# Why doesn't anyone use propane refrigeration on a boat?



## MedSailor (Mar 30, 2008)

RV manufactureres have been making refrigeration systems that run on 110V/12/AND Propane for many years. These systems are cheap and available everywhere due to the high number of RVs around.

Why have I never heard of anyone using propane refrigeration on a boat? I know these systems can last weeks on a modestly sized bottle of gas, which would remove the need for huge wind/solar arrays, Balmar alternators and AGM batts etc etc.

There must be some reason right? I just can't think what it would be.....









Seriously though? What about using one of these:
LP Gas Refrigerator - Norcold 323 on sale - PPL Motor Homes
with all the appropriate sniffers/solenoid etc?

MedSailor


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## RichH (Jul 10, 2000)

Probably for the same reason that ammonia gas refrigeration is avoided ... if you get a leak you get "!!!!". Propane gas in an RV if it leaks simply 'drains' to the tarmac; in a boat it 'drains' to the bilge. Propane 'sniffer alarms' arent 'foolproof'. 

Its all a 'safety issue'.


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## bljones (Oct 13, 2008)

it is used on cats, like the Gemini 105Mc and houseboats. The issue is that propane fridges don't work unless they are damn close to level and above the waterline, two difficult requirements on a monohull.


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## Capt Len (Oct 9, 2011)

If you park on a slope the RV fridge gets warm.eh. Then there's a down draft problem The electric side isn't as efficient as a compressor, me thinks. And then I think of BOOM. I've personally seen 3 boats and a house boat do the nasty. Oft gang aglee!


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## wise4 (Oct 26, 2010)

A propane frig doesn't need to be level as long as there is motion.... So sailing wouldn't be a problem.... The biggest issue is with safety.... Not only with a propane leak... But with the open flame required on a propane fridge....


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## celenoglu (Dec 13, 2008)

I once used one on a boat. They do not work if not level. Even the smallest waves stop their functioning. If you are sailing they will not work for sure.


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## copacabana (Oct 1, 2007)

I have one in my boat and it works great. Mine is a freezer and I get about 25 days on a 13kg bottle of gas. Mine is gimballed, though I leave it in the locked position almost all of the time. I might release the gimbal if the boat is going to be a long time on one tack and well heeled, otherwise no problem. The flame has gone out twice in the 2 years I've owned the boat, but it has a gas cutter, so it hasn't been a problem. I'm not sure it would be my first choice if buying new, but it has worked flawlessly for about 15 years now, which is saying a lot.


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## rugosa (Aug 30, 2011)

We had a full sized front opening unit on Herreshoff NY 40 in the 70's but only used at anchor. Had forklift tank on deck. Kept the liquid assets at room temperature rather than on the rocks:laugher Safety is the big issue as well as the market it overwhelmed with 12v DC units and that's what builders and aftermarket promote.


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## BreakAwayFL (Sep 20, 2010)

boom


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## copacabana (Oct 1, 2007)

I'm not sure it's any more dangerous than a propane stove. Change all the gas lines and put in good quality shut-off valves and I can't see any problem.


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## mitiempo (Sep 19, 2008)

ABYC doesn't allow for it and that is what surveyors go by. Insurance companies listen to surveyors.


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## copacabana (Oct 1, 2007)

Mitiempo, I can see how that might be a problem for north american boats then, but from a safety point of view, I'm not sure a propane fridge is a problem with the correct installation, or at least any more dangerous than a propane stove, water heater or heater.


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## mitiempo (Sep 19, 2008)

In North America propane water heaters don't meet approval either. With a stove or open flame heater it is assumed that you are there. With a fridge you often won't be. 

For example for a water heater to be allowed it has to have a closed combustion chamber and no pilot light. No water heaters that I know of meet these requirements with the exception of one where they say a closed combustion chamber is available.


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## ccriders (Jul 8, 2006)

BreakAwayFL said:


> boom


Or is that KABOOM!?

Also, since it is an evaporative process, efficiency will be affected by the relative humidity. Warm climates at sea level would find high temperatures near 100% humidity where the unit would be installed necessitating the use of lots of fuel and generating more heat inside the hull. Sure it can be done, but there are many reasons other technologies have been adopted.

