Refrigeration

[Captjimmy]

Having lived on a sail boat with its small hole in the countertop refrigerator, we were always envious when visiting trawlers and seeing what appeared to be gigantic stand alone refrigerators and freezers. Contemplating trawler life and would like to know the pros and cons of these large refrigerators for a couple living aboard and favoring the hook vs the dock.

Jim

[skipmac]

Main issue, will probably suck down a lot of power. Depending on the size and type stand alone you're looking at it could require running a generator 24/7.

[darylat8750]

Our very old Dominic quit working while we were in Mexico. Replacement would have been big bucks. So I now have a five year old apt. size (maybe 9 or 10 cu ft) $300+- with no automatic defrost. It almost fit the hole but I did need to raise the shelf above the opening.

House bank (also 5 years old and going strong) is eight 6 volt golf cart batteries. 5kw gen set and an inverter. I never have to run the gen more than 2 hours a day when anchored. If we go lightly on the other elec. loads and don't go into the refrigerator very often we sometimes get by with only an hour a day on the gen. I don't have big alternators on the main engines but if we move the boat every day we sometimes don't need the gen set at all. The newer refrigerators are more efficient than the one that I have. Ice makers, automatic defrosters and the through the door water things are energy hogs.

[Dockhead]

Remember that there are choices between the hole in the countertop type, and the full Sub Zero free standing type.

I have an Isotherm front-loading fridge. I don't know the exact size of it, but I think I have lived in apartments with smaller fridges. It has never seemed to small even with six people on board for extended cruises. And a separate freezer.

All efficiently water cooled so you don't need to run a genset 24/7.

I suffered through the hole-in-the-counter fridge with my last boat and would never go back. I'm sure you can find fridge happiness without necessarily going all the way to power-sucking domestic types.


Edit: The inside dimensions of my fridge are 60cm wide, 45cm deep, and 70cm high, which makes about 0.19 cubic meters or 190 liters or roughly 7 cubic feet.

[Dockhead]

Originally Posted by darylat8750

. . . Ice makers, automatic defrosters and the through the door water things are energy hogs.

And freezers!

My separate freezer, with separate compressor, seems to use about 5x the power of the fridge.

Nevertheless, I never switch it off. I could probably live, reluctantly, without the inventory of frozen food, but without ice??? Shudder!

I am guessing that small freezer compartments which are integral with a regular fridge are much more efficient than what I have.

[darylat8750]

Mine is a 2 door with the freezer on the top. I read someplace that the top freezer is more efficient than bottom freezers. I was careful to find a unit that has a large enough "radiator" on the back that a fan is not required and no energy is used pumping water around. Also my inverter is way bigger than needed for just the refrigerator. I think that a small inverter dedicated to the fridge may save a little energy if the big inverter didn't have to be in the standby or "idle" mode all the time. A big part of energy use is related to how long the door is open.

[lorenzo b]

We use two 7 cu/ft freezers from Sam's Club, $200 each, and run them 5 hrs a day off a Honda 2000 gas generator that supplies all the power we need for everything on board on the hook. It's all plug and play.
We carry a 20k Northernlights and diesel 250 bobcat Miller welding generator, 5 8D batteries, an inverter charger, all hard wired, and never use them. The little Honda trickle charges the batts and keeps them at 12.6v and that's where they live.
Been 5 years now on the hook and all is good.

[sailr69]

more important then type of unit is insulation, a small unit in a well insulated box will outperform a large unit in a standard insulated box

[a64pilot]

My Alder barbor cold machine when it's running pulls about 5 amps, or around 60W, My old Kenmore side by side house fridge pulls about 300w ( I used my inductive load meter as I was curious), I have red a new energy efficient one pulls half that, but they go through a defrost mode every ten hours to stay frost free and that has to pull a lot, how much I don't know,
And as it's been pointed out, the most important thing is insulation, I don't know the R value of a house fridge, but looking at how thin the walls are it can't be high, most important thing to them is to be able to advertise CuFt capacity, plus when you open the door, you have to let a lot of heat in, and since all coolers are really heat removers, all the heat removed by a house fridge would be dumped into the living space of the boat, adding a lot of heat

[Cheechako]

There are people on this forum using smallish apt size refrigerators with little additional power usage.

[skipmac]

No question that a mini fridge is reasonably efficient BUT the OP asked about "gigantic stand alone" refrigerators. Very different beast.

First I don't know of any 12V powered full size, front opening home type refrigerators so unless someone has a lead on one of these the OP will be limited to 120V AC powered units. That will take either a generator or a large battery bank with a largish invertor and a significant charging system or a combination of the two.

[Cheechako]

"First I don't know of any 12V powered full size, front opening home type refrigerators so unless someone has a lead on one of these the OP will be limited to 120V AC powered units."
Question: is it true that all compressors are 120v? I guess they used to be, and I thought that the newer Danfoss type were now actually 12v, but in another thread a while back I thought someone indicated they were still 120v motors..?

[Scott Berg]

Danfoss compressors use a 3phase AC compressor but not 120v single phase... The 12v frequency converter makes 3 ph AC and wipes out about 1/4 of the 40m band...

Check out Vitrifrigo's 8cf upright units, one has a bottom drawer for the freezer....

[skipmac]

Originally Posted by Cheechako

"First I don't know of any 12V powered full size, front opening home type refrigerators so unless someone has a lead on one of these the OP will be limited to 120V AC powered units."
Question: is it true that all compressors are 120v? I guess they used to be, and I thought that the newer Danfoss type were now actually 12v, but in another thread a while back I thought someone indicated they were still 120v motors..?

Have seen that question asked several times myself and have seen it answered both ways.

[meridian28]

We are using a Dometic RV propane/110v unit. Uses about a 20# tank every 3 weeks.