Best truly efficient off grid fridge/freezer?

softdown

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

Photowhit

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

Photowhit

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 #.

softdown

https://forum.solar-electric.com/discussion/comment/395976#Comment_395976

Very similar unit and price. Oh well.

Dave Angelini

Build your own!

https://forum.solar-electric.com/discussion/comment/62546#Comment_62546

https://forum.solar-electric.com/discussion/comment/62546#Comment_62546

Or use a Stecca with German Engineering.

https://thesolarstore.com/steca-pf166-solar-refrigerator-or-freezer-12v-or-24v-dc-58cf-p-95.html

terracore

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:

https://www.amazon.com/gp/product/B079GWBQVZ/ref=as_li_ss_tl?ie=UTF8&psc=1&linkCode=ll1&tag=cd023-20&linkId=1b5f17aa714d80e96406768da7bd7bf9&language=en_US

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.

spacebass

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.

softdown

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:

https://www.amazon.com/gp/product/B079GWBQVZ/ref=as_li_ss_tl?ie=UTF8&psc=1&linkCode=ll1&tag=cd023-20&linkId=1b5f17aa714d80e96406768da7bd7bf9&language=en_US

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. 

softdown

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. 

BB.

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

706jim

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.

fratermus

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.  :-)

Marc Kurth

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

Dave Angelini

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.....

softdown

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. 

littleharbor2

No name BFFFF?  

softdown

littleharbor2 said:

No name BFFFF?  

It is likely covered by the stack of plywood leaning against a corner. I am constantly moving large stuff around it seems. 

softdown

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. 

BrianMoser

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.

softdown

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. 

Shubham5421

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.

softdown

Care to post a link to these units with "3 to 5" of insulation"? 

Dave Angelini

What is wrong with 49.8vdc ? Pretty typical. As long as you can fill it up daily, why do you care?

softdown

Dave Angelini said:

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.

petertearai

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  

Dave Angelini

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.

softdown

Well I was looking for efficient refrigerators instead of what my batteries can handle.

mike95490

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.

softdown

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.

Dave Angelini

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.

Marc Kurth

Dave Angelini said:

................... 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