Compressor -v- 3 way fridge

Deadsfo

Guest

I will eventually require a fridge ,not quite ready for one yet, my question is what is the main advantage between the compressor and 3-way.
It seems to me that the compressor fridges are very expensive and you dont see as many second hand as you do the 3-way and only having 12/24 volt choice limits you to having a self sufficient electric system whereas you can run the 3-way on gas if there is no EHU and save your batteries for lights etc.On the other hand cutting great big holes in the side of my van for grilles and exhausts does'nt thrill me!!
I have no knowledge on the efficiency comparison between the two, is this a factor? ,another thing are the compressor fridges smaller for the same litres of internal space. Which is the noisiest, which would use the most power for the same litre fridge.
And generally any pertinent points anyone can add
 
If you went for a compressor you would have to factor in the cost of solar panels and controller plus a good sized battery bank.
A 3 way fridge plus the cost of a gas tank/bottles. (you will probably have gas for cooking?) It also depends on where you intend to use the van, here in the UK where the sun only shines on tv ;). or in mainland Europe where you have more sun. I went for a 3 way fridge and a 20 litre under slung gas tank so we are able to go away in winter without hook up.
 
There are advantages and disadvantages of both designs, the choice probably depends more on how you intend to use the van - if you travel every day and can recharge the batteries then the compressor fridges are more efficient, if you want to sit for a few days then the 3 way fridge is the way to go by running it on gas.

With all things cold, the installation of the fridge is really important, follow the fitting instructions to the letter and you will have a good efficient unit, scrimp and expect to have rotten food every day. Even in temperate climates its best to fit the fridge to the tropical standard - baffles, fans, thicker cabinet, good ventilation.
 
If you are planning to be on hook-up most of the time then a compressor fridge like a 'Waeco' is the way to go. 3-way fridges such as Dometic are really the only option if you tend to wild it, but they are hopelessly inadequate in temperatures much over 20C. I have seen temps INSIDE a 3-way fridge of 15C with an external temp of 32C. AND 3-way fridges need to be on a level surface - I think their tolerance level is about 6 degrees or something like that - anything over that and they don't work at all.
 
El Veterano said:
If you are planning to be on hook-up most of the time then a compressor fridge like a 'Waeco' is the way to go. 3-way fridges such as Dometic are really the only option if you tend to wild it, but they are hopelessly inadequate in temperatures much over 20C. I have seen temps INSIDE a 3-way fridge of 15C with an external temp of 32C. AND 3-way fridges need to be on a level surface - I think their tolerance level is about 6 degrees or something like that - anything over that and they don't work at all.
Click to expand...

- and this is why compressor fridges are better than the 3 way fridge freezer rubbish thing we've got :(
 
I bought a wireless thermometer and placed the receiver in the fridge.
We went to Italy in summer. 15deg c INSIDE the fridge and more if you had to open the fridge more than 2 times a day. No matter if it ran on Gas or EHU.
We had to move temperature sensitive food inside the freezer during the day. The freezer was just ok for this during the day (if you kept the door shut). If we forgot to take the food out in the evening, it was frozen in the morning.

I have one of these outside strong fans which draws air out from behind the fridge through the top vent.
Despite making a lot of noise (would wake you up in the night), it didn't have an effect on the temperature.
If ambient is 35deg C, you are only shifting hot air around.

A 3 way fridge will only cool to 20deg C less than outside temperature. Something I also found quite annoying is the crude temperature control on these fridges. One has constantly to keep an eye on the setting between day and night time. If you forget to turn the fridge down over night (because you had it on full during the day and still not having it cold enough) because the ambient temperature is dropping below 20deg C ish, you stuff can be frozen in the morning.

I can't fit a compressor fridge because it will make you more or less dependent on 240V or a LARGE battery system.
My ideal setup would be to have both. I am looking to buy a compressor mobile box which I can use for temperature critical food and keep the 3 way running on gas while we are on the move or away from EHU.

I also found that the 3 Way fridge is NOT so critical on lean angles as claimed. Mine was working fine with two wheels parked on a high curb over night.

Stick one of these in the fridge, you will be surprised how poor a 3 way fridge performs Wireless Thermometer clock with outdoor temperature | eBay

I have learned a great deal about using the fridge from the forums:
-- have some freezer packs in the freezer and move them to the bottom of the fridge during daytime.
-- or freeze up water bottles instead of freezer packs. Helps the fridge to cool while they thaw and you have some cold water to drink at the end of the day :)
-- have freezer packs to support the cooling when you switch power source of the fridge. I.E. when going to 12V from Gas. It will take a while for the 12V element to take over from the Gas.
-- Don't open the door all the time!
-- Don't load too much stuff for cooling at one time. The little fridge is not as powerful as you think.

But all taken into consideration, I would not count on a 3Way fridge if I would stay longer periods in the Motorhome in a "real" summer environment. Staying in the UK isn't such a problem but even UK summrs are getting hotter and hotter......
 
We've got a domestic 3 way fridge & I can't even work out which way to turn the dial to make it colder. :cry:
 
I would strongly suspect inadequate ventilation if a 3 way fridge isn't working properly in hot weather. Our (internally vented, so no external vents just a small flue in the side of the van) RM123 performed flawlessly on both gas and mains last year in 40c temperatures in Croatia.

I see the compressor vs 3 way choice as dependent on how you want to use the van.

I went 3-way rather than 12v Waeco type specifically because I want to be able to run the fridge for a week or more on gas when we don't have the luxury of a hookup. The 3-ways are more complicated to install but in my opinion provide more flexibility.

