭✭
    edited April 13 #29
    I suspect Energy Star is virtually mandated for full size systems. Couple challenges:
    1) Manufacturers can cheat and lie on the tests.
    2) I'm leary of quickly evaluating reliability on something that should last at least a decade. How can we really evaluate a fridge after a few weeks? People either rate their buys pretty quickly - or never get around to it.

    Changing the subject a bit here - the Costco business center recently started carrying a Daewoo 18.2 cu. ft. inverter fridge/freezer made in Mexico for $400. It does quite well in energy usage considering it has defrost built in. Here are the numbers: 399 kWh/year. Though 399 is a suspicious number.

    I may have bought it but my income just went to 0.0.
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • Dave AngeliniDave Angelini Solar Expert Posts: 5,272 ✭✭✭✭✭
    It is pretty basic, but to make this project as long as possible you definitely do not want to measure the refrigerator that you want or need.

    For others it is just a matter of knowing your battery capacity. A typical 400ah 48 system can support most all refrigerators that you can buy these days. Best to keep them below 25 cu ft. for offgrid but I have folks that do more. The key is being able to recharge reasonably quickly and early in the day.
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • Marc KurthMarc Kurth Solar Expert Posts: 791 ✭✭✭✭

    ................... The key is being able to recharge reasonably quickly and early in the day.

    Can't help myself. I just have to repeat this wisdom!
    Marc
    I always have more questions than answers. That's the nature of life.
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