Fridges ....... your thoughts?

[SandJ]

This was posted on another site what are your thoughts?

FRIDGES

Most of us have the usual 3 way fridge in our vans but there is another option which is massively cheaper and more efficient.

A new 3 way fridge costs in the region of 1,000 pounds give or take, a normal domestic 240 volt compressor fridge varies but you can pick up a new one for as little as 90 pounds or 99 euro in my case.

If we consider for a start how we use the fridge

Mostly it’s not on at all because its winter and we are not using the van.

If we do use it we switch it on gas to start with while we get ready to go and it takes ages to cool down then we switch it to 12 volt while we are on passage which just about keeps it cool before we arrive at a campsite and plug it into the mains or switch back to gas.

If we use a 240 volt compressor fridge running off the inverter in the winter it’s just the same switched off.

Getting ready we switch it on and it cools down much more rapidly, on the move it stays switched on making ice and keeping everything really cool batteries are being charged with the vehicle alternator so no problem. Arriving at the campsite still stays switched on while you hook up or not as the case may be.

Power Usage

A normal 3 way fridge draws between 10 and 12 amps off the battery when its working on 12 volts this is because it uses a not very efficient heating element instead of a motor. A 240 volt fridge rated at 60 watts uses about 5 amps. Most campers have 2 x 100 amp batteries or 200 amps to play with so you can run your mains fridge for 40 hours without any charging at all. Most of us have solar panels so if its decent weather you can go on indefinitely with your 240 volt fridge. Of course you are going to use power running other items such as lights and water pump but not that much really.

Conclusion

Well my conclusion at any rate is that if your 3 way fridge goes wrong replace it with a compressor 240 volt mains fridge running off an inverter.

Should you not have a solar panel or inverter you can still save money on the cost of a new 3 way fridge by fitting an inverter and panel and still have 500 pounds change even a good quality inverter like a Victron 800 watts only costs 180 pounds. Solar panels are cheap enough get a 200 watt if you have the space but 140 watt will do the job too.

I did this to my Hymer Camp 64 and had no problems at all but did have ice for my G and T and nice cold beer.

 

[Odd-no-more]

This is worth a thought but they also do 12 volt compresser fridges. So no inverter needed.

 

[The Dudess]

This is worth a thought but they also do 12 volt compresser fridges. So no inverter needed.

Yes, but they're very expensive and small.

 

[funflair]

This was posted on another site what are your thoughts?

FRIDGES

Most of us have the usual 3 way fridge in our vans but there is another option which is massively cheaper and more efficient.

A new 3 way fridge costs in the region of 1,000 pounds give or take, a normal domestic 240 volt compressor fridge varies but you can pick up a new one for as little as 90 pounds or 99 euro in my case.

If we consider for a start how we use the fridge

Mostly it’s not on at all because its winter and we are not using the van.

If we do use it we switch it on gas to start with while we get ready to go and it takes ages to cool down then we switch it to 12 volt while we are on passage which just about keeps it cool before we arrive at a campsite and plug it into the mains or switch back to gas.

If we use a 240 volt compressor fridge running off the inverter in the winter it’s just the same switched off.

Getting ready we switch it on and it cools down much more rapidly, on the move it stays switched on making ice and keeping everything really cool batteries are being charged with the vehicle alternator so no problem. Arriving at the campsite still stays switched on while you hook up or not as the case may be.

Power Usage

A normal 3 way fridge draws between 10 and 12 amps off the battery when its working on 12 volts this is because it uses a not very efficient heating element instead of a motor. A 240 volt fridge rated at 60 watts uses about 5 amps. Most campers have 2 x 100 amp batteries or 200 amps to play with so you can run your mains fridge for 40 hours without any charging at all. Most of us have solar panels so if its decent weather you can go on indefinitely with your 240 volt fridge. Of course you are going to use power running other items such as lights and water pump but not that much really.

Conclusion

Well my conclusion at any rate is that if your 3 way fridge goes wrong replace it with a compressor 240 volt mains fridge running off an inverter.

Should you not have a solar panel or inverter you can still save money on the cost of a new 3 way fridge by fitting an inverter and panel and still have 500 pounds change even a good quality inverter like a Victron 800 watts only costs 180 pounds. Solar panels are cheap enough get a 200 watt if you have the space but 140 watt will do the job too.

I did this to my Hymer Camp 64 and had no problems at all but did have ice for my G and T and nice cold beer.

Can't argue with that other than 2x100ah batteries doesn't give you 200ah to play with, 100ah and you will basically have two flat batteries.

