lynneroy Posted August 9, 2015 Share Posted August 9, 2015 Probably a daft question, but if I have 90 watt solar panel could I run my fridge on 12 volt, at the moment I can only do this with the engine running, I would be happy if I could do it when parked up. Would I need an inverter fitting. Thanks for any advice Lynne ;-) Link to comment Share on other sites More sharing options...
lennyhb Posted August 9, 2015 Share Posted August 9, 2015 One word answer - No. I wouldn't even think about with less than about 300-400 A/H of batteries and 300-400 watts of Solar. An inverter would make the situation worse as you would be using at least 10% more power to cover the inverters inefficiency A Dometic fridge freezer uses about 3.2kw over 24hr that's 267 A/H, their figures so in the real world I would allow a bit more. Link to comment Share on other sites More sharing options...
Brian Kirby Posted August 9, 2015 Share Posted August 9, 2015 lynneroy - 2015-08-09 3:21 PM Probably a daft question, but if I have 90 watt solar panel could I run my fridge on 12 volt, at the moment I can only do this with the engine running, I would be happy if I could do it when parked up. Would I need an inverter fitting. Thanks for any advice Lynne ;-) Probably an equally daft question, Lynne, but why would you want to, when you can run it on gas (on which it would be more efficient)? Link to comment Share on other sites More sharing options...
spospe Posted August 10, 2015 Share Posted August 10, 2015 lynneroy - 2015-08-09 3:21 PM Probably a daft question, but if I have 90 watt solar panel could I run my fridge on 12 volt, at the moment I can only do this with the engine running, I would be happy if I could do it when parked up. Would I need an inverter fitting. Thanks for any advice Lynne ;-) If your fridge is a 12 volt compressor fridge, then yes you could run it off the solar panel. The panel would contribute to the power used by the fridge, but would not provide enough to meet the whole load (especially towards the start and end of the day). If you fridge is the usual 3 way device, then no way will a 90 watt (maximum) panel supply the needed 8 to 9 amps to run a 3 way fridge on 12 volts. With either fridge, you would not need an inverter. What is the point in converting 12 volt to 230 volt in order to run something which works on 12 volt? Link to comment Share on other sites More sharing options...
hallii Posted August 10, 2015 Share Posted August 10, 2015 My home fridge uses .569 KWh per day, and it's bigger and has a proper freezer. That means the M/H fridge is very inefficient. I have two 80w panels and in bright Spanish sunlight they might just run the fridge but that would leave nothing for charging the batteries etc. So not a good idea. I have worked out that on average my M/H fridge burns about 1 ltr of gas a day so about 60p a day. I can live with that. H Link to comment Share on other sites More sharing options...
lynneroy Posted August 11, 2015 Author Share Posted August 11, 2015 Thank you all for your replies, I am just deciding if refillable gas bottles are our only solution to travelling throughout Europe , we use a mixture of Aires and sites and currently have 2 7 kg Calor bottles, I am not sure how long they would last, we have hot water and heating. and would like to be go away for a couple of months at a time. Lynne x Link to comment Share on other sites More sharing options...
ChrisD Posted August 11, 2015 Share Posted August 11, 2015 Hi Lynne We travel Europe for up to six weeks using mostly aires and some campsites. My gas locker limits us to two 6Kg propane or two 7Kg Butane. We rely on the gas for fridge and hot water whilst on aires and have found that this combination is fine for 6 weeks with careful use. The fridge operates on 12V from the vehicle alternator whist on the move. We also have a 100w solar panel. The only weak link is my horrible leisure battery which is rapidly declining. It is true .... you get what you pay for and in this case I regret going cheap. Hope this helps Chris Link to comment Share on other sites More sharing options...
