12v fridge or 230/240V ?

[lee b]

hiya all,i am looking at fridges for a narrowboat and after speaking to several people on the river near where i live i am wondering which fridge would be best...

a few people run a inverter to a 230/240v fridge and say this is a better option that a 12v fridge because a 12v fridge has its own built in inverter running all the while anyway and the fact that 12v fridges are 4 or £500 where you can buy a similar size 240v for 100-£120...

first of all i would like to here what live aboards mainly use and also if you use a 240v fridge would you use it on its own inverter as this would have to be on all the time...

one person i spoken to today said he uses a 1000w inverter to run his fridge and a few small items?

i was planning on putting a sterling 1600w inverter on my boat,other than the fan in my gas oven and the light/ignition i would only need the inverter for charging phones,a laptop and a charging a few tools up if needed...

 

if i decide to fit a 240v fridge would it use much more battery power by keeping the 1600w pure sine wave ''sterling'' inverter on 24/7...? cheers for your advice !

ps....it will be for continued cruising not for a electric marine hook up...also i am planning on 4 leisure batteries and also am planning on a 200w ''20amp ish'' solar panel set up...cheers again

[Paul C]

Unless you have a shoreline most of the time, I'd say go for the 12V fridge, even though it costs more. If you rely on an inverter + fridge, then 1) it consumes more power (power is expensive to generate on a narrowboat) and 2) that's 2 things to go wrong instead of one. If you have a need for an expensive PSW inverter (eg for other stuff) from one of the recognised good manufacturers (Sterling, Victron, Mastervolt) and don't mind the extra money, and plan on a lot of solar power (maybe for other uses in addition to the fridge, although the fridge is about half the power consumption typically), then it narrows the gap and either/or is okay.

[Ark Right]

Hi, I know it looks like a no brainer to pay £500 for a 12v fridge when you can get a 230v version for a fraction of that.

To clarify 12 volt fridges run off 12 volt batteries, there is no inverter involved and they are by far the most efficient way of producing cold.

In my experience the boats with the most problems with battery power run a 230v fridge through an inverter set up. Others will be along to reasons why you should buy a 230v unit but on the whole they will be wrong !

 

A 12 volt fridge will take approx 4 amps out of your batteries 50% of the time, i.e. on / off cycle.

I have recently found Sterling inverters taking nearly 4 amps out of the batteries at idle.

 

Planning to live aboard, its a no brainer not to buy the 12 volt fridge.

From your stated proposed 230v usage you could reduce the size of the inverter to off set the cost of the 12 v fridge

 

A

[Bill]

hiya all,i am looking at fridges for a narrowboat and after speaking to several people on the river near where i live i am wondering which fridge would be best...

a few people run a inverter to a 230/240v fridge and say this is a better option that a 12v fridge because a 12v fridge has its own built in inverter running all the while anyway and the fact that 12v fridges are 4 or £500 where you can buy a similar size 240v for 100-£120...

 

A 12v fridge does not have a built in inverter, it has a 12v compressor which runs about 1/3 of the time (cuts in and out as necessary to keep desired temperature). If you are not on mains hook-up a 12v fridge has got to be the better option provided you use suitable cabling to minimize voltage drop.

[Leo No2]

Moved from a 240v fridge to 12v fridge July-2011 and have never regretted the investment. Yes the capital outlay is greater but I don't 'have' to run the inverter to run the fridge.

[sueb]

A gas fridge prevents power problems and you dont have to switch it off at night

[Guest]

Must admit I like the idea of a gas fridge.

 

We run a 240V fridge off an inverter and I wouldn't go down that route again. 12V in future. Inverters are just too inefficient. I am not aware that 12V fridges have an inverter inside, but are a 12V compressor designed to start more softly than a 240V one (important when running off battery power.)

[mrsmelly]

A gas fridge prevents power problems and you dont have to switch it off at night

Hi

 

Sue is right gas fridges are best. As a second option mains fridges run through a good quality inverter are better than 12 volt. I am not guessing like some other posters my opinion comes from several years of mains fridges through inverter against several years of 12 volt kit. The vast majority of the years were without any shoreline.

 

Tim

[Guest]

Hi

 

Sue is right gas fridges are best. As a second option mains fridges run through a good quality inverter are better than 12 volt. I am not guessing like some other posters my opinion comes from several years of mains fridges through inverter against several years of 12 volt kit. The vast majority of the years were without any shoreline.

 

Tim

Interesting, Tim. How were your 12V fridges inferior? I always liked the 12V one on our previous boat. I am not talking about the 12V option on the 3 way ones which is dire, but a proper 12V unit.

[peterboat]

Hi, I went from 240 to 12 volt and as I am off grid and purely solar have noticed the difference my shoreline fridgefreezer uses less power than the 240 v item. Yes it was expensive but the no inverter fan running is a blessing

 

Peter

[Phil Ambrose]

A gas fridge prevents power problems and you dont have to switch it off at night

13 years living aboard with both a full size fridge and a full size freezer (both 12 volt) and never ever had to turn them off at night or any othertime.

