paulstoke1975 Posted March 27, 2016 Report Share Posted March 27, 2016 im marina based and have enough time off work to take my boat out for 6 weeks over the 12 months, as i have just knackered my isotherm 12v fridge im looking for a replacement, i have the room for a small larder fridge so would i be better off buying a cheap 240v as im on shore power most of the time? Link to comment Share on other sites More sharing options...
OldGoat Posted March 27, 2016 Report Share Posted March 27, 2016 Ah, yes but - how do you propose to power it when you are out. Any fridge is power hungry and you'll need a reasonable inverter and battery bank, Get a good quality fridge - can be more efficient. What's your battery setup? Link to comment Share on other sites More sharing options...
Detling Posted March 27, 2016 Report Share Posted March 27, 2016 It depends on your cruising pattern when out. If you travel for several hours a day then battery charging is not an issue, if however you move for a few miles a day then you will not be running the engine long. A 12volt fridge will usually use 40-45 ish amp hours a day a 240 volt fridge about 50-60 ish amp hours a day it depends on how often the door is opened, what setting you have the fridge on and the cabin temperature. The extra is the inverter losses but the upside to that is you have 240 volts available all day for other uses. If you have above 300 watts solar the amount becomes irrelevant as you will get over 60 amp hours easily from the sun so you effectively have a solar fridge. Link to comment Share on other sites More sharing options...
b0atman Posted March 27, 2016 Report Share Posted March 27, 2016 a 240v fridge can be less amps if A++ or A+++ energy rated . Link to comment Share on other sites More sharing options...
rgreg Posted March 27, 2016 Report Share Posted March 27, 2016 My 12v fridge broke down and I "temporarily" replaced it with a 230v. That was three years ago and I've never bothered replacing the 12v as I can't notice any difference in consumption. Having said that, I've not measured it accurately. Link to comment Share on other sites More sharing options...
OldGoat Posted March 27, 2016 Report Share Posted March 27, 2016 rgreg, on 27 Mar 2016 - 5:09 PM, said:My 12v fridge broke down and I "temporarily" replaced it with a 230v. That was three years ago and I've never bothered replacing the 12v as I can't notice any difference in consumption. Having said that, I've not measured it accurately. It (often) depends on the 'quality' of the inverter. Some have quite a high standby power requirement and others - small. If your battery bank is large then that point becomes less of an issue. There aren't a lot of A++ or better A+++ units around. We 'need' a fridge freezer and Liebherr is the only make we could find that fits the space of our old LEC type unit. Link to comment Share on other sites More sharing options...
Paul C Posted March 27, 2016 Report Share Posted March 27, 2016 A++ and A+++ units are approaching the price of a 12V fridge. With the need for an inverter, you need to factor this in to both cost and power comparisons. Link to comment Share on other sites More sharing options...
paulstoke1975 Posted March 27, 2016 Author Report Share Posted March 27, 2016 I tend to travel 7-8 hrs when cursing and have a 3k inverter 1 starter 3 leisure batteries I've been offered a A rating fridge for free Link to comment Share on other sites More sharing options...
Quaysider Posted March 27, 2016 Report Share Posted March 27, 2016 I too would like a definitive answer for this question - we want a fridge freezer on-board Ellis and can't decide whether to spend nearly 600 quid on this http://12v-fridges.com/products/refrigerators/rir99dw4.html or save 400 and buy a 230v one... I'm tempted to try a 230 on first and if it works out too much of a strain to provide power for, flog it on and get the 12v anyway. Link to comment Share on other sites More sharing options...
peterboat Posted March 27, 2016 Report Share Posted March 27, 2016 popcorn time I had a 230volt fridge but because of two inverters that caught fire decided that 12 volt for me is better. If I was on shore power most of the time I would have saved the money and stayed with the 230 volt one that simple Link to comment Share on other sites More sharing options...
paulstoke1975 Posted March 27, 2016 Author Report Share Posted March 27, 2016 I'd be happy to switch fridge off altogether when cruising but obviously more convenient to have one Link to comment Share on other sites More sharing options...
Guest Posted March 27, 2016 Report Share Posted March 27, 2016 So hard to answer. We have a 240V fridge/freezer which we run off a 3 kw PSW Sterling inverter. Not actually too bad as the inverter is set to standby, so is consuming very little power until the fridge compressor kicks in. We hardly ever use shore power, and when out and about make enough power to satisfy the fridge. If I was on shore power for the vast majority of time, it would be a 240 fridge for me. Link to comment Share on other sites More sharing options...
ditchcrawler Posted March 27, 2016 Report Share Posted March 27, 2016 (edited) I tend to travel 7-8 hrs when cursing and have a 3k inverter 1 starter 3 leisure batteries I've been offered a A rating fridge for free Go for it and try it. I get by on 3 -4 hours running per day Edited March 27, 2016 by ditchcrawler Link to comment Share on other sites More sharing options...
