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What refrigerator are you using?

Rmart30

Solar Enthusiast
Joined
Nov 16, 2023
Messages
249
Location
Alabama
What brand/model are you using off grid? Im curious about both small and larger sizes.

I know there are 12v specific models but they are pricey. Propane fridge is a no go for me.
This is for a cabin that it would only be ran for max 3 days at a time once monthly. I was looking at the 12v cooler fridges but they are more cost than one of the "dorm room" size fridges. I know a lot of those are not very efficient but, I pulled the trigger on a 3.5 cu ft model today. Manufacturer info says .41 kw a day. Going to put killawatt on it when it arrives and see what it says. I will give this one a try and see how it does. If it turns out to not be efficient enough I may look into something different.
 
I’m using a standard GE brand fridge for my full-time, off-grid home. These days, refrigerators are so much more energy efficient and solar panels so much cheaper that a modern refrigerator is more cost effective to run than the old propane powered refrigerators once popular when solar panels cost $5 to $10 dollars per watt.

You mentioned only staying 3 days per month at your off-grid place; that’s about how long a decent ice chest and a block of ice will last. If you prefer a refrigerator and your alternative energy system is on the small side, perhaps a very small chest freeze converted to run as a refrigerator would be an extra-efficient alternative for the couple days per month you’ll be there?

As I understand it, it’s a simple process to replace the freezer thermostat with a refrigerator one making your small chest freezer a refrigerator. The top-opening nature of the chest style unit means that you don’t dump all the cold air out every time you open the door making them consume less power. The extra insulation they have doesn’t hurt either.
 
I decided to go the full AC route and couldn't be happier. Some people try to go the DC route to minimize power consumption, but panels today are so dirt-cheap that going with a larger AC-based system works best for me.

With high-voltage residential panels selling for 40$ now (30V:250W), it's easy to put together a medium sized 24V system that could power your frig 24/7, 12 months out of the year. Just yesterday, I saw a seller within driving distance that was marketing new 540W panels for 100$ each. Two of those with four 6V golf-cart batteries (CostCo 440$ total), and a budget MPPT controller like a Epever Tracer 4210AN (110$). A somewhat more expensive Triron4215N would run you 150$. Add an inverter for another 300-600$. Maybe cheaper if you go the AiO route. That will make a LOT of power for <1200$. That would give you lights, TV/computer and a regular frig that you can leave on year-round.
 
I decided to go the full AC route and couldn't be happier. Some people try to go the DC route to minimize power consumption, but panels today are so dirt-cheap that going with a larger AC-based system works best for me.

With high-voltage residential panels selling for 40$ now (30V:250W), it's easy to put together a medium sized 24V system that could power your frig 24/7, 12 months out of the year. Just yesterday, I saw a seller within driving distance that was marketing new 540W panels for 100$ each. Two of those with four 6V golf-cart batteries (CostCo 440$ total), and a budget MPPT controller like a Epever Tracer 4210AN (110$). A somewhat more expensive Triron4215N would run you 150$. Add an inverter for another 300-600$. Maybe cheaper if you go the AiO route. That will make a LOT of power for <1200$. That would give you lights, TV/computer and a regular frig that you can leave on year-round.
We are looking at an all new system & new 600 W panels, 50 V VOC are retailing at about €110 each delivered. A mate has a 12 V fridge freezer in his VW camper & it's amazing, frozen food in the icebox, very low draw but cost €1200 !
 
What brand/model are you using off grid? Im curious about both small and larger sizes.