Tracker Posted August 11, 2015 Share Posted August 11, 2015 lynneroy - 2015-08-11 9:04 PM Thank you all for your replies, I am just deciding if refillable gas bottles are our only solution to travelling throughout Europe , we use a mixture of Aires and sites and currently have 2 7 kg Calor bottles, I am not sure how long they would last, we have hot water and heating. and would like to be go away for a couple of months at a time. Lynne x We don't use EHU at all and a 6kg Propane (same size different colour as 7kg Butane) lasts us between a worst case scenario of a week if it's quite chilly and we need the heating a lot in early Sring and Autumn and 2 weeks in summer with hot water every morning only plus fridge overnight and when we are not on the move. With one 6kg refillable bottle and one Calor back up just in case we can't find an LPG supplier, but we always have done so far, I top up the refillable whenever I judge it to be getting low. If you don't know your own rate of gas use reckon on roughly 1 kg per day in a chilly climate and half a kg a day in hot weather and it should be a reasonable guide to gas needs - that said we all have different consumption needs so that will vary so don't rely on a bottle lasting 6days or 12 days! You soon learn how long it lasts and it helps me to do that by keeping a record of how many litres I put in and how many days it lasts but with this set up I could tour indefinitely pretty much anywhere in Europe. You don't say how long you expect to go for but for 3 to 4 weeks as a cost effective solution you could carry a third bottle wrapped up and securely tucked away in a locker if you have the space. No doubt the experts will tell you why you should not do this but as long as the bottle is turned off tightly and the blanking cap tightly on I see no logical reason why not as we did that for many years and never ran out on three and four week trips. Link to comment Share on other sites More sharing options...
Guest Joe90 Posted August 11, 2015 Share Posted August 11, 2015 As above...............a refillable bottle, a no brainer if going over the water, or in the UK, best thing I ever did, a "Gasit" 11Kg branded bottle and remote filling kit for £162, plus a French filler adapter a couple of quid, and you'll never have the hassle associated with gas usage, will I run out, can I have the heating on, can I use the oven, blah blah blah....................plus the very real added bonus of paying peanuts for your gas which soon has you in pocket ;-) http://www.gasit.co.uk/index.php?_a=product&product_id=381 Link to comment Share on other sites More sharing options...
lennyhb Posted August 12, 2015 Share Posted August 12, 2015 hallii - 2015-08-10 10:05 AM So not a good idea. I have worked out that on average my M/H fridge burns about 1 ltr of gas a day so about 60p a day. I can live with that. H That's way above Dometic's spec, 150Lt 7 series or a 160Lt 8 series fridge freezer is quoted at 320g/24hr which is 0.627Lt. I thought our 8 series drunk a lot but it's nowhere near that much. Link to comment Share on other sites More sharing options...
Brian Kirby Posted August 12, 2015 Share Posted August 12, 2015 lynneroy - 2015-08-11 9:04 PM Thank you all for your replies, I am just deciding if refillable gas bottles are our only solution to travelling throughout Europe , we use a mixture of Aires and sites and currently have 2 7 kg Calor bottles, I am not sure how long they would last, we have hot water and heating. and would like to be go away for a couple of months at a time. Lynne x Then, as you have small gas cylinders, you will need to make provision for an increased gas supply to tide you over two months. You could carry a spare Calor (must be transported upright) but, as others have suggested, and especially as you want to tour widely in Europe, the most practical solution is likely to be one refillable cylinder with one Calor as back-up. An alternative, although more costly, would be two refillables. The extra cylinder should cost little more than one to install, although the cylinder itself obviously has to be paid for. But, you would then be completely free from the need to exchange Calor cylinders, and the associated inconvenience and costs of doing this. If you go this route I would suggest you do not get them installed to function as a single reservoir, but as two individual cylinders (each with its own contents gauge) so that you empty one before you start the next. That way, you know when you need to look for a top-up, and will have a full reserve while doing so. IMO, it would be worth starting a new string asking for information on the various refillable installations, as many people on here have these and each has its advantages/disadvantages. Link to comment Share on other sites More sharing options...
