12V DC compressor refrigerators

[okmunky]

I'm looking into replacing my Dometic ammonia absorption refrigerator with a model that uses a Dan Floss 12 volt DC compressor to do the cooling. Many companies are now making them - Dometic, Nova Kool, Isotherm, Engle, etc. I’ve also found a company, JC Refrigeration, that makes a 12v compressor cooling unit that can be swapped out for the ammonia unit in your current refrigerator.

The advantage of compressor units is that they cool better and are not as sensitive to being off level. They use very little power and are ideal for boondockers.

Finding and comparing information on the various models is not easy. Google keeps finding me suppliers in foreign countries.

I am wondering now why RV manufacturers are not using this new technology. They aren’t that much more expensive than the ammonia filled beasts and a larger capacity fits into the cabinet space.

My dilemma now is deciding between new 9 cubic foot fridge or new cooling unit for my current 6 cubic foot Dometic. Is it worth $1100 for another 3 feet?

[mrgrayaz]

Here is the link the dometic I was talking about in your other thread.

https://www.dometic.com/en-us/us/pro...a-dmc-_-143818

when I talked to the Dometic guys at their booth in Hershey, PA - they really liked it. Biggest issue is (obviously) it does use 12V power and they recommended a decent battery bank and solar and were really positioning it to mid-high level 5th wheels and Motor homes that usually had such. Benefits are many.... you get solid controllable temps, not the wandering temps of the absorption. and of course you no longer need to get propane or worry about catching on fire. + fully warrantied in a RV unlike the residential, already catches on the doors, and no cabinet making to make it fit.

Anyway, I'm sold. if our absorption ever goes out, its straight what I'm going to

[aether_one]

RV manufacturers have not adopted it because unless you fork out the $$$$ to have enough solar to supply the fridge you are much more limited on cooling time when boondocking as compared to using a propane fridge, especially if you are camped in the shade of a forest.

[okmunky]

I have 2 golf cart batteries and 378 watts of solar, 100 watts of which can be placed up to 20’ from the rig if we need to. We are very low power users, especially at night. We use a propane ventless heater and I stay quiet after dark (no TV) so the fur kids will sleep. When I talked to Junior at JC refrigeration he said I'd have plenty of power.

Most likely I'll just replace the cooling unit with one from Junior and put extra insulation in the space that the ammonia unit takes up now.

Ok, this gets even more confusing for me. I finally got to the website

Home | JC Refrigeration

The compressor from JC Ref is not a DC compressor. It's an AC compressor and would require me to add a 1500 watt MSW inverter to run it. It says it "draws less than an amp" so should I consider that it will use less than 24 amp hours each day? How does that compare to the DC compressor units? This is the DC model spec sheet. I'm considering the RFU 9000 which is near the bottom on page 2.

http://www.novakool.com/support/docu...cLTCurrent.pdf

I appreciate all the help you guys are giving me on this decision.

[okmunky]

Originally Posted by mrgrayaz

Here is the link the dometic I was talking about in your other thread.

https://www.dometic.com/en-us/us/pro...a-dmc-_-143818

when I talked to the Dometic guys at their booth in Hershey, PA - they really liked it. Biggest issue is (obviously) it does use 12V power and they recommended a decent battery bank and solar and were really positioning it to mid-high level 5th wheels and Motor homes that usually had such. Benefits are many.... you get solid controllable temps, not the wandering temps of the absorption. and of course you no longer need to get propane or worry about catching on fire. + fully warrantied in a RV unlike the residential, already catches on the doors, and no cabinet making to make it fit.

Anyway, I'm sold. if our absorption ever goes out, its straight what I'm going to

Thanks for the link! Have you gotten a price on this model? I found the 9.1 cf Nova Kool for less than $1700 in Seattle - which is where I'm headed for the summer.

[Steve Kiemele]

Originally Posted by okmunky

I have 2 golf cart batteries and 378 watts of solar, 100 watts of which can be placed up to 20’ from the rig if we need to. We are very low power users, especially at night. We use a propane ventless heater and I stay quiet after dark (no TV) so the fur kids will sleep. When I talked to Junior at JC refrigeration he said I'd have plenty of power.



Most likely I'll just replace the cooling unit with one from Junior and put extra insulation in the space that the ammonia unit takes up now.



Ok, this gets even more confusing for me. I finally got to the website



Home | JC Refrigeration



The compressor from JC Ref is not a DC compressor. It's an AC compressor and would require me to add a 1500 watt MSW inverter to run it. It says it "draws less than an amp" so should I consider that it will use less than 24 amp hours each day? How does that compare to the DC compressor units? This is the DC model spec sheet. I'm considering the RFU 9000 which is near the bottom on page 2.



http://www.novakool.com/support/docu...cLTCurrent.pdf



I appreciate all the help you guys are giving me on this decision.