My advice is use 12 volt for as much as you can because I have never seen the point of taking perfectly good 12 volt electricity and put it through a power hungry inverter to make 240 volts when 12 volt will do the job. Just to be clear I'm talking about a proper compressor fridge not one of these little 3 way absorption jobs. Usually compressor fridges use a Danfos compressor which are the bench mark models.

 

Phil

[Ange]

Oh lordy - we're still grappling with this dilemma!

 

Out of interest Sue (or anyone else who knows) how much gas does a gas fridge use?

 

Hi, I went from 240 to 12 volt and as I am off grid and purely solar have noticed the difference my shoreline fridgefreezer uses less power than the 240 v item. Yes it was expensive but the no inverter fan running is a blessing

Peter

When you say fridge/freezer are you talking about a tiny freezer box in the top corner or a decent sized freezer part? Does it keep ice cream frozen? Our 12v Shoreline has the tiny freezer bit but it can't keep ice cream at the right temperature - it's just good enough for lengthening the life of frozen stuff by stopping them from defrosting as quick as they would in the main fridge.

 

I'm very interested as hubby as assured me that even with solar we can't run a freezer.

 

I suspect we might be still dithering over the issue in a couple of years - too many conflicting opinions!

 

That's the boating world though innit (wouldn't have it any different)

Edited June 25, 2013 by Ange

[mrsmelly]

Interesting, Tim. How were your 12V fridges inferior? I always liked the 12V one on our previous boat. I am not talking about the 12V option on the 3 way ones which is dire, but a proper 12V unit.

Hi Stan

 

Must be honest I dont know why I didnt like them. They were not as economical as many people think though. The latest mains fridges use little if any more leccy than 12volt models, I bought a new one a couple of months ago and have checked its use. Also I am a Yorky and paying 500 quid for a poxy little fridge when in reality mains fridges are humungously cheaper grated a little.

My last boat was all mains and had the mastervolt inverter on 24/7 365 and I never switched the fridge off. We had only 3 by 110 amp hour batteries and were off grid for 3 years with that set up and never flattened my batteries. One thing though is the inverter choice makes a big difference I know I wouldnt try to live full time in that way with a cheapo stirling inverter they are not up to much at all.

 

Tim

[Pykebird]

Oh lordy - we're still grappling with this dilemma!

 

Out of interest Sue (or anyone else who knows) how much gas does a gas fridge use?

 

When you say fridge/freezer are you talking about a tiny freezer box in the top corner or a decent sized freezer part? Does it keep ice cream frozen? Our 12v Shoreline has the tiny freezer bit but it can't keep ice cream at the right temperature - it's just good enough for lengthening the life of frozen stuff by stopping them from defrosting as quick as they would in the main fridge.

 

I'm very interested as hubby as assured me that even with solar we can't run a freezer.

 

I suspect we might be still dithering over the issue in a couple of years - too many conflicting opinions!

 

That's the boating world though innit (wouldn't have it any different)

I managed to run both a 12v fridge and a 12v freezer for the last 3 years without shore power using just the engine, (2 hours in winter, less in summer) and 2x 180 w solar panels. So it can be done.

[lee b]

O well,i"ll flip a coin i think....i when i was told a 12v fridge has a inverter built in i thought that sounded like bol....s.... having had 12v fridge in caravans i do know a bit...still,are The 12v fridges on a boat as as small as a caravan fridge?as i recall we could fill ours with a bag of peas and a bottle of milk...

[BlueStringPudding]

Unless you have a shoreline most of the time, I'd say go for the 12V fridge, even though it costs more. If you rely on an inverter + fridge, then 1) it consumes more power (power is expensive to generate on a narrowboat) and 2) that's 2 things to go wrong instead of one. If you have a need for an expensive PSW inverter (eg for other stuff) from one of the recognised good manufacturers (Sterling, Victron, Mastervolt) and don't mind the extra money, and plan on a lot of solar power (maybe for other uses in addition to the fridge, although the fridge is about half the power consumption typically ), then it narrows the gap and either/or is okay.

Is it? Surely it depends on your other power needs. My fridge is very efficient but as I use little other power this time of year, it's probably 85% of my power consumption.

[Nightwatch]

We have a '12v' fridge, that we can also run via the inverter.

 

We had a recent problem with the fridge cutting in and out at very regular intervals and not staying on for more than a few seconds. This was on 12v. Via the inverter it was okay.

I pulled out the fridge to have a tamper and lo and behold it has what I can only describe as a small inverter fixed on top of the compressor. It's a Waeco (I'll spell that correctly later).

 

Now, having read this thread I have to ask the obvious question. Is it an inverter I saw or not.

 

Martyn. Edit to add. I suspect the alleged inverter is coming to the end of it natural.

