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I have a fridge compressor dangling off the side of my engine and I don't like it. Put this together with the fact that we only ever use the freezer box as a chiller and even then not so much because the box seems to keep things quite cool all by itself whether I turn on the compressor or not...

So I would like to ditch the compressor and install a eutectic plate in my freezer for occasional use. There used to be one a few years back, a Tropicool I think, but now unavailable and from memory they were pretty power hungry.

Seeking advise here about where to find something similar and whether they're any good or not.

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Do you want to run in it as a fridge or freezer? Big difference in power consumption and hence battery bank size and charging system.

If you are just going for fridge, simplest option is an evaporator plate and compressor kit from www.fridgetech.co.nz .Keep way from their salt water cooled units.

Next up in price and complexity are the eutectic type units, such as the Ozefridge that IT represents.

Finally Fridgetech have a large 12V compressor that they say can be a straight change out for an engine drive compressor. I think they have only installed a couple of these so not a lot of history.

If you just want a fridge, go for the simple evaporator plate and air cooled compressor. I have 2 of these in small fridges and they are great

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Just wanted to run it occasionally as a fridge and even then not looking to lower the temperature much. The box is small which is why I had one of the old tropicool units in mind. Just install it in the wall of the chiller box and connect it up to the switchboard and you're good to go.

And underlying this is the main requirement - cheap!

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Chris, they are called a Thermoelectric cooler, Solid state refrigerator or the technical name is a Peltier heatpump.
They are indeed power hungry. About 6-7 A continuous for a device capable of cooling a large chilly bin. They used to be common as, but having aquick google, I could not find any Nz company selling them. It was a quick look though. Dirt cheap on the overseas sites like Allibaba.
 

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Thanks Wheels. I didn't run my freezer at all over the winter and I think I lost all the refrigerant because the seals dried out.

I don't want to re gas it.

It seems to me that engine designers build their engines to sit nicely on its four legs. Then yachties come along and hang a humungous belt driven compressor on one side and probably throw the whole engine installation out of balance. When I replaced the engine mounts recently I did notice that the mounts on the compressor side were a lot worse than the ones on the other side. Probably this compressor business is not an issue on big engines but mine is a little three cylinder Perkins. That's why I'm looking for an alternative, preferably a cheap one.

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what about a second hand 12v compressor type fridge , danfoss or vitrifrigo? use complete or as parts to cool your box.  They are very efficient and use little power.

I had a tropicool and it was not worth using, better to just use ice in your existing box.

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Or look for a second hand Dehumidifier that uses a compressor fridge unit. I did this. I have a Bar fridge (one of those Mitre 10 things) that had one of those Peltier units and that had failed. Every now and then a dehumidifier comes in for recycling and so I pulled the one apart and inserted the cold part inside the fridge and the Hot part on the outside. Then a small fan to cool the hot part and a thermostat and bingo, I have a compressor bar fridge. The dehumidifiers can often be bought cheap. Worth looking on Trademe. They are easy to pull apart and the Hot and cold radiator parts are separate and easy to pull apart and as long as you are really careful with the copper tubing, you can bend them around into a different orientation fairly easily. Some models are easier  than others to work with. Even though we get ones that are not working, the fridge units are always fine. It is usually some little switch or fan that is faulty.

Oh and those engine driven compressor units can be expensive to fix. It is never as simple as just regassing.
 

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waeco cfx 40,running on cool continuos does not use a lot of power,providing you put pre cooled products in. I have one very rarely put it on freeze,run on 3c ,never had a battery issue,they cycle on and off.Other brands seem to run continous for little cooling effort,stay away from waeco tropicool,

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What Harry said re the weaco compressor versions.

 

I have seen the odd one of those a bit fecked up but still running. Maybe you could score one that has a buggered body but good running gear and strip it.

 

Just in case anyone got lost there I am talking fridges not a hooker well past her use by date  ;)

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It seems to me that engine designers build their engines to sit nicely on its four legs. Then yachties come along and hang a humungous belt driven compressor on one side and probably throw the whole engine installation out of balance. When I replaced the engine mounts recently I did notice that the mounts on the compressor side were a lot worse than the ones on the other side.