Quaysider Posted March 27, 2016 Report Share Posted March 27, 2016 I know I probably appear "thick" here, but when trying to work out how much power they consume, I presume the simple method is taking the "quoted figure" for say the 12v one of 2.1a and multiplying it by 24 to get 50.4 ah daily When trying to work out the 230v one from the quoted from say here http://www.johnlewis.com/lec-t5039-fridge-freezer-a-energy-rating-50cm-wide/p1697499?colour=White of 194kwh per year - how do i turn it into ah? - after much buggerng about, I get it to about 55ah daily. but I can't for the life of me explain myself. Link to comment Share on other sites More sharing options...
DaveP Posted March 27, 2016 Report Share Posted March 27, 2016 I know I probably appear "thick" here, but when trying to work out how much power they consume, I presume the simple method is taking the "quoted figure" for say the 12v one of 2.1a and multiplying it by 24 to get 50.4 ah daily When trying to work out the 230v one from the quoted from say here http://www.johnlewis.com/lec-t5039-fridge-freezer-a-energy-rating-50cm-wide/p1697499?colour=White of 194kwh per year - how do i turn it into ah? - after much buggerng about, I get it to about 55ah daily. but I can't for the life of me explain myself. 194kWh/yr - 194,000 Wh/yr - /365 for Wh/day - /12 for Ah/day - 44.3 Ah/day? Link to comment Share on other sites More sharing options...
Paul C Posted March 27, 2016 Report Share Posted March 27, 2016 I know I probably appear "thick" here, but when trying to work out how much power they consume, I presume the simple method is taking the "quoted figure" for say the 12v one of 2.1a and multiplying it by 24 to get 50.4 ah daily When trying to work out the 230v one from the quoted from say here http://www.johnlewis.com/lec-t5039-fridge-freezer-a-energy-rating-50cm-wide/p1697499?colour=White of 194kwh per year - how do i turn it into ah? - after much buggerng about, I get it to about 55ah daily. but I can't for the life of me explain myself. On power usage, you need to allow for quiescent current and inverter efficiency too. On costs, you need to factor in the cost of a decent inverter. Remember, it will be on 24/7. Link to comment Share on other sites More sharing options...
Loafer Posted March 27, 2016 Report Share Posted March 27, 2016 Personally, I wouldnt have an inverter running at night while I'm asleep. Link to comment Share on other sites More sharing options...
WotEver Posted March 27, 2016 Report Share Posted March 27, 2016 194kWh/yr - 194,000 Wh/yr - /365 for Wh/day - /12 for Ah/day - 44.3 Ah/day? Generally in these equations we divide by 10 rather than 12 to allow for inverter inefficiencies. That results in more like 53Ah/day. Tony Link to comment Share on other sites More sharing options...
steve hayes Posted March 27, 2016 Report Share Posted March 27, 2016 Personally, I wouldnt have an inverter running at night while I'm asleep. We're 230v and turn the inverter off when we go to kip, the fridge is still pretty cool in the morning. Tends to be best with it well stocked as there's more mass to warm up. Now when we have the freezer on, that's a different matter. Link to comment Share on other sites More sharing options...
homer2911 Posted March 27, 2016 Report Share Posted March 27, 2016 Our 3kw Sterling inverter is too noisy to run at night. However, I believe that our 12v Shoreline fridge-freezer is rated at around 25 amp hours per day - more when the weather is stinking hot, obviously Link to comment Share on other sites More sharing options...
Keith M Posted March 27, 2016 Report Share Posted March 27, 2016 (edited) This so easy Having been installing both AC and DC fridges since 1984 The last time I installed a DC fridge was over 10 years With an Inverter inverter or inverter / charger from the likes of Mastervolt or Victron An with the correct type and size of battery bank AC is the way to go Keith Edited March 27, 2016 by Keith M Link to comment Share on other sites More sharing options...
Bro Posted March 29, 2016 Report Share Posted March 29, 2016 It is quite possible to wire and control an AC freezer to run as a fridge (better insulation) and have the inverter cut-in on demand only (thus limiting inverter loss). Bear in mind that when running the engine (travelling) inverter loss will be insignificant. I would however switch off the inverter when asleep or away from the boat and also ensure a good fire extinguisher is always in the vicinity. Link to comment Share on other sites More sharing options...
Alan de Enfield Posted March 29, 2016 Report Share Posted March 29, 2016 Replaced our fridge and freeezer last year. It originally had an Electrolux 3-way (without the gas or 220v connected) and was horrendously 'thirsty' on electricity, running continously. The 'freezer' was a big 'carry-chest' freezer which again was 3-way, with only the 12v connected - from memory it was something like 10amps - continuous - 240Ah per day. I am guessing that is why the boat was fitted with 6x 230Ah batteries. Sold the fridge on ebay for 90 pounds. Sold the freezer on ebay for 240 pounds Replaced them with a 12v Waeco fridge (which I managed to get the VAT 'knocked off') for 458 pounds and a 220v freezer from Argos for 89 pounds. Both fridge and freezer use about 45-50 Ah per day (100 total) so its an all round win-win. Should I 'lose' the 220v for any reason I still have the small ice-box in the fridge. It works for me. Link to comment Share on other sites More sharing options...
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