using a normal mains fridge via inverter

[mrbigglesworth]

When we had our self build, we had a compressor fridge, and it was fine in uk, but absolutely useless when travelling in southern Spain & France, despite have solar panel & 2 leisure batteries, and putting an outside vent - ended up more or less using as a cupboard - so in a nutshell I wouldn't recommend them. Another £360 went into the money pit.

-

Your right about the money pit. I'm surprised that you had more problems in France and Spain, them having more sun generally. Perhaps you needed another panel. I had 160 watts last year in France and it gave me 11 amps charge. I also have plenty of ventilation around the fridge and extra insulation on the door. I also fitted a 4" computer fan to cool the compressor as these can get very hot. If the weather was cr*p then the system did fall down and I would turn it down at night. They do need plenty of juice from the roof and batteries.

Mr B.

 

[Harmergeddon]

There's a very good reason why 12volt compressors fridges and 3-way fridges have been developed for caravans and mobile homes. They are compact, light,robust and efficient. As already said to get a 240volt compressor fridge to work well you will need expensive solar panels, a big invertor and a number of expensive, heavy leisure batteries all of which take up space and the weight will undoubtedly effect your fuel consumption. By the time you have saved money on the fridge you will have wasted it elsewhere.

 

[iampatman]

Yes, but one has to keep the beer and Chablis chilled, non?
Pat

 

[maxi77]

Compressor fridges, whether mains-powered domestic fridges fed via an inverter, or 12/24V DC type will require enough battery storage capacity to keep them running for whatever period of little or no sunlight you are happy to risk. A decent-sized fridge will consume between 60Ah and 100Ah a day so for a three-day backup you need to store 300Ah meaning a battery capacity of say 450Ah minimum.

Then you need solar panels or other means of charging the batteries to 100% asap once you do deplete them to that extent.

Easy enough to do if you own a BigRig, but not so easy on a typical smaller motorhome.

Compressor fridges do not use as much power as you suggest. This unit Waeco CR80 Motorhome Caravan Fridge should only max at 50 ah in hotter climes where pretty decent solar is available. Boats all tend to use compressor fridges and get by on 200 watts of solar and 300 ah of battery with many of them being off grid 365 days a year. It doesn't take that much gas to pay for a battery. 3 way fridges are hopelessly inefficient using 3 times the input power a compressor unit needs. In a selfbuild a custon compressor fridge with extra insulation could probably use up to 50% less power than the standard unit.

 

[Kiwi in Europe]

Why would you even think about this kind of complication? We have a Waeco 65ltr compressor fridge which draws 4.5amps. Even in 38° ambient it's never been on more than a 50% cycle. We only have a 120ah domestic battery with 180w of solar power and have never had a problem. OK, we don't do the UK with its permanent cloud, but 12v through an inverter, with all the inefficiency involved, seems to be taking a sledgehammer to crack a nut.

 

[Fazerloz]

We have a Waeco cr65 fridge . two 75ah batteries , 100w solar panel and don't have any trouble with flat batteries. As a fridge it is extremely good and keeps our beer and wine at a lovely temperature .

 

[maxi77]

Yes some boats may have generators or run engines, but boaties complain even more than campers about noise many moaning about wind generators. One of the reasons boats may have additional generating capacity is they in many cases use a lot more power for things light reverse osmosis watermakers fans winches, radio etc etc. Even so there are nany who operate with solar and battery capacity that can becarried on a motorhome. Yes gas can be a problem on a boat, you try getting a gas bottle several miles on a push bike, though I have seen long term cruisers with many 13kg bottles lashed on deck. Most boats do have gas so a gas fridge is quite possible and some do have them, but as we know they prefer the straight and level so a life on the ocean wave tends not to suit them.

 

[Tbear]

Sorry to digress but I have have now got an image in my head of someone cutting holes in the side of their hull for vents for their 3 way fridge. :wacko: How does that work???

 

[maxi77]

Sorry to digress but I have have now got an image in my head of someone cutting holes in the side of their hull for vents for their 3 way fridge. :wacko: How does that work???

One of the reasons very few are fitted, and also boats tend to have better ventilation when occupied. Also you cab have chimneys for your 3 way as we have in our LMC, There are so many ways of skinning a cat.

As for cutting holes the most efficient boat fridges and freezers use water cooling and have in water heat exchangers

 

[maxi77]

Most boaties use their bilge pumps to get rid of butane/propane in the bilges. I do remember though collecting Freon gas in big poly bags from the bilges of a nuclear submarine

 

[Harmergeddon]

It is. I have a waeco cr110 installed in my wagon. Good size, freezer compartment works well and its pretty quiet when running. I always keep it full when i am away so you have a good thermal mass in there so you don't lose all the cold air when you open up the door. During an average british summer trip away it's usually good for 5 days before i have to think about firing up the van to top up my leisure batteries. (450amp hours)