12v Refrigerators

[Sasquatters]

We have been looking for 12v options since it seems like our current fridge is not going to work out for our solar setup. We would prefer something without a handle that sticks out like most of the Dometic models.

We have found several refrigerators that run on 12v and look nice, but we are unsure if they have a lock so that the door does not open while driving. Does anyone know of any 12v manufactures other than Dometic and Norcold? We are looking for something in white that is 59-61" tall, 24"wide, and no more than 26" deep.

[Tango]

It's a different approach, but I am going with a Whynter chest type freezer/fridge. They are very efficient 12 volt units but have to go under a counter...not upright.

[PNW_Steve]

I have looked at the SunFrost.

They look nice but cost $2000-$3200.

I am leaning towards buying a $350 refrigerator and spending an extra $1000 on solar gear & inverter to support it.

[Twigg]

Originally Posted by PNW_Steve

I have looked at the SunFrost.

They look nice but cost $2000-$3200.

I am leaning towards buying a $350 refrigerator and spending an extra $1000 on solar gear & inverter to support it.

That would be my choice too.

[Mgulley82]

We’re installing a traditional 120vac fridge and ensuring we have the batteries/solar/inverter to handle our needs

I’d rather invest the money in solar and off grid battery than in a propane/12 volt appliance

[PNW_Steve]

The cost of solar has come down far enough that expensive DC appliances are not nearly as attractive as they used to be.

in some circumstances it is now cheaper to add more solar capacity than to buy a more efficient appliance.

[joeblack5]

I use a Dometic 12 volt , (not gas) , compressor fridge. They have locks on the door. The other one is a 12 Volt Norcold, not gas, has lock on the door as well. These are small units and very efficient. They have the condensor on the back so that it is easy to insulate the top / bottom and sides better. Something what you cannot do with the average 120vac fridge since the condensor coils are often integrated in the walls. So you need to allow for air circulation. Paid 150 for the first one and $ 100 for the other on CL.
Dometic and Norcold use the same compressor from Danfoss.





Later J

[joeblack5]

Oh and by the way every Watt you waste away on the inside you will have to cool away as well. Efficiency pays.


later J

[Sasquatters]

Originally Posted by Tango

It's a different approach, but I am going with a Whynter chest type freezer/fridge. They are very efficient 12 volt units but have to go under a counter...not upright.

We do not have the space for that.

Originally Posted by PNW_Steve

I have looked at the SunFrost.

They look nice but cost $2000-$3200.

I am leaning towards buying a $350 refrigerator and spending an extra $1000 on solar gear & inverter to support it.

Well that was our plan but our friends got their fridge and solar setup first and it is killing their battery supply. 1.5 Hours after being unplugged and their batteries are drained to 50%. It is our understanding that the inverter multiplies everything by 10 to make the 12v batteries work on 120. With a 300w fridge that is a big problem. I don't want to have to pull a trailer of batteries just so we can have the fridge we currently have. Our solar setup is 1020w and we plan on having about 6 batteries.

[PNW_Steve]

Your solar array, charge controller and batteries need to be sized to fit your loads. Obviously your friends did not size their system to support the loads it was asked to support.

I have a 10.9CF refrigerator in my 5th wheel. I have no solar (yet) and I have 2 - GC2 6 volt/ 215AH batteries in series for 12v/215AH. I run a 1000 watt Xantrex PSW inverter.

I can run for 24 hours on battery before I need to plug in or start the generator.

In my bus I will have 1800 watts of solar, 4 - L16 6 volt/370AH batteries in series for 24v/370AH.

The cost of my refrigerator, solar panels and batteries are a bit more than a similarly sized Sunfrost would cost. The solar will be enough to provide all of my electrical needs except for air conditioning. In a pinch, it will run one of my air conditioners on low.

It is really up to you. I don't think that the 12 volt refrigerator is necessarily a bad idea. I think that saving around $2300 by buying a 120v fridge and spending $2300 on Solar is a better idea.

[PNW_Steve]

A couple more points:

The inverter will require the same watts in as it puts out. If you pull 300 watts from the inverter you will have to feed it 300 watts. Well almost true. Your inverter will not be 100% efficient so you have to feed it a tiny bit extra.

120 Volts x 2.5 Amps = 300 Watts

12 Volts x 25 Amps = 300 Watts

24 Volts x 12.5 Amps = 200 Watts

Batteries.... You mentioned "6 batteries". Are they AA or 8D? There are a lot of different batteries out there.

I am going to guess that you are looking at GC2's as they are one of the most popular. If so, you would wind up with a 36 Volt battery bank if connected in series. If you want 12 Volts you would connect them by paralleling 3 strings of 2 batteries in series . BAD idea. Trying to properly equalize 3 parallel strings can be very challenging.

