12 volt refrigerator

While checking out all the goodies at the Tampa RV show today, we saw a few  trailers and 5 wheels with 12 volt refrigerators. They were 10 cubic foot models, bigger than the usual unit in trailers that sized but smaller than a residential unit. I am not familiar with 12 volt fridges but it seems they operate like anything else on the units 12 volt system, through the converter when on shore power and battery when unhooked. I asked one of the sales reps if they were absorption units and he said they were not, and that they had a small compressor. Do any of the members here have any experience with a strictly 12 volt fridge?  If so, what has been your experience, good bad or otherwise?

I do not know what the proper name is but there is a group of Compressors. one of them is made by a company called Danfoss and that's the name I use for the group. Very efficient... Next to me is a chest freezer (ENgle calls the compressor a "Sling" but it's of that class) this is a couple cubic feet  (I think it holds something like 44 12 oz cans) but it draws a great whomping 36 watts running (By comparison a pair of 1141 lights (common ceiling fixture) is 38 watts)

Both Dometic and Norcold made full size upright RV Fridge/freezers using this technology as well as chest type.

Patnsuzanne said:

we saw a few  trailers and 5 wheels with 12 volt refrigerators. They were 10 cubic foot models,  I asked one of the sales reps if they were absorption units and he said they were not, and that they had a small compressor. Do any of the members here have any experience with a strictly 12 volt fridge?  If so, what has been your experience, good bad or otherwise?

Click to expand...

I believe this member that has the exact 10CF model you saw (made by Unique), he swapped it in for an absorption. He's commented that it takes about 50AH/day to run.

I also have an Engel freezer, the 3.25CF model. Like John From Detroit I purchased it for the low power draw.

12v compressor-driven fridges are not unusual in the marine industry, though most are smaller sizes.  They are finally beginning to get more popular for RVs as well.

Gary RV_Wizard said:

12v compressor-driven fridges are not unusual in the marine industry

Click to expand...

Indeed, as I understand it Engle's primary business for years was long distance sailboats

I looked at the Furrion 10 cube. The company website offered an energy usage rating for a full year. Not a word about on demand compressor consumption. Flag went up immediately. I could not find any other energy rating for the fridge. It doesn't come at a bargain price either.

My impression is that it may be beneficial for some RVers but not so with others. I also am skeptical of an energy specification that doesn't fit the function. Buyer beware. Here is a link to it.

https://furrion.com/products/10-cu-ft-dc-refrigerator-stainless-steel

We have this Unique 13 cu ft refrigerator.  https://uniqueappliances.com/product/unique-9-3-cu-ft-solar-powered-dc-chest-freezer/  Installed it last March and so far it has held up quite well.  It's a no frills basic box.  Pricey compared to a residential with no ice maker or through the door water dispenser.  But it does the job and doesn't have the fire risk of a propane refrigerator.  Since installing the refrigerator we have traveled about 6,000 miles and our preferred style of camping includes public campgrounds and boon docking so a fair amount of unpaved travel. 

Battery consumption is 50 - 75 Ah's a day when dry camping.  We keep the RV at the house and it's always plugged into a 120V receptacle.  As you know, the RV converter maintains the 12V power.  The freezer temps usually 0 - 10?.  The refrigerator 35 - 38?. 

That is fairly reasonable. The fridge draws a little over 5amps when the compressor runs which is pretty good. Quite a bit better than an electric absorption. I would be a little concerned that the fridge is dedicated  to battery power when not plugged in but with careful planning and good charging habits it would seem to be useful. Battery type becomes important and it would be best to use a lithium battery system. A solar charge would also help. A lead acid battery system would fall victim to the constant low charge condition depending what you are doing of course.

I have been looking at these for my 5th wheel. They are available at Home Depot. When you look at the total price for a residential ref install with the inverter, wiring and transfer switch these 12V ref are a little cheaper and are made to be mobile and bounced around. The power consumption is also less than a residential ref install.

Henry J Fate said:

I looked at the Furrion 10 cube. The company website offered an energy usage rating for a full year. Not a word about on demand compressor consumption. Flag went up immediately. I could not find any other energy rating for the fridge. It doesn't come at a bargain price either.

My impression is that it may be beneficial for some RVers but not so with others. I also am skeptical of an energy specification that doesn't fit the function. Buyer beware. Here is a link to it.

https://furrion.com/products/10-cu-ft-dc-refrigerator-stainless-steel

Click to expand...

it's thirsty.. they quote 463 kW/hr for the year..  divide that by 365 for an average daily use then we get 1268 W/hrs.

almost double the unique appliances unit.. not the preferred thing, especially not for boondocking..

That is quite thirsty. My other concern would be recovery time or the actual heat removal when the compressor is running. It could be that the higher wattage indicates more heat removal but since they want to hide all those specifications, it makes me think that somethings not right and it's probably not right. Things may be all fine and dandy for awhile after these new purchases leave the showroom but I suspect premature battery replacement and low voltage conditions will take its toll. It could be set up well and work well but it looks like they are just throwing these things in and telling everyone how wonderful it is. I do like the 12 volt feature though. How about a fridge with two cooling systems? An absorption system and a 12 volt compressor system? Now that would be something to consider but I wouldn't want to pay for it.

