Portable Absorption fridges on boats

[alcam]

Can anyone advise me about the use of an absorption fridge on a sailing boat?
I was considering getting a portable WAECO 3 way absorption fridge and was wondering if properly secured on board would it be a good or viable idea to run it on gas when on the hook for a few days. I sail in the Mediterranean so summer temperatures can reach the high 30s. My old system packed up and I am trying to find the best solution. I don't know much about these type of fridges and don't know of anyone who has one on board so any help or advice would be most useful.
Any suggestions as to the best type of refrigeration (not necessarily the most expensive)?
Thanks to all.

 

[Gordonmc]

I installed a 2-way (12v and gas) fridge on the boat to keep SWMBO happy, but have never worked out a way of venting burned gas fumes. The kit that came with the unit was fine for installing in a caravan where the vent goes out through the side, but useless on a boat. The only way I came up with was to vent using a 12v computer fan blowing fumes up a flexible duct through the coachroof.
The fan defeats the object of saving battery drain, in addition I would be happier with a passive solution that gives some certainty of getting rid of CO1 without relying on a fan.
So, I only have the fridge on (12v) when I am on shore power or the engine is producing amps.

 

[roger]

Why not a comprssor fridge?

We made up a fridge enclosure to fit a smallish space on the boat using expanded PVCU and celotex insulation. Then fitted a Waeco fridge working parts kit. It works well. The alledged power consumption is 3.5 amps and the duty cycle is never more than 50% and usually less.
For Med. use you would be better off using a watercooled hot end. Also its quieter. The air cooled ones have a fan that is perceptible in the night.
The only worrying bit about the installation is fitting the two halves together. You get just one chance!!

 

[Porthandbuoy]

I had a 12Vdc / 220 Vac / gas absorption fridge on my 9m Catalac. We never used it on 220 Vac and on 12 Vdc it sucked the battery flat in no time.
On gas however it was very economical, but you have to appreciate that the absorption method can only reduce the temperature approximately 20 degreesC below ambient. That's OK in Northern climes, but in the Med, when it's nudging 40, it's a different story. Don't expect ice cubes or beer cold enough to frost your glass.

 

[dick_james]

Absorption fridges are just not the solution for anything other than river craft. Apart from ventilation issues they only cool 20-30 degrees below ambient and need to be pretty level. I got so frustrated with mine I hauled it out and fitted a compressor version. Terrific difference.

 

[Anonymous]

For the Med you definitely want a compressor fridge and you will be very glad to have gone for water-cooled rather than air-cooled. Not only are water-cooled much more efficient and effective, you don't get all that heat in the living accommodation.

 

[trouville]

I have a compressor fridge on my Hillyard,And added a supercool element,to prolong the time between runing the engine,while motoring i could soon have ice! but after one day at rest, the following day would see about +9 degrees in the fridge.

When i get around to it im going to throw my compressor overboard and fit an Isotherm system, ive seen on working aboard a boat in Italy and with a large solar panel he manages to have +2/3 maximum during the mid day afternoon period.And with no shore power in summer never has had a battery problem.

 

[Anonymous]

[ QUOTE ]
When i get around to it im going to throw my compressor overboard and fit an Isotherm system, ive seen on working aboard a boat in Italy and with a large solar panel he manages to have +2/3 maximum during the mid day afternoon period.And with no shore power in summer never has had a battery problem.

[/ QUOTE ]There's a terminology problem here....the Isortherm fridges are compressor fridges, with a sealed rotary compressor just like a domestic fridge or freezer. Absorption and Peltier are the other types and are very inefficient. The engine-driven compressors are rather differerent in that they are reciprocating compressors and have piston and crankcase seals to fail. The engine-driven compressors are very powerful and lend themselves to charging up large holding plates but the seals can fail leaving you needing a specialist to service it.

Mine is an Isotherm with keel-cooling and a large solar panel. Even on a cloudy day in Chichester in March I can run the fridge as a deep freeze combination and still have spare power from the solar cells.

 

[trouville]

Do isotherms have an electric motor sealed into the system? Ive often looked a domestic fridge systems which are called "compressor" and wonderd if they could be adapted?

My compressor fridge lived in a locker for years,and i went each morning to by ice! When i finaly fitted it it worked wonderfully it cooled so well the holding plate froze and pushed itself off the firdge wall!! and the holding plate is heavy gauge stainless!!

Its not a solution for me as i stay in ports or anchorages sometimes for weeks without needing to use the engine,and the supercool just keeps thing "cooler" and helps the ice last longer.

The other reson for taking it off again was that the liquid was no longer available,to top up,and while it can be found from garages and recycling?? i was told its getting harder to find.

Last year i was suprised how afordable Isotherms have become? And the Norwigen in Elba has said for years that an electric "compressor" firge is the most practical and works very well.And everyone gets fed up with charter boats that run their engins every 2/3 hours to keep the deep freez frozen!!!

Ive never heard of a fridge with keel cooling? The one in Elbe runs on a 80/90 watt panel and i almost never use my 80/90w panel as i dont use much power,an 18w plus 36w (untill i broke it) provided all my needs.

Will an Isotherm freez? dose the holding plate get so cool. I was going for the small model? but not this year, as i have another boat and no money!!!

 

[Anonymous]

Yes, the Isotherms have a sealed compressor just like the type you see on domestic refrigerators, freezers and air conditioners. They have a solid state inverter as part of the package to drive them from dc, since this type of motor does not run on dc. Mine draws 2.5A and the evaporator (cold part) chills a large box greater than 600 x 600 x 500, the bottom 1/3 of which is at minus 15C when the top is around plus 3C. The compressor runs most of the time, I haven't checked the duty cycle but it is silent and I have plenty of power. If I wanted to save power I would turn it right down and do without a freezer, then it would only be on for a few hours a day, I think. I have a 360W solar array so don't have any problems at all with power for this, even in England on a cloudy March day.

Keel cooling is quite common for boats intended to go through the tropics and the Caribbean. The condensor (hot part) is a plate on the keel. If you don't want to do that, there are skin fittings that have a heat exchanger for fridges - I don't recall the details but someone here will know where you can get them and whether they are worth having.

 

[Petercatterall]

I survived several years in tented camps in the middle east. We used simple canvas bags to cool our drinking water, and sometimes cooled canned drinks in these bags. On occaision we put cooled water into cool boxes, discharged camping gas cylinders into the water, added cans of beer and presto..cold ale. Its horses for courses you can soon get used to cool (rather than cold) drinks. All fridges need to get rid of heat somewhere and will rapidly raise the temperature of a small cabin from bearable to 'orrible'
Cheers