How much fridge freezer do I need?

[GreenHeaven]

The usable capacity of my new design with 4in XPS R5 material on all sides and top, 6in on bottom comes to a paltry 3.4 cu ft
If I split that into a 1 cu ft freezer and fridge combo, I think the dometic 50 unit should be ok to cool both, but this is a tiny fridge


The main problem is the sloping side of the boat. The fridge interior becomes a stair step with room for 2 milk bottles width at the bottom level


I only have .9m of galley boat length to work with, but I could extend the fridge out into the galley standing room another 4 inches or so. It will just look ugly.

We want to do a crossing of 6-10 days, but mostly we go ashore a few times a week cruising.

If we catch fish we need to freeze them and need more freezer

Ideally I should get a separate freezer, but marine ones are so expensive. Household ones wont fit through the companionway

I will construct entirely new built in fridge box. But the mre I work on the design, the less I like the size restrictions

[kmacdonald]

Use three inches of insulation instead of 4.

[Scubaseas]

Vacuum panels are thin and high R value. Rparts.com sold me some 20+ years ago that are still fine. Cover with 1" foam board and then maybe stainless or fiberglass.

BougeRV . YETI and others make decent size portable units that might work for you. Especially if you turn them on as you catch fish.

[JPA Cate]

Originally Posted by GreenHeaven

The usable capacity of my new design with 4in XPS R5 material on all sides and top, 6in on bottom comes to a paltry 3.4 cu ft
If I split that into a 1 cu ft freezer and fridge combo, I think the dometic 50 unit should be ok to cool both, but this is a tiny fridge


The main problem is the sloping side of the boat. The fridge interior becomes a stair step with room for 2 milk bottles width at the bottom level


I only have .9m of galley boat length to work with, but I could extend the fridge out into the galley standing room another 4 inches or so. It will just look ugly.

We want to do a crossing of 6-10 days, but mostly we go ashore a few times a week cruising.

If we catch fish we need to freeze them and need more freezer

Ideally I should get a separate freezer, but marine ones are so expensive. Household ones wont fit through the companionway

I will construct entirely new built in fridge box. But the mre I work on the design, the less I like the size restrictions

Hi, GreenHeaven,

I certainly understand the desire to be able to freeze the fish you can't eat in 3 days! Our first year cruising was with no refrigeration except blocks of ice.
We learned to pickle fish. (Thanks Greg and Anne). All small boats have limited capacity. We also learned to take only half a fish, and give the remainder to someone else. Finally, some was discarded, and something else ate it.

When you are near native villages, the chief really appreciates a gift of fresh fish, and often fish head soup is a delicacy to them. They don't mind that it is not a whole fish: they are glad of the "windfall."

Some people use car fridges, to expand their cold storage, using that one for the things that don't have to be seriously cold, but last better well cooled; and you can make closed cell foam covers for them to protect them from the warm air, which helps with the electricity consumption. Under 40 feet, there's unlikely to be a good place to put it.

We learned to live with a simple fridge, no freezer, but it is one's attitudes that need to change to accommodate what one in fact has and not worry about it.

We did have a freezer for a while, and I loved having ice cubes for beverages. The unfortunate truth is that it takes (in our terms) a LOT of electricity to change water from liquid to ice, and we didn't have the space for more solar panels. There has been life after no solid water.

3.4 cu ft. of very cold, w/o freezing, would be a pretty good deal, actually. There are many things that people tend to refrigerate that do not normally require it! You'll learn.

Ann

[s/v Jedi]

We have 200 liters of freezer space and 100 liters of refrigeration and can store everything for 9 months cruising without any additional provisioning.

So just take ratio for the duration you need and it should work out

[Bowdrie]

Originally Posted by GreenHeaven

We want to do a crossing of 6-10 days, but mostly we go ashore a few times a week cruising.
If we catch fish we need to freeze them and need more freezer

If you mostly "go ashore a few times a week", it could be argued that you really don't even need a freezer,
Freezers use a LOT of energy, and more so if trying to freeze fish.
Catch a fish, eat what you want, toss the rest, catch another.
With careful packing you can get ~30lbs of beef in 1cuft.
Twenty-five or so lbs. of meat should last a lot more than 6>10 days for 2 people.
Insulation is king, don't short yourself.

[GreenHeaven]

Originally Posted by kmacdonald

Use three inches of insulation instead of 4.

While I appreciate the comment, im not sure of the engineering behind it.
Most of the threads I read say minimum 4in. The side of the boat is exposed to sun all day long. the last SS tank was a disaster

the compressor could run both if the insulation is sufficient, but in the SS box it was running 24/7

[s/v Jedi]

Originally Posted by GreenHeaven

While I appreciate the comment, im not sure of the engineering behind it.
Most of the threads I read say minimum 4in. The side of the boat is exposed to sun all day long. the last SS tank was a disaster

the compressor could run both if the insulation is sufficient, but in the SS box it was running 24/7

If your hull is solid (not cored) fiberglass and the hull is part of the box, then you will have trouble with 4” insulation as well… just a bit less trouble than with 3” insulation.

The best thing you can do for the food is buy a Snomaster Expedition series “portable” fridge/freezer and put it under the salon table, away from the hull and deck. These only have 2.76” insulation, a stainless steel exterior and will do everything you wish for at high efficiency.