Edited June 26, 2013 by Nightwatch

[BlueStringPudding]

O well,i"ll flip a coin i think....i when i was told a 12v fridge has a inverter built in i thought that sounded like bol....s.... having had 12v fridge in caravans i do know a bit...still,are The 12v fridges on a boat as as small as a caravan fridge? as i recall we could fill ours with a bag of peas and a bottle of milk...

If you buy a small one, yes. or you can buy a big one.

 

My 12v Isotherm fridge has 100 litre capacity and has a very effective freezer compartment, and importantly it has door storage like a normal household fridge. I can fit absolutely loads in it. I bought mine to fit in the specific hole in the galley, but there are bigger 12v fridges than mine. For example Isotherm also do 130litre one. Many household under the counter fridges are about 150litres, by comparison, so there's not a a great deal of difference. Although of course some household ones are bigger still.

Shoreline do a fridge with an attached but separate cabinet freezer on top of it, much like the upright combined ones you get for a house, if a little smaller. But perhaps that's what Ange has.

 

I did a lot of research into fridge options for the boat a couple of years ago when I bought mine. I wanted the most efficient fridge energy-wise, combined with the largest possible fridge that would fit in the space in the galley where the old fridge came out of. I also knew I wanted door storage and a freezer compartment. The best fridge I found, which combined all those things was the Isotherm I chose, but it was a very expensive make and I had to wait for it to be shipped in from Italy.

Edited June 26, 2013 by BlueStringPudding

[sueb]

New gas bottle every three weeks on average, but that was cooking as well. I would happily have paid twice as much for a silent reliable fridge

[Ally]

If you are mostly off hook up, I would say 12v fridge. We used a 230v one when mostly hooked up, but the power useage now we have a 12v fridge is hugely lowered. We rely heavily on solar ourselves, (having a useless alternator!!) so have really noticed the difference. An inverter itself uses power when switched on, so you can also lose that drain.

We are now completely 12v, even for charging lappys and phones etc...it's easy to do, and makes an incredible difference to the power useage.

12v shorelines or similar are expensive, but to my mind worth while.

[frangar]

We have a '12v' fridge, that we can also run via the inverter.

We had a recent problem with the fridge cutting in and out at very regular intervals and not staying on for more than a few seconds. This was on 12v. Via the inverter it was okay.

I pulled out the fridge to have a tamper and lo and behold it has what I can only describe as a small inverter fixed on top of the compressor. It's a Waeco (I'll spell that correctly later).

Now, having read this thread I have to ask the obvious question. Is it an inverter I saw or not.

Martyn. Edit to add. I suspect the alleged inverter is coming to the end of it natural.

What you saw I suspect was a transformer/rectifier/switch that drops the 240v ac to 24v dc. The 12v dc supply from the batteries is also wired into it.

 

This then means if 240v is available at the transformer it supplies the fridge with 24v dc.....if its not then a relay changes in the box and 12v dc from the boats batteries is used...

 

The compressor on the fridge can accept either 12v or 24v dc. No inverter is used on the fridge itself.

 

I think the unit is a Waeco MPS-35

 

http://www.waeco.com/en/3606_425.php?artOrigID=208&sprID=2

 

Cheers

 

Gareth

[Nightwatch]

Hi Gareth

By golly I think you're right.

 

Does look like an inverter doesn't it?

 

So, If I think this unit is coming to its end I could buy a new one and hey presto, it's fixed, or is t more complicated than that?

 

Thank you.

 

Martyn

[frangar]

Hi Martyn

 

I would first check the voltage at the DC input and output of the MPS-35 with the fridge motor running.....you may have fun doing this as you may need to get the multimeter probes into the connections on the fridge connector box without shorting anything out!

 

It may be that the MPS-35 is dropping the DC volts over its internal connections but my money would be on the DC supply to the unit from the batteries. Either the battery voltage is low or there is a bad connection somewhere. Have you checked the fuse board etc for surface corrosion?

 

Cheers

 

Gareth

[paul68]

This thread is very useful to me, I think I've made my mind up what type to get!

[Nightwatch]

Hi Martyn

I would first check the voltage at the DC input and output of the MPS-35 with the fridge motor running.....you may have fun doing this as you may need to get the multimeter probes into the connections on the fridge connector box without shorting anything out!

It may be that the MPS-35 is dropping the DC volts over its internal connections but my money would be on the DC supply to the unit from the batteries. Either the battery voltage is low or there is a bad connection somewhere. Have you checked the fuse board etc for surface corrosion?

Cheers

Gareth

Once again you may well be correct. This 'problem' normally occurs when the batteries are low. We need a long run in the boat to give the batteries a good charge. We moor at farm moorings with no power and run the engine to charge the batteries. Not long enough it seems. We visit the boat reasonably frequently but just 'go round the corner' for the weekend.

 

When the batteries are low and we switch to the inverter I would expect the inverter ,not, to work but it does and can go for hours when the DC supply gives the impression that it is nearly expired.

 

Thanks for your rock solid advice Gareth.

 

Martyn