Refrigerator

[Infohound]

I have a Dometic 3 way absorption refrigerator. We are very dissatisfied with its performance. Actually, we have had THREE OF THESE Dometic refrigerators. All have had the same issues! If the outside temperature gets 85 or higher, it will not keep our food cold enough to be safe. We are in discussions to replace it with a compressor refrigerator. Our service person says our only option is to install 200 volt lithium battery and install a compressor refrigerator. EXPENSIVE FIX! We boondock a lot. He says the lithium battery would give us about two days of service before needing recharging. He says we would need to run our generator 8 to 12 hours to fully recharge.

I am writing to ask you for some direction and advice with this issue. Do you know of any refrigerator resource people or service centers to consult with. I need expert advice on doing this conversion the right way. It is an expensive conversion so I would like it done correctly.I live in Louisiana.

[hbn7hj]

First it is not a 200 volt battery. It is a 200 amp hour lithium battery. It does not take 8-12 hours to charge a 200 AH lithium battery. Probably less than an hour, certainly less than two with the proper charger.

Go slow on this till you understand it all.

First we need to know the Dometic model you are trying to replace.

As mike says below, it is a $2000 project to add lithium power to run a compressor fridge. You have to buy the fridge in addition.

[mkguitar]

this is a commonly expressed concern


I live in Phoenix


I know I can get my 15 year old 2354 fridge to 60º below ambient on gas and keep it there.

at 100º that's marginal but when we camp we try to go "nice places" and it's easy to maintain cold when camped on AC or gas and it's only 80º and in the 50's or 60's at night


driving ? the 12 volt is marginal.
on a long drive we rotate cold packs from the freezer section to the fridge and that helps

we have a small internal fan in the fridge

we have 3 fans on the fins which can be used independently to increase efficiency- shed heat out teh vent. I've also added a piece of sheet steel to direct the air flow thru the fins- originally much of teh air could go past

if the van is level enough for us, the fridge seems happy

I maintain the fridge as per the manual, pretty easy to clean the stack and set the igniter gap

my older van's electrical system won't support a compressor fridge and I'm not interested in a ( guessing) $2000 project.
Perhaps if my fridge quit entirely

If you are done with the old fridge, please share the upfit to the new unit


Mike

[Want a B]

I had my Dometic 2-way (120 AC/LP) converted (JC Refrigeration in Shipshewana, Indiana) to 12 DC compressor.

My coach has two, 12 volt batteries. Age of batteries and AMP hours is unknown. They are 575 CCA each if this is any help.

Night before leaving home refrigerator was turned on.

The morning of leaving for the camp site the refrigerator was cooled down to operating temperature.

I arrived at my camp site at 9 AM with fully charged batteries.

Upon arrival a portable 200 watt solar panel was connected to the coach batteries. Cloudy day, solar panel was moved twice during the day for efficiency.

Refrigerator draws 100 watts when the compressor is running.

8 AM the next morning by batteries were at 50.1% capacity.

My testing above was with basically an empty refrigerator. I had 6 bottles of water in it.

IMHO depending on your refrigerator size and efficiency, your battery capacity and the cooperation of the sun your goal might be possible.

[peteco]

Infohound,
I see from your profile that you have a Roadtrek 210P. I have a 2006 210P. Over the years I have owned it I have learned several things about absorption refrigerators and the installation in the 210P. I have a writeup on several factors that can improve performance. I would try these before giving up on your present fridge and going the 12-volt compressor route.

https://www.classbforum.com/forums/f...ance-8484.html

[Infohound]

Refrigerator model is RM2554.

[hbn7hj]

The RM2554 cannot have the absorption cooling unit replaced with a compressor cooling unit. The Nova Kool 3800 is a compressor replacement, I think, and there are other brands. Isotherm is one.

The company that makes replacement compressor cooling units does not make units for the short refrigerators like the RM2554. The compressor units require 8” behind the units for the compressor and class Bs just don’t have it. Check your van and you will find you don’t have the space.

