Fridge Freezer 220v or 12v?

[myocean]

Originally Posted by moseriw

Against some others: One should have a top-load fridge/freezer

Surely top load is nice. However, if your fridges compressor and isolation are by far less efficient than those from a 2020 best efficiency household fridge, you will still need more energy with the top-loader.

Originally Posted by moseriw

I doubt a 12V to 230V Pure Sine Wave Inverter (IMPORTANT!) to fridge will be as efficient as my unit.

Surely a fridge a needing 230V inverter has it's disadvantage and wastes some energy (may be 10%).
However, if your 12V fridges compressor and isolation are by far less efficient than a 2020 best efficiency 220V household fridge, you will still need more energy with the 12V unit.

All the marine equipment sellers are quite successful with their claims that their specialized, expensive marine fridges are the best. So, it is worth looking at the numbers.

[Jef & Marin, Netherlands]

Check this out:
https://www.cruisersforum.com/forums...an-205650.html


For 12V Vitrofrigo is a lot more efficient than Isotherm, in my experience. However a new A+++ European domestic frontopening freezer would in theory take half the power of our present 15 year old watercooled well isolated 100L Vitrofrigo deep freezer. Probably in reality power consumption would not really be half.

[Bill Seal]

Another to keep in mind is where the condensers are.
A lot of the dorm type fridges have the coils in the skin, so air circulation around them is critical.

[Cracassis]

Originally Posted by Tangarua

Hi guys

I'm after some advise on whether to kit my boat out with a 60L 12v Engel fridge/freezer which comes in at a whopping 12K South African Rands versus a normal little 220v domestic equivalent at 3K. Huge difference in price!! Should I not take the savings and beef up solar and the battery banks and inverter?Please advise.

Many thanks
PS. I should add I'm a live on board saddling up heading outta Dodge.

I have a catamaran for 17 years, where I lived for 14 years, I put a 270l 127V refrigerator with 3000W inverter is good until today (Google translate).

[Stu Jackson]

Originally Posted by Craig Cape Town

Hi.
Google Sailorchic34 12v fridge on cruisers forum. She uses a US 110v fridge powered from 12v through an pure sine inverter. Interesting stuff.

Here's the link to that:


https://www.cruisersforum.com/forums...ge-180007.html

[wingssail]

The 16,000 rand does not seem high for a refer usable on a boat. Our Dometic was $1200 USD plus the cost of building the box.

For us electrical efficiency is a primary consideration, use of 220v refer, via an inverter, may not be as efficient. A well insulated top loading box with a 12v air cooled compressor will run about 1 watt per liter of volume. Portable units are similar. A normal front loading refer could be similar but would often use more power due to their larger size and thin insulation.The total day's power consumption will depend on the duty cycle. (In the tropics the day's usage will be more than Alaska). We believe that the losses of using an inverter to supply AC are significant.

The second issue, a big one for us, is the fit of the refer into our boat. We can build-in a refer box in the galley efficiently using whatever space is there
but portable boxes and home units rarely fit in the galley of a small to moderate size cruising yacht.

Boats I've seen with portable units usually have them sitting somewhere in the cabin, on the sole, on a settee or out in the cockpit where feet normally go.

Home units rarely fit much better.

Bigger boats may be able to build them in.

In my view people put up with a lot of physical inconvenience or dubious efficiency because the initial investment is cheaper and they find justifications where they can.

[Cracassis]

Originally Posted by Cracassis

I have a catamaran for 17 years, where I lived for 14 years, I put a 270l 127V refrigerator with 3000W inverter is good until today (Google translate).

In addition: my bank of lead / acid batteries has 200A useful (nominal 920A) and 720W of solar panel (18% efficient).

[Dsanduril]

Originally Posted by wingssail

...For us electrical efficiency is a primary consideration, use of 220v refer, via an inverter, may not be as efficient...

Total electrical usage is why we switched to a 220V fridge and freezer. With the caveat that you have to be able to fit a rectangular box of fixed dimensions someplace.

We have a dedicated 375VA inverter that runs our refrigeration systems and stays on 24-7. Its idle load is 4-5W, so about 10Ah/day (maximum) of "wasted" energy. In running mode it is ~90% efficient and we use about 60Ah/day for refrigeration (less in the chilly north) , of that about another 5-8Ah/day is waste. For that, we end up with 150l of refrigeration space and 100l of freezer space and our freezer is at -18C. We switched from a built in custom unit that used more total energy, cost more, was harder to repair/replace, and didn't get down close to -18C for the amount of energy we were willing to spend.