Martin

 

[SandJ]

Can't argue with that other than 2x100ah batteries doesn't give you 200ah to play with, 100ah and you will basically have two flat batteries.

Martin

So if you used the suggested method with solar the inverter would continue to drain batteries if poor sunlight. I am just curious to know if you can fit something that turns the inverter off and on dependent on batteries conditions, the fridge would be fine provided it was at ambient temperature and the door was not opened too often? My Dometic booklet shows a solar option of fridge freezer I would presume for one or more of the four models shown in the manual. I don't think mine has that option but not 100% sure as I don't know my model no.

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[Yorick]

My fridge killed my 2 batteries, both on 12v and 240v inverter. That's with solar here in Lanzarote.

 

[Wissel]

We have a 240v compressor fridge with an inverter and our setup uses less power than our last 12v (Vitrifrigo £800) compressor fridge.

Our fridge is a Inventor A++ rated model and we originally ran it off a 500VA Victron ECO inverter. Worked great, cost around £300 in total, gave us 240v on tap for other small appliances, and the best bit - it is silent (so much quieter than any other m/h fridge I've owned).

We have since swapped the inverter for a much larger Victron Eco model.

 

[shawn&emma]

My fridge killed my 2 batteries, both on 12v and 240v inverter. That's with solar here in Lanzarote.

Just interested as we're running a 240v through an inverter. Did your batteries die quickly or just didn't last as long as you'd have expected them to.

I did loads of research before doing our set up but always good to hear about actual usage/problems/issues etc.

We've only been using the 240v fridge in the van for a week now but even though we had three mainly wet and cloudy days in a row the batteries haven't dropped below 12.6v. Only being charged via solar.

Shawn

 

[HandyAndy]

It was bad to word it that his fridge killed his batteries without any further info.
Basically what he is saying is he didn't have enough solar to support the recharging of the batteries and or didn't have a large enough battery bank to supply the fridges usage overnight without deeply discharging them... THIS is what kills a battery, not the fridge.

 

[funflair]

So if you used the suggested method with solar the inverter would continue to drain batteries if poor sunlight. I am just curious to know if you can fit something that turns the inverter off and on dependent on batteries conditions, the fridge would be fine provided it was at ambient temperature and the door was not opened too often? My Dometic booklet shows a solar option of fridge freezer I would presume for one or more of the four models shown in the manual. I don't think mine has that option but not 100% sure as I don't know my model no.

A Dometic 3 way can run on solar via a solar regulator with AES S+ output, usually a Votronic but possibly Buttner as well as they are very similar. That doesn’t answer your question though really, I am sure there is something somewhere that will do what you want but it would really only be a sticking plaster on the original problem.

Martin

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[HandyAndy]

But anyway, if you want a comparison of some fridges and whether inverters are the way forward for you. Have a look at these two.

 

[EuroTrotters]

3 way fridges are not very efficient.

A lot of motorhome campers don’t have space for household refrigerators/freezers. Wheelarch intrusions and narrow spaces mean they have to use specially designed 3-way.

What I have done in our current motorhome is to keep the 3-way fridge. But build a small A energy freezer in above. Problem was, the compressor was rated @ 76w @ 240v.

So, I removed the inefficient Chinese compressor and fitted an Austrian eco version.

It runs off victron inverter with solar and 2 x us gel batteries without any problems.

Sand could be done to other small refrigeration appliances.

Yes, you can get 12v compressors. But the capacity is limited and they are expensive.

I’ll try to link my post

 

[EuroTrotters]

https://www.motorhomefun.co.uk/forum/threads/redundant-hymer-tv-cupboard-now-a-freezer.164292/

 

[tonyidle]

An A+ energy rated under-counter fridge I've just picked as an example and that has no freezer compartment uses, according to the specification, 113kW/hrs per year. That works out at 26Ah per 24 hours on 12v and assuming 100% inverter efficiency. There's a reason why 3 way absorption fridges have been used by campers since fridges were first installed in caravans. Three days under cloudy skies would see off most leisure battery installations so whether a conventional fridge would work for an individuals camping needs depends entirely on how the camping vehicle is used. If only in full Summer and with occasional EHU it's possible - just.

 

[Lenny HB]

A domestic fridge in a modern van would look a right bodge, & 2 days of cloud and you are but when working at least it would work like a fridge unlike Dometic fridges.

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[Ivory55]

Also depends on your camping. If it’s wild or on sites .