Or does it have to do with the direction of rotation of your engine? One side an upward force the other a downward?

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Or does it have to do with the direction of rotation of your engine? One side an upward force the other a downward?

Oh! You know, I've never considered that but I can see how that could have a bearing on which side the compressor should be mounted. Looking from the flywheel, my motor runs anticlockwise and the compressor is on the right hand side. The alternator is factory mounted on the left hand side which I assume would be the preferred side for the engine rotation?

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The torque force of the engine when under load is likely the main reason the mounts squash on one side more than the other. The engine will be trying to rotate, and the mounts bolted to the bed stop that, so as the rotation is sent to the propeller. As the load resistance opposes the rotation of the prop, that is sent back to the Engine/mounts and the engine leans over in the opposing direction to the force. So the mounts of the opposing side to rotation are squashed and the mounts on the side of rotation are stretched.

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Winter, there have been too many failures of the water cooled units to consider them. Have a perusal of the internet. I know of a couple of local failures. Problem is corrosion in the condensers and when these hole you have one dead compressor. My suspicion is that the Danfos/Secob compressor have stray electrical leaks causing this. Remember these compressor are designed for caravan fridges and portable coolers, not for the marine environment

The Ozefridge water cooled versions take a different approach, they have what is effectively a radiator with an extra set of tubes for the fresh water cooling circuit. So there is separation between the water and refrigerant, the heat is conducted by the radiator fins

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A couple of things. Engine driven compressors are really car Ac compressors. They are a couple of HP or more. NO 12v system I've ever seen could come anywhere near the cooling capability of one of these. They used to be very expensive, but now you can buy a new compressor, say a sanden sd508 (very common) for around $400. Yes, the seals can leak, they are cheap - circa $40- but the other issue is that over time the rubber hoses fail and become permeable. This system is the same as a car Ac - you don't regass them every year do you? Well set up, they should do 10 years. To flush, replace the hoses, change the oil, filter, drier, and regass with a modern gas is normally about $2500.

Oh, and the compressor has NOTHING to do with the engine mount issues - they do wear out - they take a hammering in a marine application compared to a car.

Water cooled systems are great! Water is a much better heat sink than air, and smaller, more efficient units can be made. However, the salt water versions need, like most things on a boat, proper maintenance. The good ones have anodes in the condenser units. Without that, they will die quite quickly. The other solution is fresh water cooled - like the ozefridge

.

Yes, I sell those, and service both 12v and engine driven systems.

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I had a Sanden compressor on my last boat and it was a very nice unit - about the size or a little bigger than an alternator. The size and shape of the compressor means that it could be mounted very close to the engine, well within the footprint of the engine mounts which in turn meant a short V belt.

On my present boat I have a Mitsubishi compressor of a type used in Mr.Whippy vans. It is large and unwieldy which necessitates it being mounted well outside the engine mount footprint. And as a consequence has a long belt that whips all around the place. By this I am not implying that engine mounted compressors are no good, just that my particular setup is no good and that's why I want to replace it. Also, fridge/freezers are not very high on our list of priorities so that's also why we are looking for some sort of cost effective alternative. The adapted dehumidifier a la Wheels appeals to the Heath Robertson in me.

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if you want and evaporater place 1m long, used to keep my 1020 freezer at -18 you are welcome to it,  only 12 months old and currently sitting on my workbench until the wife accusses me of being a horder and throws it out. Has connections to connect to an Isotherm DIY compressor.  

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Thanks for the offer Rawhide, and sorry for the late reply - on the boat for a few days trying to kid ourselves that the weather is really quite nice for sailing.

We are going to use the freezer box as an icebox for a while and see how we get on with that. Thanks again.

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I pulled my whole engine fridge out with the intention of replacing it with a 12volt one never got round to it so we just freeze a ice block 10 litre gets us about 4 to 5 days it is only a couple of times a year we use the boat more than that.After 5 years of this I said to my wife shall we fit a unit she said why bother we get by.Engine compresser units are by far the best trouble is most are 30 + years old if they have a leak can be very hard to trace and it is now illegal just to top up with gas.I think I am the only refrigeration engineer that doesn't have a frigde on his boat .

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