John


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## ottos (Aug 12, 2008)

mitiempo said:


> ABYC doesn't allow for it and that is what surveyors go by. Insurance companies listen to surveyors.


Then all those nice Gemini's are going around uninsured?


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## mitiempo (Sep 19, 2008)

They are more the exception than the rule. In any boat I am aware of with a propane fridge or water heater the survey invariably asks for its removal as a recommendation that the insurance company sees. And I work on boats for a living so I see many.

As far as a water heater, it might be possible to meet ABYC with a closed combustion chamber vented outside only as long as it does not have a pilot light. I have never seen an installation like that though. I don't think a fridge could be installed that way though.


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## ottos (Aug 12, 2008)

A friend had a Gemini. It did have a vent which was under the wheel if I remember correctly. Don't know if it had a pilot or electronic ignition.


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## copacabana (Oct 1, 2007)

No pilot light on a propane fridge, just a small, constant flame. If it goes out for whatever reason there is a gas cutter, just like on a propane stove. Mine is not vented outside the boat, but the little heat it puts out doesn't really heat the cabin (my boat is well ventilated). I can understand avoiding a propane fridge if it voids your insurance, but I still think a propane fridge, properly installed, is no more dangerous than a propane stove. My propane freezer lets me use a single 165amp battery for all my house needs. When it finally gives up the ghost I'll have to think very hard about whether to replace it with a new propane freezer or go with a 12v system (which will mean building an icebox and all the woodwork involved).


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## Faster (Sep 13, 2005)

Copa is that common in Brazil? I've only see them on powerboats in our area. It's an attractive idea in some ways.. certainly on the electrical side of things - is yours a specialized version compared to, say, the general RV model?


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## copacabana (Oct 1, 2007)

Ron, I have to say I think I've got the only propane fridge in Brazil (as well as the only compoating toilet!). The previous owner, a very experienced German gentleman with 9 Atlantic crossings in this boat, installed it in 1997 during a complete refit. It's not a marine freezer. I believe it must be for the RV market (the brand is "Domec" I think). At any rate, it works very well and hasn't blown up yet! When it finally dies I'll be here asking for advice on 12v vs propane systems. Until then, it maintains the beer at exactly -3 degrees celcius. Who could ask for more?


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## Minnewaska (Feb 21, 2010)

copacabana said:


> I'm not sure it's any more dangerous than a propane stove. Change all the gas lines and put in good quality shut-off valves and I can't see any problem.


The difference is that you should only charge the propane lines running through boat when you're actually using the stove. A fridge would need to be charged all the time. A leak could fill the bildge while your sleeping.


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## mitiempo (Sep 19, 2008)

copacabana said:


> It's not a marine freezer. I believe it must be for the RV market (the brand is "Domec" I think).


It is probably a Dometic. popular in rv's in both Europe and North America.

As Minnewaska posted with a stove it is presumed you are there - with a fridge, often not.

I recall the Hiscocks aboard Wanderer had kerosene refrigeration - it had to be kept close to level to work properly. The propane fridges are similar, just the fuel is different. Virtually every rv has a 3 way fridge - 120volt/12volt/propane.

I doubt ABYC extends to Brazil.


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## copacabana (Oct 1, 2007)

Yes, it's a Domitec 12v/120v/propane freezer, although I would never run it on 12v as it would drain the batteries. It doesn't seem to be at all sensitive about working 100% upright. I rarely release the gimbal and I haven't noticed any loss of performance when heeled. All in all, it seems a good solution, although I'm not sure I would have installed it in the boat as my first choice. It came with the boat, and "if it ain't broke ..." 

I don't leave it running unless I'm on or around the boat. I suppose a gas sniffer with an automatic cut off valve in the bilge could be a solution to worries about an eventual leak.

Minnewaska, I never leave gas in the fridge or stove line. I have a valve right on the gas bottle that I turn off first and let the gas in the (very short) line burn off. Then I turn of the 2 individual valves, one on each gas line. The freezer also has a cut off valve if the flame goes out for whatever reason. I had a gas cutoff solenoid that I chucked in favour of high-quality manual shut-off valves, which I believe are more reliable.