The only way I beat these was with custom boxes on the centerline of the boat, under the pilothouse floor so no deck above and with a minimum of 6” insulation on the sides, 4” at the top opening lid and 8” on the bottom, with Frigoboat keel-cooled compressors. That system (I built it) worked very well for 15 years, after which the refrigerant couplings started leaking and I found moisture in the insulation again.
That whole build, all the effort and expense that went into it, wasn’t worth it and instead of rebuilding again, I went for the Snomaster boxes. If these are end of life, I simply pop in a new one. I wonder how the lifespan will turn out to be. For the past 3.5 years they have performed great. The big competitor is Engel but those aren’t stainless steel.

[GreenHeaven]

Originally Posted by Bowdrie

If you mostly "go ashore a few times a week", it could be argued that you really don't even need a freezer,
Freezers use a LOT of energy, and more so if trying to freeze fish.
Catch a fish, eat what you want, toss the rest, catch another.
With careful packing you can get ~30lbs of beef in 1cuft.
Twenty-five or so lbs. of meat should last a lot more than 6>10 days for 2 people.
Insulation is king, don't short yourself.

yes exactly. dont have it now.
My idea is to amke the freezer section a removable baffle that sections off 1/3 of the box if I need it. If I dont then its just fridge

[GreenHeaven]

Originally Posted by GreenHeaven

yes exactly. dont have it now.
My idea is to amke the freezer section a removable baffle that sections off 1/3 of the box if I need it. If I dont then its just fridge

Old 90s boat. Solid Hull inch thick.
by trouble, I think you mean that it will heat up with the sun. yes it does. old fridge was useless.
I was thinking of leaving a 1cm air gap between insulation and hull to permit air convection from bilge up to cool the hull, and NOT let the insulation touch the hull. What do you think?

high end 12v freezers are unavailable here and far beyond my budget )


200 litres of freezer space is huge! how big is your boat?
where is it all?
I have a 200l fresh water tank!!

I also have another fresh bigger fresh water tank I do not use thanks to the water maker, but it is structural and uses the hull as part of the tank. Cutting into it from the top would ba huge undertaking

[davil]

"We want to do a crossing of 6-10 days"

Have being cruising since May, did not want to replace my kaput refrigerator.
Purchased a freestanding
F40C4TMP Portable Refrigerator 20 Quart 12 Volt Freezer (-8℉~50℉) 18L Car Fridge with Compressor 110-240V AC for Camping, Truck, RV, Travel, Boat and Home Use

Paid $ 229

Carry precooked zip bags with stews, stirfry, etc.
keep temp at freezing temp (30 to 31 degrees), bags lasted one month since I cooked a lot at home before leaving.

now underway, cook every other week and keeping the bags fine.


Either anchor or mooring, no outside power, I
run a 400 w solar panels and is ok.

There are higher quality units like dometic, for my needs the cheapo is fine.

[kmacdonald]

Originally Posted by GreenHeaven

While I appreciate the comment, im not sure of the engineering behind it.
Most of the threads I read say minimum 4in. The side of the boat is exposed to sun all day long. the last SS tank was a disaster

the compressor could run both if the insulation is sufficient, but in the SS box it was running 24/7

Three inches is fine for a frig. 4 is better for a freezer. use 4 or 5 inches on the bottom. Portable frig/freezers have less than 2 inches. The dimensions make a difference also. The closer to square the better. You don't have much discretion in dimensions though.

[JPA Cate]

You could use the spray-in closed cell foam between the topsides and the outer part of your fridge. I am not sure the convection will work the way you hope, because hot air rises, and how will it get out the top to pull in cooler air?

Jedi's boat is 64 ft. It is right there at his avatar. You could fill in more information for yours. It will be editable in your CP. "Gender: Male" doesn't say much about you, at all. A general idea of your location and the boat help people give answers to your questions.



Ann

[s/v Jedi]

Originally Posted by GreenHeaven

Old 90s boat. Solid Hull inch thick.
by trouble, I think you mean that it will heat up with the sun. yes it does. old fridge was useless.
I was thinking of leaving a 1cm air gap between insulation and hull to permit air convection from bilge up to cool the hull, and NOT let the insulation touch the hull. What do you think?

high end 12v freezers are unavailable here and far beyond my budget )


200 litres of freezer space is huge! how big is your boat?
where is it all?
I have a 200l fresh water tank!!

I also have another fresh bigger fresh water tank I do not use thanks to the water maker, but it is structural and uses the hull as part of the tank. Cutting into it from the top would ba huge undertaking

You need the 200 liters when you want to have provisioning for 9 months. I believe you asked about 6 days, which is much shorter… 45 times shorter to be exact, so for that 200 / 45 = 4.5 liters will do. Maybe this puts it into perspective.

What is different is the ratio freezer:fridge for such short passages. We need 100 liter fridge so that would translate to just over 2 liters fridge in addition to 4.5 liters of freezer but for just 6 days I think you probably want to swap that and go for 2 liters freezer and 4.5 liters fridge.

Our boat is 64’ and we have a watermaker

[Simi 60]

I reckon we have it about right.

A 5 draw 125 litre freezer
A 500 litre 4 door fridge freezer (180 litre freezer)
A 125 litre bar fridge for cold water and adult beverages
And in summer a 2nd 125 litre bar fridge on the upper level so as not to have to go downstairs for a beer.

All 240v standard household units
All running 24/7 on battery/inverter/solar.