Refrigerator for off-grid cabin

[Horsefly]

Please link to this. I couldn't find it. My understanding is that the compressor cooling unit completely replaces the absorption cooling unit, so you lose the propane/AC option.

I think I remember seeing a combo absorption / compressor fridge, but because the two methods share so little hardware, the usable space of the fridge was tiny, since the two separate cooling processes took up a ton of the space.

Edit to add: I have no idea where I saw such an animal.

 

[Pappion]

Please link to this. I couldn't find it. My understanding is that the compressor cooling unit completely replaces the absorption cooling unit, so you lose the propane/AC option.

the link is there in the blue, there are two options

 

[sunshine_eggo]

the link is there in the blue, there are two options

That's the thing. The two options are to replace with an AC/propane unit (a newer absorption cooling unit - no compressor) OR a compressor option.

I am not seeing an option where you can add a compressor and retain propane function.

 

[Rednecktek]

So what's the word on really small 12v fridges? My brother's pop-up has a tiny, like milk-crate-size-outside-dimensions absorption fridge which has ALMOST enough room for a 6-pack if you drink one or two first. Since I can't make the cabinet any larger, are there decent options for a straight 12v that would offer more usable space?

 

[12VoltInstalls]

the word on really small 12v fridges?

Expensive.
Reworking for a 120V cube fridge makes more sense to me- especially if it’s coils in back because you can add insulation to it.

 

[UpNorthMan]

I haven't kept up with this post, but I have a year old picture of a Home Depot fridge that kinda impressed me. I was there a few weeks ago and it appeared to be still available for the same price. Around 11 cubic in size. Sorry about the quality of the photo.

 

[Horsefly]

I haven't kept up with this post, but I have a year old picture of a Home Depot fridge that kinda impressed me. I was there a few weeks ago and it appeared to be still available for the same price. Around 11 cubic in size. Sorry about the quality of the photo.

What photo?

 

[12VoltInstalls]

What photo?

I’d like to see too
Last year HD had a non-frost-free 10.x cubic foot for $259 that advertised 80W but people reported 70-80W. Current similar units say 120W and 160W when I was there the other day. And as much as $399

 

[UpNorthMan]

Sorry for the delay, file didn't download. Might have been too large.

 

[12VoltInstalls]

been too large.

What is the running watts?

 

[Hedges]

Energy star label says 297 kWh/year which would be average of 34W running.
Actual motor start/run watts and defroster/icemaker watts (if it has those)? Don't know.

 

[12VoltInstalls]

Energy star label says 297 kWh/year which would be average of 34W running.
Actual motor start/run watts and defroster/icemaker watts (if it has those)? Don't know.

My too-small current fridge has the following energy label and is 80W running as measured with a Klein meter and the inverter readout. Sometimes for whatever reason it’s 60W
So it’s unclear about the 34W. I would expect more like 100W but I can’t see the sku on my phone to look and see what the advertised specs are.

 

[UpNorthMan]

When I make it that way I'll see if I can get more information. It's a 45 mile drive from home and 25 miles from work. One way of course.

 

[TXRural]

Replace the frig seals and stick with propane. Your going to be disappointed with the resulting battery life. My opinion and experience....

 

[Hedges]

Replace the frig seals and stick with propane. Your going to be disappointed with the resulting battery life. My opinion and experience....

Is your experience with a compressor-type refrigerator? Or running an absorption fridge with electric heating element?

 

[TXRural]

If you run anything over 30 watts all night long (off-grid), especially in cold weather, you'll seriously degrade even fairly large battery banks. I'm using 8, 6 volt 375AH L-16 batteries and found I had to stepp down to a 375watt (which pull 10watts just turned on running nothing) inverter so not to run my batteries below 50 volts by the next morning. That's about 78%. 49 volts would put me close to 60%, where electrolyte freezes. Even if you didn't get to freezing the electolyte your taking pretty serious longevity out of your batteries.

I set my system up so I can switch between 4 different inverters depending on light level, temperature, and power requirement.

 

[Don B. Cilly]

I said it before, but... repetita juvant I guess :·/

My 220V cheap fridge draws some 60W. It starts up approximately every 45 minutes and runs for some 15.
It starts off at about 80-90W, then quickly settles to some 50-60.
It's a normal, let's call it three-quarter-size house fridge, with a freezer compartment. I paid some €200 for it at the local house appliance shop - so they would deliver it free. It has an energy rating of, like D (for Dismal ;·)

My batteries (220 Ah, 24V, LFP), don't even notice it.
It does have a startup surge current. I run a circular saw off the (3kW, Chinese Cheapo) inverter. It actually jumps when you start it, imagine the surge current on that. My inverter smirks :·)

So honestly, I wonder just what you all are worried about.
-

 

[Horsefly]

I'm pretty sold on running off my 24V (230Ah 8S LFP) battery, rather than use the inverter. For the six months the fridge will be powered up, no one will be there about 50-60% of the time, so leaving the inverter on all that time will have lots of unnecessary tare loss from, as @TXRural has seen.

The fridge I linked to earlier says it only consumes 24Ah per 24hr period on average, which won't be a problem with my battery.

 

[TXRural]

Let us know how long the battery holds up. Please?

 

[Hedges]

If you run anything over 30 watts all night long (off-grid), especially in cold weather, you'll seriously degrade even fairly large battery banks.

Would be good to shed refrigerator loads at night. Let them make up for lost chilling after sun reaches PV panels in the morning.

I'm pretty sold on running off my 24V (230Ah 8S LFP) battery, rather than use the inverter. For the six months the fridge will be powered up, no one will be there about 50-60% of the time, so leaving the inverter on all that time will have lots of unnecessary tare loss from, as @TXRural has seen.

An inverter with standby would greatly reduce consumption whenever refrigerator isn't running.
Need to make sure defrost timer doesn't keep inverter on. Timer would then advance only when compressor (or heater) running. Unless you can ensure defrost cycle runs while sun is out, maybe unplug heater and defrost the old fashioned way (or have a switch on heater and use screwdriver to advance timer to defrost cycle when desired; it is sometimes under a plug on control panel.)


I'm in favor of drawing from battery as little as possible. I have a (relatively) small AGM back for my grid-backup system. It powers minimal loads for one night, mostly provides buffer and starting surge so AC coupled PV can directly feed big loads during the day.