Archiesgrandad Posted August 12, 2015 Share Posted August 12, 2015 Can I go back to the 12 volt bit for a moment? My understanding is that with the 3 way fridges that most of us have, the 12 volt function is only intended to be used whilst the van is underway. The fridge is of the absorption type and is actually designed to run on gas, and to this end it operates through a thermostat and controls the temperature of the fridge to the level you indicate on the controls. They are generally pretty efficient if properly installed, and an 6 kilo bottle of gas lasts us weeks. The 240 volt function is intended to be used when connected to the mains, really just to save gas, and I imagine that it's origins are from it's use in caravans, which are normally parked up, and changing gas bottles can be an expensive chore, it is generally as effective and economic as the gas. Both of these functions are only intended to reduce the temperature of the fridge by about 15 degrees C below ambient, and this is probably acceptable for most of us for most of the time, but people do improve the performance of their fridges with fans and things, but unless you find a way of actually cooling the air to be below ambient you will not be able to reduce the temperature of your fridge beyond that 15 degrees. The 12 volt function is intended to provide a means of keeping the fridge cool when you can't run it on gas because the flame will be blown out as you drive along, and you can't connect to the mains, ''cos the wire's too short for anything over a 25 yard journey. On 12 volts it does not operate through a thermostat and just goes flat out all the time, also, for some reason it is my experience that it is no-where near as effective on 12 volts, and even over the longest, non stop, journeys it simply gets warmer through the day. On the vans that we have had the 12 volts are taken from the habitation batteries, but the clever bit somewhere in the system has a connection to the engine battery in order to sense the output of the alternator and only connect a12 volt supply to the fridge when the engine is running. On our Rimor Sailor that sensing connection was to the live side of the power feed to the windscreen wipers. I believe 12 volt compressor fridges, although their current consumption is greater, are thermostatically controlled,much better at getting rid of heat, and probably better insulated, so overall they work better and use less current. If I was rich and could afford an expensive new motorhome I would insist that it had a compressor fridge, even if I had to have the 3 way taken out and dumped on Ebay. AGD Link to comment Share on other sites More sharing options...
aandncaravan Posted August 12, 2015 Share Posted August 12, 2015 You can run a Fridge on Solar Power, we assisted someone finalise their system in making it automatic in that when Solar Power dropped below a certain amperage threshold it automatically switched over to Gas. It also had the ability to switch to Gas at a preset voltage, i.e when the batteries got down to 12.7v it again switched to Gas. The system cost a ridiculous amount of money to build. He had already invested over £2800 before he came to us, on a huge Solar Array and Battery bank. As most people know we are not fans of Solar Power and would have declined to do any work had he sought us out at the beginning. But as he had already spent so much and was so close to his goal we helped complete it. However, I could not stop myself asking why he had spent nearly £3000 creating a 'free energy' solution that saved him just £30 of Gas a season. Our work we did for free, but calculate out how long it will take him to recoup the rest of his investment? He just got carried away on the idea there was this free energy to be tapped, when as other people on here have already pointed out, the cost of Gas to run a fridge is tiny. Yes most people can go through a Gas bottle quite quickly, but that is normally from heating, Hot Water and Cooking. The Fridge itself is generally very efficient and a small consumer. Our advice, is don't even consider it. Link to comment Share on other sites More sharing options...
Brian Kirby Posted August 13, 2015 Share Posted August 13, 2015 Archiesgrandad - 2015-08-12 5:20 PM.................... ................ Both of these functions are only intended to reduce the temperature of the fridge by about 15 degrees C below ambient, and this is probably acceptable for most of us for most of the time, but people do improve the performance of their fridges with fans and things, but unless you find a way of actually cooling the air to be below ambient you will not be able to reduce the temperature of your fridge beyond that 15 degrees.......................AGD Not my experience or understanding Bill. On the fridges we have had since 2005, all have had thermostatic control on 240V, and the one we presently have includes a separate freezer that holds well below -20C on 240V. On 12V, AFAIK, none are thermostatically controlled. Absorption fridges are generally less efficient than compressor fridges, but are the only type that can run on gas or electricity. The 12V supply is only intended to work when the engine is running, although some manufacturers wire them otherwise. Strictly, the supply is not from either battery, as it is only enabled (when conventionally wired) via a relay that is switched from the vehicle alternator so, IMO, it is alternator fed. However, if touring widely for several months, the best way around the non-interchangeability of gas cylinders (except Comping Gaz) across national boundaries, and especially if limited to 6kg cylinders, the best overall remedy will be at least one refillable gas cylinder. Link to comment Share on other sites More sharing options...