1 amp at 120 volts AC is 10 amps at 12 volts DC. More like 11 given the inefficiency of inverting. Over 24 hours, that could be 130 to 260 amps drawn from your batteries. My usable battery capacity from four 6 volt GCs is 200 amps. On a sunny day, my 580 watts of solar might supply 145 amps. An AC compressor is going to require a lot more solar or several hours of generator time

[okmunky]

Thanks Steve! That's what I'm afraid would happen.

[kayak70]

This is something I have been looking at hard because of issues with our Norcold 12VDC compressor refrigerator. Long thread in the WGO owners forum. They replaced the refrigerator after some other work, will get it tomorrow to see how the new refrigerator works. All the new Views will ship with this I understand.

I really like the Vitrifrigio 250 and the Isotherm Cruise 195. The NovaKool RF9000 is a perfect fit for my cutout but a single compressor. The other two are dual compressor units, one for freezer and one for refrigerator section and the published draw as rated is around 5amps DC. NovaKool might be great, has good reviews from owners and they report excellent customer support as well. All three have good compressor units according to reviews. Check the marine clubs for lots of reviews.

This site has a great comparison of units by cutout size to help decide what fits:

Refrigeration

click the box with red letters and you will get a chart of manufacturers by cu ft and by cutout size.

Good luck! The right unit and solar with good batteries and you should be good. I can't recommend the Norcold yet but will know soon how the replacement performs, fingers crossed I hope it is good!

Edit: Verify the operating temps in the freezer with each manufacturer. The nearer to 0*F the better. Some of the manufacturers just say "down to -6Celsius, not good. That's 21*F.

[Strongweld]

I love my Isotherm marine unit, it was worth the price

[Eez Moose]

Originally Posted by kayak70

Edit: Verify the operating temps in the freezer with each manufacturer. The nearer to 0*F the better. Some of the manufacturers just say "down to -6Celsius, not good. That's 21*F.

Just curious why one would want their frozen food to get this cold? The refrigerator in our home is set for -3C and the contents take forever to thaw out. Are you claiming better operation if the unit can get colder? TIA

[okmunky]

Zero degrees or below (-18*C) is where frozen food should remain for safety purposes. The refrigerator should be at 40* (4*C) or below according to USDA food safety experts.

https://www.fda.gov/ForConsumers/Con.../ucm093704.htm

Above those temps food starts to grow some bacteria or decline in quality. Not being able to keep my fridge temp below 40* consistently is one of the reasons I replaced the Dometic in my RV.

The new Nova Kool is sitting on the ground beside our coach connected to the batteries. I'm in the process of removing the Dometic now and hope to get the Nova Kool inside tomorrow. It is at 33* and 5* on a middle setting so I'm really pleased about that.

I'm a bit dissapointed in the interior features on the NK. The shelves, especially on the door are not as robust. I can adjust the height of the door shelves on the Dometic, not the NK. Warning! sexist comment - It looks like a man designed it. Beer cans would fit nicely in the doors, but not milk jugs or 2 liter soft drink bottles. The produce bins are not as deep, so for now I'm hanging on to the old ones that do fit. I use them for cheese and staples - deeper is better.

The latches and handles on the NK make it hard to open the doors. I'm calling NK tomorrow as the type of latches are specified on the shipping label, but I wasn’t consulted. I'm hoping there are better latches available.

[greenhorn1]

Read on another forum that JC refrigeration has a 12 volt compressor driven refer. Draws 5.5amps DC with a 30-80%run time over 24 hours

[jporietis]

I got the Nova cool 9 cubic ft model just over a year ago. We full time, use solar and have 4 t105 batteries. The fridge work's awesome.
The problem with a residential fridge is the savings in the fridge cost went towards an inverter and possibly more batteries, plus some carpentry work. With the Nova cool I got almost 3 more cubic feet of room and built an extra drawer for storage
The wiring from my never cold was good for new fridge.
These 12v compressor fridges have been used for years by the Marine industry and are not new, I can not understand why the RV industry is so slow to take advantage

[Kjmckay]

I pulled my fridge out couple months ago put in freon 11 cubic foot whirlpool with a thousand watt inverter and 6 batteries behind the driver and passenger seat in the basement once I Shore power the fridge to freezing in the freezer I can run it for a week with the solar off it was the best thing I did of course I need the batteries with the solar on I just wanted to see how long it would go good luck