[DWorrell3]

Originally Posted by Infohound

I have a Dometic 3 way absorption refrigerator. We are very dissatisfied with its performance. Actually, we have had THREE OF THESE Dometic refrigerators. All have had the same issues! If the outside temperature gets 85 or higher, it will not keep our food cold enough to be safe. We are in discussions to replace it with a compressor refrigerator. Our service person says our only option is to install 200 volt lithium battery and install a compressor refrigerator. EXPENSIVE FIX! We boondock a lot. He says the lithium battery would give us about two days of service before needing recharging. He says we would need to run our generator 8 to 12 hours to fully recharge.

I am writing to ask you for some direction and advice with this issue. Do you know of any refrigerator resource people or service centers to consult with. I need expert advice on doing this conversion the right way. It is an expensive conversion so I would like it done correctly.I live in Louisiana.

An absorption refrigerator cannot cool below about 20 degrees ambient. I.E., if I am Lubbock, TX, and the temp is 107 degrees, the frig is not going much below about 80. We've lost a lot of good with the absorption. We replaced it with a Noval Cool, which has a built in inverter, ergo, it will run on ac or dc. I can run the Nova Cool 48- 60 hours on the coach batteries and our RT does have a generator. Failing that, I can recharge my coach batteries in 15- 20 minutes of running the van engine. Make the move. Absorption just doesn't work. Dave W

[GaryG]

I have a 2011 Roadtrek that I am the 4th owner of. It is a Sprinter, but it sounds like there are similar issues. I had the same issue with the fridge initially, especially when operating with LP gas. The issue is the reduced height of the top outside vent due to the location of the bottom of the side windows. This causes heat to build up which makes the cooling far less efficient. There are two small computer fans connected to a heat sensor thermostat on the outside coil to help blow out the hot air. This helps, but the fans cycle on and off and the heat still builds up. The cycling on and off in warm weather can also be annoying when one is trying to sleep.

What I did was install a small $2.99 automotive toggle switch on the front panel of the fridge. The switch jumps the thermostat so that when in the "on" position, the fans fun continuously. In the "off" position the fans cycle on the thermostat.

During warm weather, when using LP gas or when starting up the fridge when its been off, I leave the fan on. It works like a charm. I have a bigger problem with food freezing now, so I never run the fridge on high any more.

If this sounds helpful, let me know and I'll send you pics in a few days.

[avanti]

Originally Posted by DWorrell3

We replaced it with a Noval Cool, which has a built in inverter, ergo, it will run on ac or dc.

Just to be precise:
NovaCool compressor fridges run on 12VDC native. It isn't the they have a "built in inverter". Rather, it has a built-in power brick that converts 120VAC to 12VDC.
There is no real point to this feature in an RV for most people, since your coach's converter does the same thing.

[MsNomer]

Originally Posted by avanti

Just to be precise:
There is no real point to this feature in an RV for most people, since your coach's converter does the same thing.

My Engels (I have two) have this feature and I find it very convenient. I wouldn’t want to be without it.

[Infohound]

Originally Posted by DWorrell3

An absorption refrigerator cannot cool below about 20 degrees ambient. I.E., if I am Lubbock, TX, and the temp is 107 degrees, the frig is not going much below about 80. We've lost a lot of good with the absorption. We replaced it with a Noval Cool, which has a built in inverter, ergo, it will run on ac or dc. I can run the Nova Cool 48- 60 hours on the coach batteries and our RT does have a generator. Failing that, I can recharge my coach batteries in 15- 20 minutes of running the van engine. Make the move. Absorption just doesn't work. Dave W

Do you know the model number or cubic feet of the old refrigerator that you replaced? Also, do you know the Nova Cool model number of your new refrigerator? Did you make any modifications to the install or just removed the old and put in the new? Thanks.

[rtbill]

The fridge can be made to work quite well.

The primary problem is Roadtrek's lousy installation of the fridge. In a larger RV the top vent is on the roof. The chimney to the vent creates natural convection over the coils, particularly the finned coil at the top of the fridge which rejects most of the heat. In a Roadtrek the finned coil sits in a stagnant pocket with meager convection. The solution is fans to force air through the rear of the fridge combined with directing the air over the finned coil.

On our 200 I installed five computer fans on the lower vent cover drawing air through the lowest slot. I taped closed the other two slots and any small openings around the fan.

