Refrigeration Alternatives

[Moonstruck]

You guys are forgetting the lowly styrofoam coolers that you see as you walk out of a Walmart. I had one that lasted 3 years carrying food to the boat and the mountains. I formed a bond with that cooler. When the corner cracked, I put tape on it. It finally split all the way down, and I had to chuck it. It was a sad day. Liberty Mutual didn't even call.

 

[FF]

For the adventurous folks , this was lifted from another board,

Free deck fridge that requires no electricity
All sailors should be aware that you can make a free off grid fridge that works well with no electricity. I'm sure anyone could make this for free if they desired.

The science behind these fridges has been cooling food and drinks for over 3000 years, and they are ideal for sailors because the wind, water, and sand required to operate it are easily at hand.

All you need is a couple of plastic bags, some sand, and some water.

It is called a "Zeer Pot Fridge", and I've linked several Youtube videos describing them below. You could build one in 10 minutes and cool your food by 40° (rough) without electrical power.

Typically it is built using pots instead of bags, but I wanted to emphasize the simplicity. I could make one with a few empty boxes and some sand.

If you want a secondary fridge on deck for your beer then a Zeer Pot maybe your answer. They would work great in wind on deck, but not so much in a cabin or galley.

Yet the cost is free for the electricity, and is free to build depending on what you want.. This is assuming you scrounged the necessary bags or boxes, but I'd advise a small investment.

There is probably a hundred Youtube videos on how to construct a Zeer Pot, but this is how Ice was kept frozen back in ancient Rome/Egypt/Mesopotamia. (kinda).

PLEASE SHARE THIS INFO SO OTHERS DO NOT NEED TO FUSS WITH ICEBOXES AS MUCH.

Okay... This is in Boat Design Section. This is because a) I see no refrigerator/galley section to the forum & b) an enterprising designer could build one or more into their ship once they understand the simple mechanics.

They normally require wind for evaporation, and water must be added from time to time. Oddly enough a lot of sailors have an unlimited supply of wind, water, and sand.

This is how the ancient Romans/Egyptians would refrigerate on their ships. It is simply a forgotten technology that keeps getting reinvented (long story).

I will link to a video on youtube, but find your own.. there are many.

This pot seems to use dirt instead of sand... Anything similar would work. Charcoal, sponge, etc. A person could put a few tiny flowers in the dirt section possibly. I wonder if that would aid evaporation? I mean the plant would suck away some of the water.

It works the same way your body cools itself. These clay pots are porous so help the liquids evaporate.


and also

Even rich sailors might wish for a secondary deck fridge. Not exactly an Isotherm or your preference, but it's perfect for sailors and can cost less than a dollar if you want to be frugal.

NOTE: Fresh water evaporates quicker than salt water and is more effective, but ocean water would work in a pinch, but your beer would be a tad warmer. ALSO.. A round zeer pot fridge will cause the wind to circulate around the fridge easier, and this would also aid in the evaporation process that is required.

There are misconceptions about Zeer Fridges so make sure you understand the mechanics fully before building one. i.e. They won't work in your kitchen because they need wind/sun for evaporation. Some have also tried using other liquids such as alcohol which does evaporate quicker, but is more costly and loses some heat transfer values. Water is best. Porous containers (especially outer) is also advantageous. Bags would work in a pinch, but not advised for best results.

Clay pots are porous and allow evaporation. You may notice that the "Sudan Video" (first link) had the fridge suspended in the air. This allows water to evaporate through the bottom of these pots also. The interior pot is also clay and allows water to evaporate from the exposed fridge interior. If you could keep the interior walls clear a tad it would also aid them, but not necessary.

I've heard of people using screening to hold the outer sand. That certainly would be more porous and keep things cooler, but I've not tried that one yet.


This evaporation process is just a simplified process of what occurs in your fridge at home. Evaporated water takes a lot of heat with it.

If you are moved by this information.. please spread the word...

p.s. unrefrigerated eggs last up to 4 times as long if you coat them lightly with vaseline. An old time sailing trick. Eggs have pores that let in air and water. This is why Hard Boiled eggs weigh more.

