Propane powered refridgeration?

[vilanomark]

I was looking at a sailboat today, and while I was aboard the owner showed me the fridge. After a few minutes he showedd me where the propane tanks were kept and I asked him long a tank would last him. He responded that while cruising he could cook and keep the fridge going for roughly 4 weeks. I asked him about the fridge part again and he said yes, he uses propane to keep the fridge going.
I know I am a novice, but what type of system uses propane to keep a fridge going? If it's as simple as hooking up a special unit to use a propane tank to keep your fridge going, then why don't more people use them?

[Steve Kidson]

Not sure of the technical details, but there are fridges designed to run on LPG (propane). These fridges normally will run on other energy sources, AC and/or DC, and so are popular with travellers.

In Australia, in my experience, this type of fridge and installation is more commonly found in caravans or motorhomes. We have strict regulations in relation to LPG installations, appliances and storage, and these can present some challenges in a boat.

I have not had any direct experience with such fridges, except as a kid we had a caravan with one of these, and as I recall, it worked OK.

Good luck

Steve

I have quite a bit of experience with them. They would not be my first choice for a boat fridge. Honestly, I am not even sure they are legal for marine use. There are several different types, including the three way power that will run on AC/DC/LPG. The issue is the danger of a pilot light on board a boat. I have a full size propane fridge in our off the grid cabin. It does not get anywhere near the economy that was described to you. WHen we had the smaller RV style unit in the house, we could get about 2 weeks from a 5 gallon tank. My opinion is that this is not a selling point for the boat, but I am sure some others may disagree. If I were to purchase a boat with a propane fridge, I would immediately replace it with an AC/DC unit.

[roverhi]

Propane frig's have been around forever. They are quite efficient and a lot more long lived than conventional frig's 'cause they have no moving parts. The old Servels were selling at a premium even though most were 30 years old. We lived with propane refrigeration for years and it worked fine if you can live with a 12cu' frig that was not self defrosting.

The biggest problem with them is they do not work properly unless the frig is near vertical. Thus not for a sailboat, or any boat for that matter, underway. Another problem is most of the ones that you see on the market today were built for RV's. That means they weren't built for longevity or even efficiency. There are quality one's out there but they are quite pricey.

They are reasonably efficient, depending on the quality of insulation. With the rising price of oil, may not be cost effective in comparison to other energy sources. I wouldn't discount for the refrigeration but probably wouldn't add any additional value for it, either.

Aloha
Peter O.

[Euro Cruiser]

I would consider a propane fridge to be a negative selling feature, to the same magnitude as replacing the unit would cost. Just like kerosene-fueled refrigerators, one of the operational requirements is that fuel is always available to the burner so it can perform its evaporation cycle. This means a boat owner has an open propane line running from the tank to the burner, with propane control being 'automatic' and one being dependent, 24/7, for safety sensors to work (e.g. a heat sensor which will shut a control valve). I simply don't think this is a seamanlike choice in any boat...but when you add the challenge of this system working without fault while the boat is sailed, the odds go even further against you.

Like KN, I'd opt for a DC-powered replacement; I'd limit the priority of this change-out only as far as my willingness to live without refrigeration.

Jack

[Talbot]

Lots of good answers from a monohull viewpoint, but a lpg powered fridge makes quite a lot of sense when it is fitted in a catamaran. I have had one in my cat for 18 years without a problem!

The gas used for cooling is different to normal fridges (an ammonia mix if I recall correctly). These fridges are hopeless on 12v cause of the power required, but will work fine on mains and are then controlled by a thermostat. When powered by gas, there is no thermostat, the amount of cooling is controlled by the gas flow setting, so it is permanently on. You do need to consider the venting for carbon monoxide.


Mine is now 22 years old and really needs re-gassing cause it is not getting as cold as it used to

Gas consumption even on "high" is very frugal, and is a cheap alternative to other options

[vilanomark]

Talbot, the boat I was looking at was a 34' Gemini Catamaran. The owner said he hadn't had a problem with his system, however, the boat and system are only 2 yrs old.

[Talbot]

Exactly - a fit in a cat! I have no idea what their performance is like in hot clime, but you should be able to find out from a caravan forum.

[Euro Cruiser]

My reservation has nothing to do with mono vs. multi. I think the continuous flow of propane, from a secure remote locker into the rest of the vessel, is a bad idea...and all boats that go to sea face their issues as they get tossed around, not just monos.

I'm glad Talbot is still with us...but his refrigerator suits a caravan rather than a boat, IMO.

Jack

[Talbot]

I have similar reservations about spirit stoves and boats that use 240v or 115v (as applicable) at sea.

There are more than 500 boats similar to mine , all of which have been going for more than 20 years, and all have LPG gas fridges. To date I only know of one that had a problem with their gas fridge, so I guess in a risk analysis that would make it a low risk despite the potential.

The level issue is one that I had not recalled until it was mentioned here, but it is a very important issue. Not just wuth propane refers, but all refers. Most manufacturers have a specification as to what angle the fridge will work at reliabley, and for how long. Talbot, I agree that this is less of an issue with multi's. I can also confirm, at least in the older units, amonia was used. These units were subject to rust issues as well. I had two of them develop leaks in the evaporater due to rust. Even these issues do not concern me as much as dealing with the pilot light. All of the units I had use a pilot light, and all of them had a bad habit of going out. This is not only a concern from a safety standpoint, but also from a convenience stand point. Although my Dometech (I think that was the brand) unit had a peizzo lighter for the pilot, the darn thing would only work about half the time. THis meant that I had to pull the unit away from the wall and get back behind it to manualy light the pilot.

[Talbot]

All of the units I had use a pilot light, and all of them had a bad habit of going out. This is not only a concern from a safety standpoint, but also from a convenience stand point. Although my Dometech (I think that was the brand) unit had a peizzo lighter for the pilot, the darn thing would only work about half the time.

Yes I had a short phase of this and removed the fridge and thoroughly cleaned the igniter and the pilot hole, making sure that I had the fridge upside down for a while, as a lot of the problems were being caused by dirt inside the pilot hole. A quick vacuum and refit (8 years ago) and it was (and is) working perfectly again.

Maintainance. THey key word on any vessel I never did figure out how to solve the problem on my refers. Still, the efficiency of 12volt refers has improved so much over the years. I would be hard pressed to consider propane as a viable option on my own boat. 4.6 amp draw with about a 25% cycle. 331.2 watts per day. One solar panel will accomodate this load. Zero cost to run.

[Talbot]

Cant and wouldnt argue that the performance of the modern danfoss compressor tied to a keel cooler and evaporater with at least 6" insulation is phenomenol. but it is 5x the cost of the lpg fridge.

It's only money