I know there are 12v specific models but they are pricey. Propane fridge is a no go for me.
This is for a cabin that it would only be ran for max 3 days at a time once monthly. I was looking at the 12v cooler fridges but they are more cost than one of the "dorm room" size fridges. I know a lot of those are not very efficient but, I pulled the trigger on a 3.5 cu ft model today. Manufacturer info says .41 kw a day. Going to put killawatt on it when it arrives and see what it says. I will give this one a try and see how it does. If it turns out to not be efficient enough I may look into something different.
I have the midea 7 cf convertible chest unit which was about $169 out of Costco, it takes 3-4 days to use a kw
 
You mentioned only staying 3 days per month at your off-grid place; that’s about how long a decent ice chest and a block of ice will last.
Im just trying to have to carry as few items as i can each trip and have everything there in case I get chance to run down there real quick after work or something. Easier to turn on fridge for a overnight than to stop and grab ice(with no cooler) and drive the 25 minutes from the store in the summer to get it into cooler.
I drive a compact car most of the time for the gas mileage. Ive kidded with the wife about buying a old UPS truck with shelving and loading it down with all my stuff and just driving it around .. lol
 
4Yrs ago I chose to go with a 4.3cuft 120v dorm fridge for our weekend off grid cabin. I'm glad I did as we are useing the cabin more and staying longer I would like to upgrade a few things. A bigger fridge and a 48v system.

I would never build a 12v system ever again and I would never limit my self by useing 12v appliances. Generaly by the time you buy more expensive "offgrid" and non 120v appliances you can build a bigger solar setup.

For you and this being a weekend cabin having a huge battery is key as it has 5 days to recharge.
 
I've done the math several times and each time found that the larger the fridge less energy per cubic ft it uses. EG: Dorm fridges are terrible

These fridge discussions seem to lose site that the difference between the worst and the best fridges is around 200 watts, more or less, of solar panels.

Also the most "efficient" fridges really aren't that efficient, rather they don't have a self defrost function which, depending on your climate, can turn your fridge into a mold factory.

You do you, of course.
 
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Ive been looking at this
Which can be used as a fridge by just setting the thermostat. Its claimed that this unit can maintain 0c for up to 135 hours without power. Im not sure if this brand is avalable where you are ?

That's kind of like the windshield washer fluid I saw that was guaranteed not to freeze above 32F/0C.

Anything with thermal mass and insulation will stay below some temperature for some period of time.
The magic with phase transition materials like water/ice is that after it has warmed up to 0C, it sits at that temperature until all the ice has turned to water before warming above 0C.

What they mean is that if you fill it with some amount of ice and keep it closed, the ice will last 5 days.


At my place I use half a dozen old refrigerators and freezers, some rather power hungry, some newer and more efficient.
Two I have recharged with refrigerant. Two of the refrigerator/freezers I've converted to all freezer.
I've got two chest freezers, one I bought and one I picked up at the curb (has bad thermostat, bypassing that it got down to -32F. Just needs a new thermostat.)

I have grid backup, not full offgrid, so I can get away with the inefficient equipment. As I lose net metering I might transition toward more efficient models, use the old ones while doing defrost or for other properties.
 
What they mean is that if you fill it with some amount of ice and keep it closed, the ice will last 5 days.
That’s a fair point, I thought it was a big claim to make. This unit is ok for unheated garages & outbuildings so it’s interesting for us. The energy rating says about 0.5 KWh / 24 hours & being off grid that’s important.
 
That’s a fair point, I thought it was a big claim to make. This unit is ok for unheated garages & outbuildings so it’s interesting for us. The energy rating says about 0.5 KWh / 24 hours & being off grid that’s important.
That's about the same useage my $200 4.5cuft mini fridge uses with separate top freezer. Minus inverter losses.
 
I've done the math several times and each time found that the larger the fridge less energy per cubic ft it uses.

These fridge discussions seem to lose site that difference between the worst and the best fridges is around 200 watts more of less of solar panels.

Also the most "efficient" fridges really aren't that efficient, rather they don't have a self defrost function which, depending on your climate, can turn your fridge into a mold factory.
We have a basic top freezer 18 cu ft household fridge from Lowes. One of the cheapest units they sell and is exponentially nicer and more convenient than the 12v/gas fridge in our RV. It barely uses more power than the old dorm style fridge we were briefly using that was 1/10th the size. We keep the power off when not there, so there is an additional amount it uses for the initial cool off. All in all it doesn't use that much and it's easy enough to throw a little more power at the system if you even need to.

100% agree with Oz, it's not worth pissing around with tiny stuff to save a tiny amount when you can produce energy so easily with the new equipment.
 

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