12V Compressor Refrigerators

[lwahls]

Have had two three-way absorption (three since we had to replace one - $800). We now restrict ourselves to electrical sites with Jayco van (getting old.). Prefer compressor - quicker cooling and much better in hot weather.

[photochefs88]

The isotherm freeline 115 elegance is now turn-on inside my Roadtrek for a month seating on my driveway power by Solar Panel, battery level is alway at 85% in the morning. My Dometic model # RM 7401L 3-way refrigerator will run out of battery after 2 days! Make sure to buy the gas-cap when removing Dometic 3-way refrigerator, the old propane switch will not 100% shut it off. I only have isotherm freeline 115 and Nova Kool RM4500 that will be good fit in my space, the Dometic compressor 12V/115AC draw Double the current!

[booster]

Originally Posted by photochefs88

The isotherm freeline 115 elegance is now turn-on inside my Roadtrek for a month seating on my driveway power by Solar Panel, battery level is alway at 85% in the morning. My Dometic model # RM 7401L 3-way refrigerator will run out of battery after 2 days! Make sure to buy the gas-cap when removing Dometic 3-way refrigerator, the old propane switch will not 100% shut it off. I only have isotherm freeline 115 and Nova Kool RM4500 that will be good fit in my space, the Dometic compressor 12V/115AC draw Double the current!

We also have had an Isotherm for a long time. Nice and efficient for sure.

We don't know what your battery bank size is, but 85% seems a bit low if it was full after a day of sun. Our overnight is normally under 10ah as it is much cooler outside. (our compressor and condenser vent to the outside). We also have 300w of solar and would be in need of about 25ah of recover in the morning on average while camping and using more than just the frig. Decent sun and we are full before noon most days. How many amp hours are you down in the morning with just the frig running?

I think there is an misleading spec in the Dometic literature, which I just looked at. They list something like 6 amp "rated" DC spec, but under AC they have a 40 watts spec. They look to use the same compressor/condenser module as the Isotherm, so it would likely be a Danfoss BD35 and use right around that 40 watts running at mid high speed setting. That is in the 3.5amp range and more typical. Rated would probably be the max ever amps and they have a quick cool setting the would run the compressor at full speed, so makes sense.

[photochefs88]

My 4 years old battery bank are not in very good condition, it have went dead a few time because of the Dometic 3-way refrigerator left running, which degraded it battery capacity. The Dometic 3-way refrigerator will not run, if my vehicle is not level and in the windy city of Chicago, the flame won't stay lite while parked!

[Bud]

Originally Posted by photochefs88

My 4 years old battery bank are not in very good condition, it have went dead a few time because of the Dometic 3-way refrigerator left running, which degraded it battery capacity. The Dometic 3-way refrigerator will not run, if my vehicle is not level and in the windy city of Chicago, the flame won't stay lite while parked!

The flame 'did' blow out driving 50+ or in gusty wind conditions, and parked in high side winds. Had to park do a 180 and park the other direction. 05/04 190P Roadtrek. No longer, I can drive 75 and stay parked.

I suggest closing off the bottom air vent with gorilla tape or whatever. I also have a thin sheet of sheet metal between most of the air vents and flame. I think that it would be worth some experimenting.

[rauscs]

Hi Booster, Do you have the isotherm freeline 115 elegance? It is hard to tell if that will fit in our 2004 190P. Steve

[photochefs88]

The Isotherm fridges feature voltages ranging from 80 to 260 volts including 115 volt and 220 volts both 50 and 60 Hertz. ....Remember that the Danfoss electronics are designed to shut off when voltage drops below 11 volts. (no dead battery to worry)!
I love ice cream during the hot summer, but the Dometic 3-way refrigerator won't keep the the ice cream hard!

[eric1514]

If you're replacing an absorption fridge with a compressor type in the same exact location, what are the pros and cons of leaving the original vents open and unsealed and using them with a fan or not to vent the unit?

[Bud]

Originally Posted by photochefs88

The Isotherm fridges feature voltages ranging from 80 to 260 volts including 115 volt and 220 volts both 50 and 60 Hertz. ....Remember that the Danfoss electronics are designed to shut off when voltage drops below 11 volts. (no dead battery to worry)!
I love ice cream during the hot summer, but the Dometic 3-way refrigerator won't keep the the ice cream hard!

Seems that something is not quite right with your Dometic.

The Dometic in my 05/04 Roadtrek 190P was LOUSY when I purchased it. Nothing wrong with the refer, it was the lousy Roadtrek installation. I think that was true with all of them, so how bad is determined by the owner after purchase. I travel with only one temperature sensor, not in the freezer as the freezer stays happy.

What have you done to solve the problems? What B and Dometic?

[photochefs88]

After 3 years, I have replaced the Dometic 3-way refrigerator with Isotherm freeline 115 elegance, the biggest problem is that I can't turn on the Dometic 3-way refrigerator before packing up. I lived on a hill, my street and driveway is not level and the Dometic 3-way refrigerator therefore it won't turn on, once I start driving, it take a long time to cool down, about 1/2 day for normal refrigerator temperature, which my cream for coffee might go bad and on hot day refrigerator temperature inside is at 50 degree.

[booster]

Originally Posted by rauscs

Hi Booster, Do you have the isotherm freeline 115 elegance? It is hard to tell if that will fit in our 2004 190P. Steve

We have a cruise 85 in our 190P, 2007 Roadtrek. it was the largest that would fit at that time, but they have some newer models, so there may be others now that would fit. We had lots of room around it, so I put it on aluminum angles about 5" above the floor, which gave us room to store the always in the way Chevy jack under the frig. We were also able to add and inch of urethane foilboard insulation all the way around the frig which helps the energy use a quite a bit in really hot weather.