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## Minnewaska (Feb 21, 2010)

COPA, it sounds like you're doing the right thing, but assume you either have no refrigeration of use electricity when away from the boat. Just a further thought on a gas solenoid. They do fail and are only intended as an emergency shut off and need to be installed back at the tank. Ultimately, to protect the boat, you need to spin the tank value as you do. What I really worry about is a leak along the line somewhere.


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## geoduck (Aug 12, 2011)

I like the option of a 3-way refer. Gas when sailing along. 12volt when motoring. Dock power when tied up.
You just have to make sure you dont blow yourself up. Simple enough. I sailed on an old timer built in 1898 that had kerosene refer - worked just fine as long as you kept the soot out and the burner clean. 
My refer is 12v or 110 - works good enough for me. I can live for 3 days without charging batteries. 2 roll up solar panels - 1ft x 6ft takes care of my charging as long as the sun shines.


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## Capt Mitch (Mar 27, 2012)

That should be obvious... there is waste gas... CO is produced and propane
is constantly depleted. 134A refrigerant is the current gas used. learn how to work with it.


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## deniseO30 (Nov 27, 2006)

Additional information if some of you may be interested. 
Absorption cycle refrigeration and air have been around a very long time. Yes the company I was with serviced them. personally I knew very little about them except they needed simple gas burner service to keep the running. The larger units worked as a "Chiller" and cooled a brine (around 38*) that was piped to the cooling coil on top of a furnace or blower unit.

Absorption refrigerator - Wikipedia, the free encyclopedia








Labeled photo of a domestic absorption refrigerator.
1. Hydrogen enters the pipe with liquid ammonia
2. Ammonia+hydrogen enter the inner compartment of the refrigerator. Change in partial pressure causes ammonia to evaporate. Energy is being drawn from the surroundings - this causes the cooling effect Ammonia+hydrogen return from the inner part, ammonia returns back to absorber and dissolves in water. Hydrogen is free to rise upwards
3. Ammonia gas condensation (passive cooling)
4. Hot ammonia (gas)
5. Heat insulation and separation of water from ammonia gas
6. Heat source (electric)
7. Absorber vessel (water + ammonia solution










Back in the late 50s early 60s there were quite a few gas ac systems in residences and even full size refrigerators being sold and installed, mostly by utility companies.

On boat, in addiction to the dangers of gas and venting, the thing may rust out quick because of steel piping.

A flame is not really necessary to heat the system as I believe the temp needed to start the cycle working is around 240* (why the flame is so small)

Anyways... thought ya'll might like to do some "additional" reading


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## Sionnach (Oct 8, 2015)

We have an electric / propane regridgerator on our Gemini 105M. We love it. Connect to shore power on the dock and propane underway or at anchor. We are actually thinking about installing a second in one of the aft bunks (we rarely use) for longer voyages. As far as safety, I haven't seen any data that makes them less safe than electrical fires, seacock leaks, or any of the other dangers sailor face to live the life. Propane alarms, good maintenance and safety checks reduce the risk to a tolerable level. As far as that goes we already have a propane stove and barbecue. IMHO propane is safe, cheap, and efficient.

That said... The Gemini is a catamaran which means we don't heal over. (I'm still getting used to sailing level.) So maybe not the best choice for a monohull.


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## deniseO30 (Nov 27, 2006)

Sionnach said:


> We have an electric / propane regridgerator on our Gemini 105M. We love it. Connect to shore power on the dock and propane underway or at anchor. We are actually thinking about installing a second in one of the aft bunks (we rarely use) for longer voyages. As far as safety, I haven't seen any data that makes them less safe than electrical fires, seacock leaks, or any of the other dangers sailor face to live the life. Propane alarms, good maintenance and safety checks reduce the risk to a tolerable level. As far as that goes we already have a propane stove and barbecue. IMHO propane is safe, cheap, and efficient.
> 
> That said... The Gemini is a catamaran which means we don't heal over. (I'm still getting used to sailing level.) So maybe not the best choice for a monohull.


 Old thread! 
They are pretty safe but would not bode in a rocking boat. venting, lines, and leaks are the big concern on any Marine LP system since it lays low in the bilge and is slow to dissipate.

I've a friend that has a G-105


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