# Dometic 2300 fridge



## vicker (Jul 11, 2003)

I have access to a Dolmetic 2300 fridge from a junk camper. It is not feasable to use 12v is it? Will this thing work for me on propane? Is it efficient or am I wasting my time?
Thanks in advance,


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## Jim-mi (May 15, 2002)

Up front I don't know that unit.
But if its at all like the units I've seen in *campers* . . .they have darn little insulation in them . . .therefore they are not much of a bargin (meaning free) because you will use lots of fuel (propane or electric) to keep anything cool\cold.

Check to see how thick the side walls are on that unit . . . . . .good efficient fridges have 4 + inches of insulation.........


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## Windy in Kansas (Jun 16, 2002)

For starters check to see if this is one of the Dometic units that was on the major recall list.

Some of the older small units tended to crystalize something in the lines near the burner which in essence prevented proper circulation of refrigerant. I don't know that first hand, only what I was told by a serviceman in the 1970s.

Would you be wasting your time, not in my opinion. While such units have little capacity and have slow recovery time they are usable with their quirks. 

I don't know your means for charging a battery but the draw shouldn't be real large.


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## SolarGary (Sep 8, 2005)

Hi,
The propane powered fridges are not efficient -- they use a lot more energy than electric fridges. If it were me, I'd pass on it, and try to find an energy star electric fridge.

Gary


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## Calvin Wiles (May 14, 2008)

For Solar use it sure helps to have a well insulated Refrig. It will sure save your battery resources if your are off grid. Good insulating can cut the refrig. run time in half.


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## vicker (Jul 11, 2003)

I'm pretty sure I can add insulation, and it is free. I would install it in a cabinet like setting and insulate it well. I supopose its worth it for the money.
Once I get my power system up, I plan on going with the chest freezer converted to fridge route.


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## mightybooboo (Feb 10, 2004)

The one in our RV works very well.But not on 12v. The 12v setting is for kinda/sorta cooling.Beats turning it off but sure doesnt do much on cooling either.

Use it on 12v? Not if our unit is any indication. Even says in the manual 12v isnt much for cooling.


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## vicker (Jul 11, 2003)

Yeah, I think they use like a glowbar type thing when working on 120 0r 12v not efficient with either, but I think they are ok on propane.


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## mightybooboo (Feb 10, 2004)

Ours is super cold on 120 or propane. 12v is a whole 'nother creature.Have no idea about how efficient but it works very well and beats ice chest.

I really like it a lot actually.


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## artificer (Feb 26, 2007)

Looking at this website  it looks like its the standard ammonia absorption refrigerator. If so, then 12V is not a good choice.

For years if you wanted any cooling without electrical power, you had to use propane to heat the ammonia absorption refrigerator. If the unit was a 120v/12V/propane unit, it just means that it used a 120v heater, a 12v heater or the propane heater to power it. 

When you're connected to the grid, the 120v can provide a lot of power, so it would work well. Same with propane. The unit has to be level, and in good condition. If it is, then they work fairly decently.

I don't know the sizes of the 120v and 12v heater elements on the unit, but you can't afford to power it with solar. Ammonia absorption heaters have a COP of less than 1, compared with compressor systems with at least a COP of 3.

That means for every BTU of heat you want to pump, you need a BTU of energy. A BTU is 0.2929 watts. A typical refrigerator/freezer has 350BTU of cooling. So it would use 88watts for cooling. This is a best case scenario, and the fridge will probably use 3 times as much power. 7.3 amps, or 175amp hours per day. Thats one major solar setup. a 175w solar panel runs around $800. You need several panels/chargers/batteries to run this system. 

Short answer: Not efficient, unless propane/natural gas is cheap. (Hello Texican  )

For comparison, you can get a 12v chest freezer or refrigerator that only takes 100 watt*hours per day. It costs $1000, but in the long run it should save money.

I picked up a 4.7ft^3 freezer from Menards a while ago. It starts out drawing 115watts, which then tapers off to 89 watts. I haven't let it freeze and stabilize, and then get power usage readings since I run it on a generator. Once I get the forklift battery out to the property, I'll hook it up, so it has power continuously, and monitor the power it uses. For $135 it was a decent buy. I might get another one, and convert it to a fridge. Should use even less energy. I'll probably add insulation to the outsides as well. This freezer has the external coil, so I can insulate at least 5 sides, and most likely squeeze some in on the 6th side. If I can boost the 2 1/2" already there to 4 1/2", I think it will compare favorably with the Sudanzer.

Just found a site  that says an older refrigeration unit takes twice as much propane as a new unit. They have a 10ft^3 unit that uses 1.5lbs/day. So 1/2 the size but double the useage still gives 1.5lbs/day. 22,000btu/lb, so 33000btu/day, or 9665watt*hours/day.

Thats 402watts all day long. If you say the propane burner is only 50% efficient, then you only need 201 watts of power continuously, or 17amps at 12v. Not going to happen, unless you have a generator or engine running already.


Michael


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