The other question just asked was about pluses and minuses of using the outside vents on a van that already has them like our Roadtrek.

For venting the frig, you can use either successfully, but likely not just by dropping it in and using it. We were very early into the compressor frig stuff and learned the hard way, with quite few bumps along the way.

The Isotherm uses the Danfoss combined compressor, condenser, fan setup in the rear top corner, at least on ours. It is built for boats, so the fan blows toward the inside of the van and is designed to take in air right at the floor in the front. The hot air has to turn 180 degrees to head to the top vent in the van wall, but gets sucked back into the fan instead, just looping and getting hotter and hotter. I finally wound up making a duct out of 1/2" foilboard that mounts tight to the fan inlet and extends down to the lower vent on the side of the van. All the rest of the area between the frig and van wall between the upper and lower vents is packed with fiberglass insulation to prevent airflow either way. It works very well and got us to power use as low as when on the bench in totally open air. We have no extra fans to evacuate the air, and when I tested one just to see, the fan used more energy than it saved. We are completely sealed off from the inside of the van, so no bugs or hot air inside.

Upside to venting inside is no cutting when start from scratch, but is less when you already have the outside vents, IMO. It can be tough to get the hot air out of the area behind the frig and most have found extra fan(s) are necessary to get the heat out and efficiency up. The do save more energy than they use in this case.

A downside of the outside vent use is that you need to keep the rain out, which wasn't a problem with the Roadtrek. You also can't get to the compressor and condenser on the Isotherm because the upper vent doesn't come off without removing the window. If the it needs cleaning you need to slide out the frig to inside the van and can be done in an hour or so if you make it easy to remove when you put it in.

A maybe advantage of the outside vent is that the wiring is right there and easy to get to. I found that very handy, as I could install the WattsUp power accumulator gauge there easily to monitor just frig power use.

I think Norcold makes frig that is a bit bigger and uses a compressor on the bottom and conventional rear coils that will fit also. I would assume some venting issues would also be needed with it, including maybe an exhaust fan as it is a gravity cooling setup.

[Bud]

booster, the WattsUP can be used to determine when the refer may need cleaning. If the power required does not go up, cleaning not required - nice feature.

Bud

[booster]

Originally Posted by Bud

booster, the WattsUP can be used to determine when the refer may need cleaning. If the power required does not go up, cleaning not required - nice feature.

Bud

Good idea, I suppose you could even install a connector pair on the frig to power and opposite mating on the WattsUp, so it could just be plugged in when test time came around.

[peteco]

Originally Posted by photochefs88

The Isotherm fridges feature voltages ranging from 80 to 260 volts including 115 volt and 220 volts both 50 and 60 Hertz. ....Remember that the Danfoss electronics are designed to shut off when voltage drops below 11 volts. (no dead battery to worry)!
I love ice cream during the hot summer, but the Dometic 3-way refrigerator won't keep the the ice cream hard!

My Dometic RM2554 3-way typically has freezer temps 5-deg or lower so hard ice cream has not been a problem. It is the fridge part that struggles. When the fridge fails I will likely replace with a compressor fridge. Right now the only 2 that fit are the Norcold that Roadtrek uses and Vitrifigo. Both have less than stellar reviews. I wish NovaKool or Isotherm made a size to fit.

Recess depth 24.02 "
Recess height 42.64 "
Recess width 23.90 "

[eric1514]

If I buy a fridge like the Novacool R3100, is there a compelling reason to pay extra for the ability to run off 110v? I figure if I'm plugged in then the batteries are being charged anyway. Am I overlooking something?

[avanti]

Originally Posted by eric1514

If I buy a fridge like the Novacool R3100, is there a compelling reason to pay extra for the ability to run off 110v? I figure if I'm plugged in then the batteries are being charged anyway. Am I overlooking something?

There is no reason whatsoever to purchase such an option. All it is is a power brick that converts 120VAC to 12VDC. Your van no doubt can do that already.

[eric1514]

Originally Posted by avanti

There is no reason whatsoever to purchase such an option. All it is is a power brick that converts 120VAC to 12VDC. Your van no doubt can do that already.

Thanks for confirming what I thought.

[RossWilliams]

I unplugged my refrigerator from 120 so that it always uses 12 volt even when the inverter is on. Refrigerators don't use that much power, but you might want to make sure your electric system will handle the conversion on shore power. I would assume that isn't a problem with a 2015 Travato, but it might be for people with other rigs.

[booster]

Originally Posted by avanti

There is no reason whatsoever to purchase such an option. All it is is a power brick that converts 120VAC to 12VDC. Your van no doubt can do that already.

I would totally agree, with the possible exceptions that probably wouldn't ever happen anyway, like if there no 12v power to the frig area but it has 110v there, or if you have a lithium battery setup that has full charging shutoff so no way to run off 12v without using battery capacity and you are saving battery capacity for some reason (many newer lithium setups do this, but are so large that the 30ish ah per day is inconsequential).

[GeorgeRa]

I have AC/DC option and use it occasionally. My system allows me to run the fridge only on AC via main panel, DC is off by Intellitec main disconnect, all other AC devices are off. We use this option after a trip and before emptying or if we need extra fridge. Could I live without this option, yes.

However, there is one disadvantage of AC/DC option if you plan to replace the electromechanical capillary thermostat with an electronic Isotherm Smart Energy Controller from Isotherm. Electrical connection is not straight forward but doable. https://www.westmarine.com/buy/isoth...SABEgK0G_D_BwE