I also taped closed the lower two vents in the upper vent cover. This directs all the air over the finned coil.

With the fans running the fridge maintains 35F on AC and DC. I instrumented and tested the fridge on days up to 85F. The heater duty cycles were 60% on AC and 75% on DC. The unused duty cycles imply the fridge should stay cold in temperatures up to 100F and maybe more. The fridge stays perfectly cold on DC when driving. The fans draw 200 mA, saving more electricity than they use compared to running the fridge without the fans.

[avanti]

Originally Posted by MsNomer

My Engels (I have two) have this feature and I find it very convenient. I wouldn’t want to be without it.

The only scenario I can think of (as George has pointed out in the past) is that it may be useful for those who wish to store the vehicle for long periods with the fridge running. It permits one to do so without powering the coach's large AC/DC converter/charger.

Is that what you do?

[MsNomer]

My Engels (one set for fridge, the other as a freezer) stay on 24/7, even when parked in our shaded driveway. Also, it's good that the units are isolated and continue to run when the DC system is down for upgrade or repair.

[RedPanEd]

Replaced the Dometic 2310 in my 99 RT P190 with a Novakool R3800. I did not make any changes to the rest of the system ( I rarely boondock). The cooling performance is FAR superior to the Dometic. On a 90 degree day it dropped the temperature in the fridge to 35 degres in less than 3 hours. To replace the Dometic with the Novakool required VERY little cabinet mods. I bought the 12v/120v version only because it was the only one the supplier had in stock and everyone else quoted 3-5 month delivery. I would nave bought the 12 volt only otherwise.

[Infohound]

Anyone know which compressor refrigerator brands and models will fit in the Dometic RM 2554 space with out modifications? I have a Roadtrek 210 popular. Thanks.

[peteco]

Originally Posted by Infohound

Anyone know which compressor refrigerator brands and models will fit in the Dometic RM 2554 space with out modifications? I have a Roadtrek 210 popular. Thanks.

Back in 2015 I came across the Norcold DC558 compressor refrigerator that Roadtrek had started to install in the 210. As I recall it was the same size as the RM2554. It turned out I was able to nurse my gas absorption fridge for another 5 years before it died in 2020. When I looked again for the DC558 I had trouble finding a source. Also there were some reliability concerns in the few reviews I could find. I also considered the Vitrifrigo C130, but that was a little smaller and would have required cabinet mods. Then there is the NovaKool R5800. Others have put this in the 210 and have been happy with it. Again, that requires some cabinet mods.

Ultimately I decided I didn't want to go through the electrical system upgrade needed to support the fridge for boondocking more than a couple days. For my needs that meant lithium batteries and associated charging system, controls, and wiring upgrade.

Also, I had learned how to get good performance from the RM2554 so I purchased a new one and installed it.

I see you are in Louisiana so you face more of a heat challenge than I do in Virginia so it makes more sense to go compressor. I will say that if my RM2554 were to fail in the next few years I will probably bite the bullet and go compressor, probably the Vitrifrigo due to its larger freezer size.

Here is a discussion on the Norcold from 2015.

https://www.classbforum.com/forums/f...ions-4014.html

[Blueboy1]

Originally Posted by RedPanEd

Replaced the Dometic 2310 in my 99 RT P190 with a Novakool R3800. I did not make any changes to the rest of the system ( I rarely boondock). The cooling performance is FAR superior to the Dometic. On a 90 degree day it dropped the temperature in the fridge to 35 degres in less than 3 hours. To replace the Dometic with the Novakool required VERY little cabinet mods. I bought the 12v/120v version only because it was the only one the supplier had in stock and everyone else quoted 3-5 month delivery. I would nave bought the 12 volt only otherwise.

I did the same swap, Dometic 2310 to Novakool R3800 4 years ago in my 1996 Pleasure-Way STW, and lived happy since. Easy fit in the opening, just added rigid foam insulation around the unit and sealed everything. The setup is powered by a 250watts solar panel and a 225A Trojan deep cycle battery and the system, is very well balanced. Average power draw on the battery for the night is around 150 watts, and the battery is back to full charge around 09:00 Am on a sunny day, her in eastern Canada. By the way I have the 12vdc only model and we are boondocking 90% of the time.