I am rambling....

I would suggest taking a look at https://handybobsolar.wordpress.com/ and spend some time on https://www.solarpaneltalk.com/

It is WAY too easy to spend a lot of money on a system that does not perform up to your expectations. The best tool to avoid this is knowledge.

[Sasquatters]

That's what I am trying to avoid. We have 4 255w panels and I bought a Renogy 60Ampt MPPT controller that cannot handle over 800w so it's useless to us. We were looking at T105s, but decided on something a little bigger since the Amp hours was greater. I just don't want to keep buying stuff (like the controller) just to find out that it won't work as needed, or we didn't need as much power as we thought because we end up with a 12v refrigerator (which we don't want). I think we are going with the Trojan AEM series.

I am on several forums, but there's never really any clear answers and everyone just starts arguing that their setup is best and know what they are talking about more than the next guy.

[PNW_Steve]

Do you have the Energy Commander 60 Amp controller? if so, you can run up to 2800 watts. Depends on battery bank voltage.

Let's back up a bit now, what is your daily power requirement?

That is the first question that needs to be answered in the design process.

[JDOnTheGo]

Originally Posted by Sasquatters

That's what I am trying to avoid. We have 4 255w panels and I bought a Renogy 60Ampt MPPT controller that cannot handle over 800w so it's useless to us.

"Useless" may not be 100% accurate. Firstly, many controllers will clip off the excess power that they cannot handle. I'm not familiar with your model but something to look at. Secondly, if you flat mount your panels, you are likely to see only about 80% of rated output. So, 816 watts on the best of days.

Originally Posted by PNW_Steve

Let's back up a bit now, what is your daily power requirement?

Good call Steve!

[JDOnTheGo]

Oh... also... refrigerator power use is fairly difficult to measure and/or predict. Big variables (outside temperature, amount of time you like to stand there with the door open staring at the inside, etc.) have a significant impact on it's duty cycle. I mention this as just using the data on the label may not be indicative of actual power consumption.

I have a rather large residential refrigerator (Samsung RF24FSEDBSR - 23 cu. ft). Power consumption was measured over a 54 day period and averaged 64.4 Wh (5.12 Ah @ 12VDC). However; this was a single data point during not very challenging conditions so I don't consider it to be 'good' data but possibly interesting. This amount of power is easily supplied by the sun when, as Steve points out, the solar charging and power storage parts are properly designed/sized.

[PNW_Steve]

As JD stated there are significant variables that come into play.

I monitored my Frigidaire 10.9cf power consumption over a 3 month period of normal usage with ambient temperatures ranging from around 62F-78F. Daily consumption varied by as much as 20%.

I used my "highest day" when creating my energy budget.


Off topic: JD, have you measured power consumption of your LED lights while using the dimmer?

[Sasquatters]

This is the refrigerator we have.


This is the charge controller we have.


I don't have any numbers on me, but we will also have a 32" Samsung TV, a computer, router, led lights, cell phone chargers. Nothing that takes up a ton of electric.

Thanks for all the help.

[JDOnTheGo]

Originally Posted by PNW_Steve

Off topic: JD, have you measured power consumption of your LED lights while using the dimmer?

Just posted them over on my build thread.
http://www.skoolie.net/forums/f32/mi...tml#post270861

[JDOnTheGo]

Originally Posted by Sasquatters

This is the refrigerator we have.


This is the charge controller we have.


I don't have any numbers on me, but we will also have a 32" Samsung TV, a computer, router, led lights, cell phone chargers. Nothing that takes up a ton of electric.

Thanks for all the help.

I hate to say it, but you have work to do!!

An energy audit requires some time on your part. The items that you have in hand need to have their current draw measured. A tool like the Kill-A-Watt is invaluable. Plug your item into that you can see EXACTLY how much power it is using. Leave it plugged in for a day and you get a nice average. Next, you need to apply an anticipated time element to each item. How long are you going to use it each day? I can't explain it any better than I did here:
Energy Audit - Watt For? - JdFinley.com

If that doesn't make sense, there are plenty of other similar posts out there on the Internet.

Without data, all you can do is guess. Guessing usually results in the what your friends experienced - disappointment. I understand this stuff can be confusing and people may seem to be saying different things but data will eliminate all that. Data eliminates the need to guess.

I thought you previously said that your refrigerator was "300 watt", where are you getting that? Forget I asked, have you measured the current draw over the course of a day? If not, get a kill-a-watt, load it up with food, let it stabilize for a day or so and then start recording (for a couple of days).

[Sasquatters]

Ok, I will do that with everything.