This is what I have in my Outfitter Apex 9.5 truck camper.
Novacool 7.5 CU Refrigerator 12vdc/120vac (Danfoss compressor)
Does a good job.
I've been out for a week in a canoe and come back to find I still have ice.
Running off two 6v golf cart batteries with 285 watts of solar (95 watt at the time of that trip).

Kevin

Has anyone heard of an aftermarket fridge cooling system causing a fire?

I have a 12v 10cu' fridge in my 5th wheel.
My observations.
It runs off shore power, the house battery, or my trucks 12v power to the camper. I always arrive at the campsite with full camper battery and always travel with the fridge on and loaded with food and beverages. We stock up at home before we leave.
It keeps my food cold/frozen without issue, except once. I think it went through a defrost cycle, but I haven't researched to see if that is an option on the unit. Could be that I had it set too low after a campout and everything thawed? I was playing with temp settings.
The fridge has more than enough space for a week for my wife and I. Plenty of space for an extended weekend with my son and grandsons. Including enough space for adult beverages.

Only issue I have experienced is a noisy fan on occasion. Nothing the TV or stereo couldn't drown out on low volume. However it got annoying in the middle of the night one time while I slept on the jack knife couch. I got up and turned the temp up so the fan would stop running. Wish I could stop the power converter fan from running in the middle of the night. It annoys me as well. However the fan noise is music to my wife's ears. I was on the jack knife because the freight train she was mimicking in her sleep was keeping me awake. I didn't sleep well that night. lol

As for a energy hog, I'm not convinced. During a July campout (90+ degree temps) we had a severe storm blow through in the early am and lost power to the campground. Opened the camper windows, made breakfast, turned off all lights, loaded up the boat, the grandkids and headed to the lake by 8am for the morning of fishing, swimming, and boating. Came back to the camper for lunch, ate, loaded the boat, the grandkids and headed back to the lake for the afternoon. Got back to camp at 5pm to cook dinner. Still no power in the campground, however rumor said it would be less than an hour before it was restored. When power came back on, all the food was still frozen with no signs of thawing. My battery showed 3/4 charge. I only have idiot lights, no meter. The battery is a single group 24 deep cycle battery, standard issue nothing fancy. 

I prefer the 12v fridge to other options. Less moving parts, less to break and repair. Plus it works great.

I recommend dual liquid propane / normal 120 volt AC but it depends on how much "off grid" you do.

"DC only" refrigerators cost less but the ability to use LP when disconnected from AC gives you more "off grid" time verses batteries unless supplemented properly and mother nature cooperates.

A standard eighteen gallon LP tank will run a typical eight square foot refrigerator / freezer "off grid" for months.

A standard eighteen gallon LP tank...

Click to expand...

You've made me curious... what "standard" is that?  An 18 gallon tank would have about 75 lbs of propane if the 18 gallons is LP capacity (80% of the WC).  I'm guessing you are talking about the fixed (ASME spec) LP tank size that is fairly common in larger class C's and smaller class A's. Larger A's often have 24 or even 30 gallon tanks.

A pair of 30 lb tanks found in many medium & large trailers would be a bit less, around 15 gallons for the pair.

Back2PA said:

Has anyone heard of an aftermarket fridge cooling system causing a fire?

Click to expand...

Compressor driven refrigerators use standard Freon refrigerant, not the flammable ammonia-hydrogen mix used in absorption units so there's no danger of a refrigerant leak catching fire.  The only fire risk is the remote chance of the compressor motor or something else shorting out and pulling too much current through the feed wires, which is why there's a fuse in the circuit.

Lou Schneider said:

Compressor driven refrigerators use standard Freon refrigerant, not the flammable ammonia-hydrogen mix used in absorption units so there's no danger of a refrigerant leak catching fire.  The only fire risk is the remote chance of the compressor motor or something else shorting out and pulling too much current through the feed wires, which is why there's a fuse in the circuit.

Click to expand...

Sorry, should have made my question clearer:

Has anyone heard of an aftermarket absorption fridge replacement cooling unit (e.g., "Amish Cooling Unit") causing a fire? I'm wondered whether these replacement units, being newer and supposedly more robust, would be less prone to the leak/fire issues.

Though there is a lot of yammer about Absorption cooling units causing fires.. It is actually fairly rare.. Mice eat wires Outlets get overloaded (the uni-box outlets are not all that robust) and other causes. are equally if not more common.  I've seen a couple of RV fires. both were ENGINE fires. (one was a Pickup and trailer. Smoke damage to the exterior on trailer Pick up was totaled)    My OEM cooling unit failed (leaked) no fire that we could tell but the evidence was clear to the tech and to me once she pointed it out... THe new unit is an Amish Built and it's too new to fail (less than 6 months) .

Expensive summer. New floor in big slide out, New cooling unit, Supper for the Tech (After the cooling unit install I did not feel like cooking or driving so I cut a deal, She drove. I paid, She's nice but not other than business date nice). Plus many doctors  Oh well. Survived.