Granted with any front loading fridge all the cool air falls out every time you open the door so it makes sense not to open and close it constantly.
 
A decent tropical-rated three way (if you can find one in Europe), PROPERLY installed according to manufacturers requirements (assuming they are technically competent to produce proper instructions and you can find someone smart enough to follow them) IS the cheapest and most convenient option for the vast majority of motorhomers, especially if they already have a propane installation installed and travel where propane is easily obtained.

If you are running an expedition rig and want all the goodies to give you a nice lifestyle away from civilisation, then covering the roof with solar panels and installing adequate battery storage and going all-electic and diesel will probably/possibly be better.
However, these owners will often install diesel heating and cooking and think they are the antspants - until they get up above 3500 metres where I am now and find their diesel systems wont fire up and are just useless ballast. Then they realise that a bit of propane would make life a lot more bearable on the Bolivian salt lake when it is -25C in the shade and the wind is blowing force 5..

I've got both, and find that while compressor fridges certainly do have advantages in certain situations - eg


IMG_3480.JPG

they do require very large solar systems to avoid having to worry if your system will keep them running during inclement weather or if you are camped under the shade of the proverbial spreading oak tree. Decent three ways are switch on and forget them.
 
:bow: :bow: Oohh, 'ark at 'im Matron. How patronising can you be in one post, and with more than a dash of supercilious oneupmanship to boot.
 
shaunr68 said:
I would strongly suspect inadequate ventilation if a 3 way fridge isn't working properly in hot weather. Our (internally vented, so no external vents just a small flue in the side of the van) RM123 performed flawlessly on both gas and mains last year in 40c temperatures in Croatia.

I see the compressor vs 3 way choice as dependent on how you want to use the van.

I went 3-way rather than 12v Waeco type specifically because I want to be able to run the fridge for a week or more on gas when we don't have the luxury of a hookup. The 3-ways are more complicated to install but in my opinion provide more flexibility.

Granted with any front loading fridge all the cool air falls out every time you open the door so it makes sense not to open and close it constantly.
Click to expand...

Well, if you read through the manufacturers spec sheet they will tell you -20degC from ambient. So you either have a different spec fridge, or you didn't actually measure the temperatur in your fridge. Or do you have the habitation area air conditioned so you fridge won't vent to the 40deg C outside?
 
Teutone said:
Well, if you read through the manufacturers spec sheet they will tell you -20degC from ambient. So you either have a different spec fridge, or you didn't actually measure the temperatur in your fridge. Or do you have the habitation area air conditioned so you fridge won't vent to the 40deg C outside?
Click to expand...
The manual for mine states when properly installed it will refrigerate at ambient temperatures up to 32c with some measure of cooling up to 35c.

http://www.club80-90.co.uk/pages/downloads/tech/ElectroluxRM122.pdf

My experience, with no air conditioning in the vehicle, on a blazing hot summer day in Southern Europe with temperatures in excess of those above, and the fridge being internally vented only, would suggest that these figures are conservative and it will operate satisfactorarily well outside of the claimed range.

It helps a lot if you fill the fridge with goods that are already cool so all it has to do is keep the contents cold. Of course this applies to compressor fridges too, in fact more so if you don't want flat batteries in a matter of hours.

Cheers
 
I use a compressor fridge and only wildcamp so no hook up.Works fine all year round.The only downside was the purchase price!
 
My Wellhouse campervan came with a compressor fridge. I have solar panels and the leisure battery is only 87amps. The fridge has a freezer compartment which works as expected and ice-cream is rock hard. I have it on electric hookup at night at home or in a campsite, but if wilding just turn it off at night. It stays cold enough until the engine is running the following morning and doesn't down the battery excessively when on during normal driving. Because it is a compressor fridge I don't need to use ramps and a bit off level doesn't matter.
 
3 way fridges have a limited cooling capacity and do tend to struggle in high ambient temperatures though you can help with fan assistance in the cooling vents. Most boats use compressor fridges because the 3 way type are unhappy when tipped and oldder models did not have flame failure devices so were seen as an explosion risk, you cannot drain lpg out of a boat the way it will drain out of a van. Boat compressor fridges are quite efficient these days and have devices like 'cold plate' to store 'cold' made when the engine is running or other forms of charging are available. Boaties also go for more installed battery (over 500 AH is not uncommon for liveaboards) and make use of a lot of solar 200+ watts and wind and/or water generators. My last boat fridge would use about 15-20 AH a day, and could act as a freezer, and run on mains if available
 
I fitted a waeco compressor fridge in my last self build and had a small solar panel and 2x110amp batteries never had a problem with power in 10yrs of wild camping. Except once while in france on aires because it was warm and i was not moving every day my batteries got low so had to goto a site on ehu for a few days to recharge. My current van is a coachbuilt and i was going to get another 12v fridge but so far the 3way has been great apart from its very small inside due to the wheel arch bit at the back.

Mike
 
Absorption fridges use a very different process to compressor fridges and are quite simply not as efficient. On electric power they use more than 6 times the power that a compressor fridge uses yet can only cool to some 25 degrees below ambient. Note the ambient is the ambient at the heat exchanger which may well be more than in the cabin. Many compressor units can be set to freeze never mind fridge temperatures and can be used just like a home freezer. Interestingly thermo-electric fridges are actually more efficient electrically than absorption fridges despite their reputations. Of course neither compressor or thermo-electric fridges will run on gas, but with the current improvement in both efficiency and cost of solar power perhaps this benefit is coming to the end of it's natural life.

And yes the fans do work, as they replace hot air round the heat exchanger with cooler air, mind you that does make the system even more power hungry even if it does improve the hot weather performance
 
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