Save some bilge-sucking scallywag from scurvy.

 

[Jetstream]

I've noticed there is not much talk of eutectic refrigeration. I had a eutectic freezer in a game fishing boat I owned at one stage driven from a belt driven compressor on one of the engines. It was very efficient and after the initial couple of hours running to cool it down only needed about an hour a day running to keep it frozen. Are they not used much any more?

 

[FF]

Eutetic is as wonderful and efficient as always.

The hassle is it mist be installed (lots of parts) very well to operate.

Simply throwing a house style box in place is easier for the boat assembler.

As batteries get better (someday we hope) and DC sealed cans grow in size , perhaps there will be a return for Eutetic.

On our 90/90 we run 2 hours and have frozen (+5F) food and a good sized fridge (34F) for 4 days between running.

The price is a huge volume of boat reduced to a modest reefer system.

6 inches of freon blown insulation on top 4 on the sides . plus 22x22 3 inch thick eutetic plates in the reefer reduces the volume a great deal.

Fine on a custom build where its planned for , difficult in a production boat.

For most production boats the option of an interior that could accept a 12v DC Sunfrost unit would be a big help for the non dockside.

 

[Art]

We keep it pretty simple...

Using inexpensive apartment sized AC Refrigerator in galley area:

When arriving at boat to load-up for couple to several days out and about - utilizing dock AC, we turn frige dial to # 7 (its coldest) and put in pre-cold food from big cooler. Ice from home freezer is then placed into a container and put inside small freezer that is on top in the boat refrigerator.

We open frige door seldom and close quickly. Our gen set usually runs .75 to 1.5 hours in morning and evening for charging batts, cooling frige, charging computer/phone, coffee/cooking... etc. Even in hottest times we usually only need to refresh the ice container inside frige once in two days. Although we do not keep frozen food and keep most drinks in small cooler that is iced we spend fairly little $$$ to consistantly keep cold food/drink aboard.

Happy Food-Cool Daze! - Art


PS: We keep a tall Igloo cooler, in the shade and wrapped in thermal blanket, for replenishment ice only.

 

[bayview]

"USCG forbids their use in boats."

CHARTER BOATS,, not recreational vessels.

The GC has less control over the dangerous activities of pleasure boaters

 

[High Wire]

A 150 qt Igloo is about $60 at Costco or Sams. Line the bottom with 8# block ice and go. That will last at least 5 days. Refill when stopped in a marina or dinghy in. Once you get home you can set up a permanent solution. We have a very expensive Frigid Rigid power cooler on board and we still use ice blocks. Running the gen for an hour in the morning and night keeps the blocks whole for weeks. Frozen food sitting on the ice blocks stays frozen and the stuff on top stays 35-40F.

 

[BruceK]

Years ago it was common here for cars to carry a canvas water bag hanging from the front bumper bar(they were made of chromed steel then, not painted plastic). There was a cap on top of the bag for water in and out. In an hour or so of driving the water was so cold you got an "ice cream headache" drinking it. Tasted odd, but very cold.
Can`t see why it wouldn`t work on a boat (except for glacial trawler speeds with no breeze), I still like my eutectics and Danfoss powered 12v fridges.

 

[Jetstream]

Years ago it was common here for cars to carry a canvas water bag hanging from the front bumper bar(they were made of chromed steel then, not painted plastic). There was a cap on top of the bag for water in and out. In an hour or so of driving the water was so cold you got an "ice cream headache" drinking it. Tasted odd, but very cold.
Can`t see why it wouldn`t work on a boat (except for glacial trawler speeds with no breeze), I still like my eutectics and Danfoss powered 12v fridges.

I remember the old canvas water bags. We used to hang them on the bull bars of our trucks and cars and they were very effective. On the cattle stations we had meat safes that worked the same way with a canvas covering that you use to pour water over. They are very effective in drier environments because the evaporation is the source of cooling. I don't know how they would go in a marine environment with high humidity.