That works out to a waste factor of nearly 20-25%, but in the end it still proved better for us overall. Everyone's math will be different, but for us using super-efficient household units worked out far better on the energy budget than using a "marine" system with all the extensive insulation.

[noelex 77]

Originally Posted by wingssail

The second issue, a big one for us, is the fit of the refer into our boat. We can build-in a refer box in the galley efficiently using whatever space is there
but portable boxes and home units rarely fit in the galley of a small to moderate size cruising yacht.

Boats I've seen with portable units usually have them sitting somewhere in the cabin, on the sole, on a settee or out in the cockpit where feet normally go.

This is not an inherent problem of portable fridge/freezers, but rather because the interior has been constructed for a built in marine fridge unit, which makes fitting something different difficult without major surgery.

It is possible to build in these portable fridge/freezers and achieve a good cosmetic result. Ideally you want to leave some flexibility so different brands, with slightly different sizes can be easily slotted in should replacement be needed. This is easily achieved with a little planning, but it is best done with an extensive galley refit, or new build, rather than simply trying to fit a portable unit in the space designed for a built in unit.

[smacksman]

The heat removed from the cooled box is transferred to the surrounding air by the condenser coil. If this is not supplied with fresh air rather than recirculated air in a locker, efficiency is reduced. Also if the ambient air is in the 90's then the compressor has to work harder and longer. I once fitted a Vetus product for a client where the evaperator coil was built in a skin fitting so 'water cooled'. It worked well even when the sea water was 80F+ in the tropics and even worked when hauled out and just air was entering the skin fitting.

[Joe Okros]

I think you should concentrate on getting "out of Dodge" and worry about your fridge when you are earning first world money. IMHO it won't be long before an Engel is going to cost you R50 000. From someone who left South Africa when the R/$ was R7/1$.

[s/v Jedi]

Originally Posted by Dsanduril

I understand the sentiment about 240V, but take the newer Liebherr 1760 as an example. 154l of refrigerated space that is rated to use 15Ah/day. It's really, really hard, and expensive, to find a marine refrigeration unit with that kind of energy usage.

The companion GP 1486 freezer provides 103l at -18C for about 25Ah/day. If you have room on the boat, for 40Ah/day you can have essentially household quantities of cold storage. All for less than USD1000. That's impossible in the marine refrigeration market.

Probably helps to keep these units running if the boat doesn't tip

Those figures are for when you keep them closed. Front opening units consumption in real world application is hugely more than too opening boxes. Think double or more.

[Dsanduril]

I've been living aboard full time for four years with an older model of the fridge (rated to use almost twice the energy of the latest model) and with the same freezer. Three years in the tropics and one in the cold north. I installed a wattmeter on the input side of the inverter because I really wanted to see how things perform.

IME, which is a sample of one, in real-world use, we used about 20% more than the rated values in the tropics, and currently use about that much less than rated values when the summer weather rarely gets above a balmy 20-22C.

I'd have to search the other threads I've posted in on this subject, but I have a link somewhere that compares test procedures with values found in real-world conditions. EU testing came out with about 60% using more in the real world, with the maximum excess about 17% above test values. That also means that 40% used equal or less than test values. Japanese and Oz/NZ came pretty close as well, US was a bit further afield.

The one big plus I see to a top-loader, especially in a freezer, is the holdover time. Our freezer is rated to maintain food frozen for 23 hours without power. They used to make the same model in a top-loader, that had a holdover time of something like 3 days. I lost that battle though, convenience won.

I've lived with top- and front-loaders, marine systems with evaporators and with holding plates, water and air cooled, engine driven and electric and I simply have never had lower energy usage than I do using the household units. And they're much more convenient.

That's a sample of one, I'm not going to tell anyone their solution is "wrong", just relate my own experience. Take it for what it's worth.

[Discovery 3]

Originally Posted by Tangarua

Hi guys

I'm after some advise on whether to kit my boat out with a 60L 12v Engel fridge/freezer which comes in at a whopping 12K South African Rands versus a normal little 220v domestic equivalent at 3K. Huge difference in price!! Should I not take the savings and beef up solar and the battery banks and inverter?Please advise.

Many thanks
PS. I should add I'm a live on board saddling up heading outta Dodge.

Hi Tangarua,I’ve got a fridge mate Evakool 60ltr 12v fridge freezer,can take the divider out and have all fridge or all freezer.Ive just finished running it for a solid 12 months without a hiccup and uses bugger all amps.I bought it for $1300. Australian dollars but worth every cent to me.It has a Danfoss compressor,bloody brilliant kit.I bought it from Australian direct if that helps.
It’s taken an absolute flogging,we would take it camping in 40’c Heat here in summer and still keeps the ice cream and iceblocks solid.