Rv fridges any good?

[maxwolfman]

I'm looking at purchasing a 13 foot scamp. I read online that the RV refrigerators in those is nothing more than a box to keep drinks cool. That it really doesn't work very well as far as a fridge. Anyone have experience with this? Could I replace it with a dorm refrigerator?

[floyd]

Originally Posted by maxwolfman

I'm looking at purchasing a 13 foot scamp. I read online that the RV refrigerators in those is nothing more than a box to keep drinks cool. That it really doesn't work very well as far as a fridge. Anyone have experience with this? Could I replace it with a dorm refrigerator?

Reading your title line.. I just want to say NO, its not, and suggest that you may have confused it with the toilet.
The fridge is the box under the stove and is for food storage while keeping cool drinks in the toilet would be inefficient at best and unsanitary at worst.
This problem could be exacerbated further if you misconstrued the proper use of the fridge!
Sorry, just kidding


For real though...

The provided fridge generally works great on propane or 110V and not so good on 12V. Overall they are reliable and efficient.
Depending on the model or year of production many of them have no freezer compartment though.
Also they have no built in fan for circulation and their small size discourages constant fanning of the door.
It is cooled by cooling the back wall only, so it is important not to over pack the fridge , leave a little space for circulation and it will be fine.
If you must pack it, be sure and put the coldest and freeze tolerant stuff in the back. Fresh produce or such could actually freeze or suffer damage when they are packed against the back wall

As for cold drinks I suggest keeping only a couple of them in the fridge and using a separate ice chest for cold drinks, this works better, leaves more space for perishables and reduces fanning of the door.


Another thing, keep the door gasket clean and undamaged. This will prevent condensation build up inside.

Learn to use the latch on the door while in transit and also its feature to latch the door slightly open during storage, leave it dry and open to prevent mold inside during periods of trailer storage.

[tractors1]

I had a small propane (basically RV) fridge in small shack/house that was probably 30 years old when I moved in (1975) on Maui that worked fine. I was a student at Univ of Hawaii and sampled underwater sensors for a marine project by scuba diving. Last time I stopped by in 2009 it was still working quite well.

[tractors1]

Originally Posted by maxwolfman

I'm looking at purchasing a 13 foot scamp. I read online that the RV refrigerators in those is nothing more than a box to keep drinks cool. That it really doesn't work very well as far as a fridge. Anyone have experience with this? Could I replace it with a dorm refrigerator?

Of course.

[Jon in AZ]

They can work fine, but there are limitations. They are very slow to cool down (and slow to recover each time the door is opened). They have a limited range of operation; I.e. they may not be able to maintain safe temperatures in higher temperatures, especially if there is direct sun on the fridge side of the trailer. The setting has to be adjusted as ambient conditions change. They require periodic inspection and cleaning of the burner (one common cause of weak operation). Big plus is they can run two weeks or more on a single tank of propane with no power.

A dorm fridge is simple, inexpensive, and reliable but has its own significant limitation: it only works when you’re parked and plugged in. It doesn’t work when you’re towing, and it doesn’t work if you’re camping without power (which includes many nice public campgrounds, including most national parks and forests). We’ve had our Scamp 9 years and we’ve only had a power hook-up once. Even when hookups are available (like AZ state parks), the no-hookup sites are much nicer: more spacious, natural vegetation, less like a trailer park (and cheaper).

A 12V compressor fridge is the up-and-coming off-grid RV refrigeration technology, but they cost $500 or so and up (similar to a new 3-way fridge) and typically require upgrading your battery and recharging capacity.

If you do purchase a Scamp with a 3-way fridge, I’ll suggest having it serviced (or do it yourself) and spend at least one season learning its ins and outs. Floyd has made good suggestions. We also keep frequently accessed and less sensitive items (drinks and fruit) in a separate small (ice) cooler to avoid opening the door of the fridge too often. In hot weather making sure the fridge side of the trailer is shaded helps.

After a year you’ll know whether the 3-way works for you, and you’ll also have a better idea of your preferred camping style to select the best alternative if not.

[RogerDat]

If the fridge has the cooling applied to a metal box that forms the freezer compartment one can pack some blue ice or frozen food in there and just like an ice block it will keep the fridge at safe temps throughout a day of traveling. Refreezing solid when one stops for the night.

Works with dorm sized 110 volt, or 12 volt or older propane that don't cool the back wall but cool the freezer box.

The propane do not move heat fast out of the inside they move it steadily. No on off cycle to speak of. Ice cubes on an 80 degree day were possible in my 40 some year old Scamp refrigerator.

Probably biggest down side for a propane or 3-way unit is the bulk or size of unit for given amount of food storage. There is more "guts" behind them and they should have fairly thick walls for good insulation. We had the small unit they put in a 13 ft. scamp and it was used as a cupboard. We had two good coolers that sat at the back of our tow vehicle. One mostly food, one had drinks and food.