Guest Joe90 Posted August 13, 2015 Share Posted August 13, 2015 Brian Kirby - 2015-08-13 12:17 PM Archiesgrandad - 2015-08-12 5:20 PM.................... ................ Both of these functions are only intended to reduce the temperature of the fridge by about 15 degrees C below ambient, and this is probably acceptable for most of us for most of the time, but people do improve the performance of their fridges with fans and things, but unless you find a way of actually cooling the air to be below ambient you will not be able to reduce the temperature of your fridge beyond that 15 degrees.......................AGD Not my experience or understanding Bill. On the fridges we have had since 2005, all have had thermostatic control on 240V, and the one we presently have includes a separate freezer that holds well below -20C on 240V. On 12V, AFAIK, none are thermostatically controlled. Absorption fridges are generally less efficient than compressor fridges, but are the only type that can run on gas or electricity. The 12V supply is only intended to work when the engine is running, although some manufacturers wire them otherwise. Strictly, the supply is not from either battery, as it is only enabled (when conventionally wired) via a relay that is switched from the vehicle alternator so, IMO, it is alternator fed. However, if touring widely for several months, the best way around the non-interchangeability of gas cylinders (except Comping Gaz) across national boundaries, and especially if limited to 6kg cylinders, the best overall remedy will be at least one refillable gas cylinder. Sounds like your now a convert to a refillable gas solution Brian, despite your previous protestations ;-) singing from the same hymn sheet as me, who'd have thought it. :D Link to comment Share on other sites More sharing options...
Brian Kirby Posted August 17, 2015 Share Posted August 17, 2015 Joe90 - 2015-08-13 12:27 PM.........................Sounds like your now a convert to a refillable gas solution Brian, despite your previous protestations ;-) singing from the same hymn sheet as me, who'd have thought it. :D Who indeed! :-) But I've never been "anti" refillables, any more than I'm "pro" exchange cylinders. Both do their jobs, and the choice is for the individual to make. There is an economic argument, and a convenience argument. Either could be the deciding factor. IMO there is no doubt that anyone who spends most of their time "off grid" in whichever country would be very well advised to look at refillables, as they will quickly recoup the initial cost through lower gas costs, and anyone who is unable to lift exchange cylinders, especially the 13kg jobs, around, has pretty well no alternative. I think at least one refillable is probably the best solution for anyone who has a gas locker that will only take 7kg cylinders, who also wants to make longer trips outside UK. Having said which, I'm perfectly happy with our Calor/Butagaz exchange cylinder choice, which has worked well for us over the past 10 years. So, when someone asks what to do about gas when abroad, I usually point out that possibility because most of the other advice is to go refillable. It is a workable alternative that suits us, so it just may suit others, and it may not have occurred to them. Link to comment Share on other sites More sharing options...
lennyhb Posted August 17, 2015 Share Posted August 17, 2015 Archiesgrandad - 2015-08-12 5:20 PM On 12 volts it does not operate through a thermostat and just goes flat out all the time, also, for some reason it is my experience that it is no-where near as effective on 12 volts, and even over the longest, non stop, journeys it simply gets warmer through the day. AGD All the newer fridges for about the last 10 years do have a thermostat on 12v and work much better these days on 12v, ours maintains both the fridge and freezer temperature without any problem. Link to comment Share on other sites More sharing options...
Guest Joe90 Posted August 17, 2015 Share Posted August 17, 2015 One thing I don't think anyone has mentioned, that it is usually easy to access the gas jet to enable servicing, but a failed 240 v, or 12 volt element usually involves taking the fridge out completely in many cases, a real pain in the proverbial :-( Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.