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View Full Version : Dometic Compressor RV Refrigerators?


goodellj
07-20-2018, 04:26 AM
I am hoping someone can tell me about their experience with converting to a Dometic refrigerator with compressor, the 8 cu ft DMC2841RB or the 6 cu ft DMC2641RB. These are described as operating on 110 volt AC or 12 volt DC, switching automatically as needed. This is a lot different than the 'household' refrigerators I have read about and described in this forum, since these Dometics are designed for RV's to replace an RV refrigerator with little or no space modification, and no special electrical needs beyond what was already available for the old 2-way or 3-way RV refrigerator that it is replacing. How did it fit? How well does it work? Is it powerful on 12v and 110v like you would expect a compressor refrigerator to be, not 'weak' like an absorption refrigerator? Does the cold air circulate well inside? Does it operate on a thermostat like your home refrig? Am I correct in my understanding of how they operate? I have read numerous accounts in which users have hunted and found a small apartment sized refrigerator that they either can fit or modify to fit, researched and found a suitable power converter, and vented and anchored the appliance and so on. I am not looking for more info on reverse engineering household units unless they fit perfectly, work perfectly, without modification, and don't forget the converter and refrigerator model numbers (but thanks anyway).
PS: I also cannot find any ratings or reviews by users for these Dometic units. None of the merchants who sell it have any user reports whatsoever.

bill-e
07-20-2018, 06:01 PM
Edit: so rereading your question I might not have what you're looking for. Mine is a standard compressor/propane unit. It does not run just on 12v.

I have the 8cf unit and I think it works great, very cold both on AC and 12v. 12v operation is really propane operation. I go dry camping a lot do I have used it a bunch The thermostat is the standard sensor on the cooling fin that you slide up or down to control the cold. Lots of folks use fans but we've not seen the need for one. When we go to a campground the fridge is usually chock full and everything stays cold. We keep our fridge on all summer long as it always has food in it so that may help also as the food gets a longer soak time at cold temp....it certainly keeps my beer cold and everything in the freezer is rock solid frozen.

gearhead
07-21-2018, 02:55 AM
^^Bill I think you have the regular old style RV fridge.
goodellj is looking for feedback on the new compressor style that doesn't have propane.
I looked on the Dometic website and can't make heads or tails of it. All I saw was expressed in liters. I found something else to do fairly quickly.

travelin texans
07-21-2018, 09:07 AM
My ? is why not the standard rv fridge with LP or 120 volt?? A 12 volt fridge, in my opinion, would require a bank of batteries with solar panels, shore power or generator running. Of the LP items in a rv the fridge uses the least LP of all the others. The standard rv fridge requires 12 volts to operate the control board, but will not run off 12 volt alone.

goodellj
07-27-2018, 02:23 PM
My reason for considering the Dometic compressor refrigerator is that it should have much stronger cooling power than an 'absorption' RV refrigerator. I have a Norcold N811 which is supposed to be a 2-way unit, 110v and propane. However, it does not cool on propane despite my best efforts to trouble shoot it. I had an RV tech look at it with a camera on a snake and he also could not find the problem. So I currently travel with no refrig running, which isn't a problem except for now, in July, with 90 plus degree temps. When I arrive at my destination I wait a long time for the weak absorption fridge to finally get back into the safe temperature range. If I am going to buy a new refrigerator, I thought I might consider this as an alternative. For the money, I will also take another run at the propane function by taking the stack apart and I will start using freezer packs in the refrig compartment when we travel.

chuckster57
07-27-2018, 05:47 PM
What did the tech look at with his scope/camera? If it’s cooling properly on AC, then diagnosing/ fixing the LP side should be fairly easy.

goodellj
07-29-2018, 03:52 AM
What did the tech look at with his scope/camera? If it’s cooling properly on AC, then diagnosing/ fixing the LP side should be fairly easy.
I guess it's one of life's mysteries. On propane we had good clean blue flame, camera snake showed clean chimney flue, we felt heat coming out the top of the flue, but no cooling effect on the fridge. I ran it on propane for 3 days and inside temp stayed the same as the outside temp!

chuckster57
07-29-2018, 04:02 AM
Did he use a manometer to test gas pressure? Was the baffle in place?

JRTJH
07-29-2018, 10:02 AM
Did he use a manometer to test gas pressure? Was the baffle in place?

That was my question as well: Did the baffle bounce out of position?

chuckster57
07-29-2018, 10:54 AM
If he stuck a camera down the stack, he had to remove it. If he went UP from the bottom he had to remove the burner assembly. FIRST step in diagnosing a refer not cooling on LP is to test pressure using a nanometer at the gas valve.

From his statement that it cools on AC, it almost has to be gas pressure, burner placement or missing baffle.

JRTJH
07-29-2018, 01:20 PM
Agreed. The entire cooling system is the same in either operation (with the exception of the heat source). So if it works on electric, it "has to work" on LPG, if the heat source is operational.

ptooti
08-01-2018, 12:00 AM
Thought ??? absorption refers are supposed to run at no more than 3 degrees off level it can cause problems with the fridge we always put frozen water bottles in top and bottom when we are in motion and don’t travel with the fridge running temperature is maintained till we turn it on again

chuckster57
08-01-2018, 01:39 AM
Thought ??? absorption refers are supposed to run at no more than 3 degrees off level it can cause problems with the fridge we always put frozen water bottles in top and bottom when we are in motion and don’t travel with the fridge running temperature is maintained till we turn it on again

The 3 degree rule only applies to a stationary fridge. When in motion (going down the road) it doesn’t matter, everything is getting shaken so nothing “puddles” in the corners of the cooling unit.

larryflew
08-05-2018, 10:36 AM
Just a side note regarding compressor running on 12 volts. NEVER GONNA HAPPEN. Winding needed for that would make the compressor the size of a 5th wheel hitch assembly. Didn't bother going to Dometics site but has to be something else going on rather than compressor running on 12 volts.

larryflew
08-05-2018, 10:43 AM
Ok, it is compressor running on 12dc and drawing 10 amps so yes it has huge windings but in a tiny compressor that is probably close to as large as regular. Draws 1 amp on 120ac. Not sure if that equates to much better than absorption but it's gonna be a battery sucker if your dry camping at all.

smt0954
08-06-2018, 06:05 AM
if you're not going to replace the frig (and I don't blame you - they are quite expensive), how about purchasing a 2k watt genset / inverter model, plugging it up to your camper while going down the road.
the inverter types should run around $500 and non inverter types around $200 - $300.
I have the Jayco Eagle 317RLOK fifth wheel. I run a Champion model 100302 Digital Hybrid portable genset in the back of my truck. Bought from Home Depot for $650. It allows me to run refrig and 1 15k AC while going down the road. It's around 82lbs, so pretty easy for me to handle. The great thing is that while traveling. the inside stays in the mid 80s (with 95plus outside temps). So once I hook up to shore power, both ACs cool us down quicker.
just a thought
be safe out there!

Bob Landry
08-06-2018, 06:35 AM
To get back to the OP's question... There are several manufacturers of dual voltage(110V/12V). They are widely used in, but not limited to marine applications. All that I know of are now using the Danfoss compressors and electronic modules and the systems are very reliable. In the last 15 years I think I have replaced one compressor. The compressor draws around 5 amps when running. If both AC and Dc are available to it, it defaults to 110VAC and switches to DC when the AC source is removed.
I'm not sure how the cutout requirements would apply. You would have to pull the existing ox and get a measurement and then find a box that would fit the opening. If you have extra room to make adjustments to the cutout size, that gives yo a little wiggle room to play with.
The compressor uses a split phase low voltage. The