Don't count on tow vehicle to have alternator output to keep house battery charged while running evaporative or 3-way refrigerator on 12 volt while traveling. People report arriving with house battery dead despite being hooked to the tow vehicle charging system.

Ice in the coolers went in oval plastic pitchers so we didn't get water in the cooler from melting ice and could pop lid off of pitcher to refill with cube ice. Using this cooler set up was well established from tent camping days and we just never changed it.

I expect we will use the larger 3-way refrigerator in the Scamp 16 as a refrigerator. Probably for food, still keep drinks out in cooler. Get our ice with a scoop out of our 6 gallon water jug that we keep full of ice. After all a single ice cube in ones whiskey glass is just more civilized :-)

[Dan Meyer]

The 'Fridge in my Scamp has to work in some very demanding conditions, relative to the conditions my home 'fridge works under.

At home, the temperature is almost never above 80 degrees, and it always out of direct sunlight. It uses 660 watts of energy to move heat from inside the box to the outside. It never gets bounced around and the contents give it a pretty large thermal mass, evening out temperature swings when you open the door.



Contrast this to the unit in my Scamp. Temperatures can be 95 degrees or higher, with the direct sun baking the unit. It is provided with 150 watts of energy from electric power or 1,000 btu/hr from propane to move heat from inside the box to outside (My 'fridge has no provision for DC power). The capacity is small, and thermal mass is also small causing large temperature swings when the door is opened. Since cooling capacity is low, recovery time is long. It gets bounced around while moving down the road. The rear of the unit is exposed and all kinds of insects and other critters can inhabit this important area restricting airflow.

In my mind it is a wonder that any RV 'Fridge works for more then 3-5 years under the condition provided.

If your 'fridge isn't working very well, crack open the owners manual and review the maintenance instructions. Owners manuals for many RV refrigerators can be found here: https://www.fiberglassrv.com/forums/downloads.php

--Dan Meyer

[Jennifer Minogue]

Camco sells an RV fridge fan that works on 2 D cell batteries. You still can't pack the fridge tightly but I think the fan really helps.

[Glenn Baglo]

I considered a 3-way fridge when purchasing my trailer, but with the limitations of 12V, I ordered a 2-way fridge, AC and propane, and lived happily ever after.

[floyd]

If you are buying new get a Danfoss.
If you think you might not want a 3-way RV fridge
don't pay for one and also suffer two huge holes cut into the side of your Scamp.

[Raz]

Originally Posted by floyd

If you are buying new get a Danfoss.
If you think you might not want a 3-way RV fridge
don't pay for one and also suffer two huge holes cut into the side of your Scamp.

Here in northern New England the campgrounds are in the forest, so solar doesn't help. With propane and no DC required, I'm good for up to 3 nights. With a compressor fridge, I'm one night. So it really depends on where you camp. When I bought my Trillium he really tried to sell me a compressor fridge. Even offered a discount on a generator to go with it.

[David Tilston]

Originally Posted by RogerDat

Don't count on tow vehicle to have alternator output to keep house battery charged while running evaporative or 3-way refrigerator on 12 volt while traveling. People report arriving with house battery dead despite being hooked to the tow vehicle charging system

I'm not trying to be difficult, but I have said this before. The amount of current required to run a 12 VDC heater on most fridges should not be a burden on most vehicles. The wattages on the attached table range from 95 W to 325 W.
Absorption Fridge Heater Wattages.pdf

This would require 8 amps to 27 amps at 12 VDC. The alternator on my 1997 Ford Ranger is the small one that only makes 95 amps, the larger version makes 130 amps. Other than requiring a larger conductor, (#10 copper is good for 30 amps) this should not represent an impossible load on the vehicle. The resistance of #10 copper is 1.03 ohms per 1000'. Assuming that we are talking about a run of 30' from the battery of the tow vehicle to the fridge, or 60' of #10 wire, 60/1000*1.03 ohms = 0.062 ohms. This ignores the resistance of the plug.

The voltage drop that 27 amps would cause is, V = I * R = 27 amps * 0.062 ohms = 1.67 volts. So when the vehicle is running and the alternator is making 14.4 VDC. The fridge should see 12.7 VDC.

I have run #8 copper, (0.654 ohms per 1000') from my battery, (positive and negative) to the trailer plug, and put as much of that as would fit into the screw terminal of the plug. The cable from my trailer has #10 for the positive and negative, and I have run #10 to the fridge.

Why would this not work?

It seems to me that if your battery is dead on arrival at your camp site, then you have a wiring problem. I might go so far as to disconnect the trailer battery, while the trailer is plugged into the vehicle. Then measure the voltage at the fridge. If this is lower than 10VDC, there is something wrong with your vehicle wiring.