 

[Langtoftlad]

Of course there's the argument that on the days the fridge has to work hardest is because it's sunniest and thus your solar will be working at it's best

 

[Lenny HB]

A Dometic 3 way can run on solar via a solar regulator with AES S+ output, usually a Votronic but possibly Buttner as well as they are very similar.
Martin

I run mine that way, the Votronic regulator switches it in ½ hour blocks so as not to flatten the batteries and ensure they remain fully charged. On a good day it runs for a couple of hours on 12v.
I did have to fit a relay switched by mains on the regulator AES output as the stupid Dometic fridge has 12v Solar as the primary energy source. This means when on EHU the regulator sees the batteries as fully charged so gives an output on the AES terminal so the fridge switches to 12v. Like a lot of Motorhome manufacturers the designers at Dometic have never used one so don't have a clue how it needs to work.

 

[funflair]

I run mine that way, the Votronic regulator switches it in ½ hour blocks so as not to flatten the batteries and ensure they remain fully charged. On a good day it runs for a couple of hours on 12v.
I did have to fit a relay switched by mains on the regulator AES output as the stupid Dometic fridge has 12v Solar as the primary energy source. This means when on EHU the regulator sees the batteries as fully charged so gives an output on the AES terminal so the fridge switches to 12v. Like a lot of Motorhome manufacturers the designers at Dometic have never used one so don't have a clue how it needs to work.

I read that before Lenny but our older one prioritises 240v then gas then 12v if the alternator or the Votronic ask for it.

If you had used the D+ instead of S+ I would have thought it would be OK, you would just need a diode on the D+ lead.

Martin

 

[The Cricketers]

I have studied this question at some length, because although not exactly the same application, we have a beach hut with a 150 litre 12v compressor fridge running with 160 watts solar and 320ah battery pack, we also run lights, boiler fan, phone and laptop chargers etc
The system is 10 years old and we switch the fridge on in March and off in October and have never (touch wood) run out of energy
Some points to note - when it's not opened and in normal (less than 20c) temps the fridge uses about 15 amp.hr per day
However surprisingly when it's very sunny and the temp is above 25c, then the fridge uses up to 60amp.hr, because it is running almost continually to keep cool
So counter intuitively the sunnier it is the less able the system is to cope

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[Lenny HB]

I read that before Lenny but our older one prioritises 240v then gas then 12v if the alternator or the Votronic ask for it.

If you had used the D+ instead of S+ I would have thought it would be OK, you would just need a diode on the D+ lead.

Martin

I've fitted a relay now so all OK, rarely use EHU anyway.

 

[autorouter]

I think I'd want to know a few more details.

The fridge has a thermostat that switches the cooling on and off as required. That's why fridge power consumption is given in kWh per 24 hours, not just the wattage when the cooling is on. The 24 hour consumption depends on the insulation, outside temperature, how often the door is opened, and even what you put in the fridge. The manufacturer's figures are usually very 'optimistic' compare to normal usage.

Inverters vary in their efficiency for small loads. Many 2kw inverters have a no-load drain of around 2 amps, so that's 48 amp-hours per 24 hours just wasted. That's about the full output of a 100 watt solar panel on a long sunny day. A smaller dedicated 300 watt inverter would have much lower no-load drain.

Also part of the reason for using 3-way fridges is to avoid compressor noise, which can be annoying especially at night. Some fridges are better than others for this, but how do you find out without buying one?

 

[Ivory55]

I read on an Australian site that insulation was a big problem and they put extra insulation around the sides and top to help it.

 

[ianthebuilder]

I stay either on sites with hookups or at customers houses, again, with a hookup!

When my big fridge freezer packed up last year or whenever, I bought a standard domestic fridge, £80. As I’m always plugged in it’s a cheap option for me,, and while travelling, 3/4 hours unplugged doesn’t seem to be a drama!!

Downside is ,, this country is fine!! It I have got a genny, should I need it!

 

[EuroTrotters]

Some campers come with 12v fridge option over 3-way

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[tonyidle]

I have studied this question at some length, because although not exactly the same application, we have a beach hut with a 150 litre 12v compressor fridge running with 160 watts solar and 320ah battery pack, we also run lights, boiler fan, phone and laptop chargers etc
The system is 10 years old and we switch the fridge on in March and off in October and have never (touch wood) run out of energy
Some points to note - when it's not opened and in normal (less than 20c) temps the fridge uses about 15 amp.hr per day
However surprisingly when it's very sunny and the temp is above 25c, then the fridge uses up to 60amp.hr, because it is running almost continually to keep cool
So counter intuitively the sunnier it is the less able the system is to cope

If you have your panelled angled towards the South you're already 40% or so ahead of a similar panel mounted flat.