 

[2dboat]

Older thread... but I was searching "Propane Refrigeration" and this thread came up. When we bought our 1981 38ft Cheer Men Europa sedan, she came equipped with a Norcold ~7cuft RV fridge [115ac/12dc & LPG]. 1993 vintage & still works.
Now, if anyone had ever asked me about a propane fridge on a boat I probably would have told them its a bad idea and when we first took ownership of SAN-BAR a new DC fridge was on the top of the list.
However, once we cleaned the flu-stack to get out the spiders and dust bunnies [boat had been in storage for 18 months] and replaced a smelly hose at the tank, it has worked brilliantly. Yes they produce a lot of heat, but the prior owner had sealed off the vents into the cabin and put large vents top and bottom behind the fridge in the side of the cabin and on a hot day we can run two 'muffin fans' to help the airflow as well. Fuel consumption is very low as noted elsewhere in this thread.
Since it works we'll keep it, but honestly when [if?] it croaks I'm not sure why we would not install another similar unit. We do not have nor want a generator, and the propane vs. compressor aspect allows us to operate modest house battery banks topped up by 100w of solar.

•Marine Surveyor blessed it.
•Insurance company knows it is there.
•Also have a propane oven/stove so we would have tanks anyways.
••What's the down side?

 

[Lou_tribal]

We have a hand made cooler in one of our front bench. Insulated with 3 inches of foam, glazed with fiberglass and painted. The cooler has a shower drain type grid and a double bottom where to collect water. THe grid can be closed like for a sink if I want to keep the cold water to cool my bottle of wine, and the double bottom has a small bilge pump with a floater switch so the water is expelled out through the galley sink throughull. We can keep 2 bags of ice during at least 3 days there and even more with a ice block and does not need energy except for the few second to pump the water out.

 

[kev_rm]

Older thread... but I was searching "Propane Refrigeration" and this thread came up. When we bought our 1981 38ft Cheer Men Europa sedan, she came equipped with a Norcold ~7cuft RV fridge [115ac/12dc & LPG]. 1993 vintage & still works.
Now, if anyone had ever asked me about a propane fridge on a boat I probably would have told them its a bad idea and when we first took ownership of SAN-BAR a new DC fridge was on the top of the list.
However, once we cleaned the flu-stack to get out the spiders and dust bunnies [boat had been in storage for 18 months] and replaced a smelly hose at the tank, it has worked brilliantly. Yes they produce a lot of heat, but the prior owner had sealed off the vents into the cabin and put large vents top and bottom behind the fridge in the side of the cabin and on a hot day we can run two 'muffin fans' to help the airflow as well. Fuel consumption is very low as noted elsewhere in this thread.
Since it works we'll keep it, but honestly when [if?] it croaks I'm not sure why we would not install another similar unit. We do not have nor want a generator, and the propane vs. compressor aspect allows us to operate modest house battery banks topped up by 100w of solar.

•Marine Surveyor blessed it.
•Insurance company knows it is there.
•Also have a propane oven/stove so we would have tanks anyways.
••What's the down side?

The propane units are very common in the land yacht world (RV's). You definitely want to vent the coils with fresh air both at the bottom and top, they rely on this.. I would not run one where the burner or coils were actually inside.

They are, however, SUPER efficient and have no real moving parts, you can run one for two months on a standard grill tank.

One caveat, they do clog up if you run them off-level and replacing the guts is very expensive, and most folks opt for putting in an electric unit when faced with that repair.

 

[Lobstah]

And a side note...when "running" on propane, they still require 12vdc to operate. Not much draw...but has to keep the circuit that monitors the temp sensors alive.

 

[johnrupp]

And a side note...when "running" on propane, they still require 12vdc to operate. Not much draw...but has to keep the circuit that monitors the temp sensors alive.

The newer ones might use 12 volts for sensors but the old ones don't. We have an older model 3 way Dometic at our hunting camp that works fine with just gas. No electric at camp, AC or D.C. Just propane lights, stove, fridge etc.