[Raz]

Draw the circuit. Two batteries in opposition with a resistor (wire) between the positive terminals and a resistor between the negative terminals . The fridge heater is in parallel with trailer battery. The voltage drop is the difference between the two batteries (KVL) and is independent of the wire size. Take that voltage and divide it by the wire resistance and you have the available current. That has to both charge the battery and supply the heater. Larger wire ( smaller gauge) will increase the total current until you hit the limit of the alternator. Every vehicle is different. And with so much electronics on current vehicles, I suspect the alternator is taxed. While others disagree, I have suggested that the prewired vehicles with small charging wires was intentional to limit that application.

[Glenn Baglo]

The issue with running on 12V is if you leave camp with a depleted battery, you will arrive at your next camp with a depleted battery. The fridge on 12V takes power that would have charged your house battery.

[David Tilston]

Originally Posted by Raz

Draw the circuit. Two batteries in opposition with a resistor (wire) between the positive terminals and a resistor between the negative terminals . The fridge heater is in parallel with trailer battery. The voltage drop is the difference between the two batteries (KVL) and is independent of the wire size. Take that voltage and divide it by the wire resistance and you have the available current. That has to both charge the battery and supply the heater. Larger wire ( smaller gauge) will increase the total current until you hit the limit of the alternator. Every vehicle is different. And with so much electronics on current vehicles, I suspect the alternator is taxed. While others disagree, I have suggested that the prewired vehicles with small charging wires was intentional to limit that application.

My trailer battery is in parallel with my truck battery. Positive to positive, negative to negative. My alternator is also in parallel with these batteries. This is essentially one battery, and a parallel alternator in series with the heater. This interpretation also supports the idea that there is a wiring issue between the trailer and the tow vehicle.

It is possible that the additional load would reduce the life of the alternator. I had a 91 Pontiac Firefly. This had a 55 amp alternator. I put a 150 W, (12.5 amps) amplifier in it. By the time my third alternator failed, it occurred to me that maybe I was overloading it. If I do smoke my 95 amp alternator in my Ranger, I will purchase a 130 amp replacement.

[Raz]

Originally Posted by David Tilston

My trailer battery is in parallel with my truck battery. Positive to positive, negative to negative. This is essentially one battery, in series with the heater.

No sir. Read what I wrote and draw the circuit. The heater is in parallel with the trailer battery. And the wire resistance is between the battery terminals so they are not in parallel.

[gordon2]

Originally Posted by floyd

If you are buying new get a Danfoss.
...

You can't.
(Its now Secop)

So... If you are buying new get a 12 VDC / 120 VAC fridge with a Secop compressor.

Originally Posted by thrifty bill

For people that like to camp, I consider a dorm fridge to be the worst choice. ...

The good news is that a dorm fridge will work fine for the OP (Max) because instead of camping, he wants a camper to live in full time in his family's driveway. The bad news is he wants a camper to live in full time in his family's driveway.

[David Tilston]

Originally Posted by Raz

No sir. Read what I wrote and draw the circuit. The heater is in parallel with the trailer battery. And the wire resistance is between the battery terminals so they are not in parallel.

Yes, there is what should be, a very small resistance between the batteries. This resistance is comparable to the internal resistance of either battery, which I understand to be about 0.02 ohms. As per my previous calculation, there should not be more than 1.67 volts differnce between the batteies.

This does not explain a dead battery in the trailer, unless the battery in the tow vehicle is also dead, or at 1.67 volts. At which point, I would be conserned where nearly 1400 W of power is being consumed, assuming a load of 95A at 14.4 volts on my Ranger.

[floyd]

Originally Posted by gordon2

You can't.
(Its now Secop)

So... If you are buying new get a 12 VDC / 120 VAC fridge with a Secop compressor.



The good news is that a dorm fridge will work fine for the OP (Max) because instead of camping, he wants a camper to live in full time in his family's driveway. The bad news is he wants a camper to live in full time in his family's driveway.

I wasn't actually referring to a brand , but a type of compressor, but I'm sure you're right...

So buy a "quality built 12V compressor type refrigerator" like the old Danfoss or better. Dometic surely makes one.

[Raz]

Originally Posted by David Tilston

Yes, there is what should be, a very small resistance between the batteries. This resistance is comparable to the internal resistance of either battery, which I understand to be about 0.02 ohms. As per my previous calculation, there should not be more than 1.67 volts differnce between the batteies.

That's the charge line resistance. The internal battery resistance does not come into play because you are measuring beyond it. As I said, draw the circuit and apply your DC circuit analysis. If you have questions my friend, send me a PM and I will be more than happy to answer them. Oh for 5 minutes in room and a chalk board. Old school . Raz