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Would an aircon compressor from a car work as a freezer compressor?


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Yes, very common. was the norm 30 years ago, but now most are going electric. Common ones on boats include the sanden sd508 units like this;

https://www.ebay.com/itm/A-C-Compressor-For-SD508-Sanden-Style-V-Belt-2-Groove-Pulley-3-4-7-8-AC-/122642099296

These used to be 2 grand! Currently the most expensive bit is the eutectic tanks...

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Kick has everything there less the compressor, hoses are sitting capped in the engine bay so my guess that will be the most economical was to het it all running?

 

Iv never purchased from ebay before :-/

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I do a bit of boat refrigeration work. Any idea why the compressor isn’t there? Has the boat got a new motor or something? It’s somewhat promising that they have bothered to cap the system, suggests there was something there worth looking after. Engine driven systems can be quite expensive to work on. On top of fitting the compressor, you should replace the dryer and sight glass, then it will need to be pressure tested with nitrogen, then vacuumed out for 12 hours at least. Then gassed up and run. If it hasn’t been serviced for a while you might want to acid wash the heat exchanger too. Depending what gas it had in it before and how old the parts age, you might want to look into the rubber hoses and gas lines also. If the system leaks, you then have to find and fix the leak and retest the system. If the system needs fixing later, you have to have all the gas removed by a reclaim machine, fix the leak and repeat the above pressure testing and vacuuming. They do work well when they work though.

 

The benefit of a 12v system is you know what it will cost before you start, and they normally give trouble free, maintenance free operation for 10+ years. Also, they can be left running at the dock for 24/7 cold beer ++++++++

 

If you have one refrigerated box, I’d say 12v would be cheaper, if it’s a seperate fridge and freezer box, you would need 2 12v systems, hard to say what will be cheaper then. Also depends on battery capacity and charging systems, pros and cons either way with that.

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Same as Mattm, I do this type of work as well. Let me know if there is anything you'd like me to do. There are plenty of the compressors on ebay that do deliver to NZ, the last Sanden one I got cost about $350.00 delivered. 

 

But yes, it will cost likely &1000 or so to flush, leak test, vacuum and fill. It could well be more (even lots more) if problems are found. The easiest solution would be the compressor model that was there before, so it fits the mounts. Got a pic?

 

Leaks in these system can be really hard to find, especially it its a 6 month or more leak.

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Same as Mattm, I do this type of work as well. Let me know if there is anything you'd like me to do. There are plenty of the compressors on ebay that do deliver to NZ, the last Sanden one I got cost about $350.00 delivered. 

 

But yes, it will cost likely &1000 or so to flush, leak test, vacuum and fill. It could well be more (even lots more) if problems are found. The easiest solution would be the compressor model that was there before, so it fits the mounts. Got a pic?

 

Leaks in these system can be really hard to find, especially it its a 6 month or more leak.

No mounts visible, not an issue as I can fab that up.

 

No idea why it has gone, boat was just raced and not cruised until the last owner who has only owned just over 12 months so guess it stopped working so they just removed the pump. As you say unsure what the issues were why it was removed

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On my 1020 I’ve just replaced the front pulley bearing, and electromagnet , on a Sanden 508 using parts sourced from AliExpress. And had it vacuumed, checked, recharged . Very happy with its performance now , all for under $500.

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There is a double pulley mounted on the front of the engine so that would have been to drive the compressor. Maybe the original installation made the mistake of mounting the compressor on the engine bed or hull, rather than bracketing off the engine. This can cause on going issues with the compressors seals. Also is there an existing condenser? This will be on the salt water feed side to the engine salt water pump

Greg at Fridgetech is supposed to have developed a 12V system that can connect into existing eutectic tanks. Might be worth calling him.

That is a reasonable size freezer on top (Quality Stainless?) With fridge underneath, will need a reasonable amount of grunt compressor wise to keep it cold

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There is a double pulley mounted on the front of the engine so that would have been to drive the compressor. Maybe the original installation made the mistake of mounting the compressor on the engine bed or hull, rather than bracketing off the engine. This can cause on going issues with the compressors seals. Also is there an existing condenser? This will be on the salt water feed side to the engine salt water pumpGreg at Fridgetech is supposed to have developed a 12V system that can connect into existing eutectic tanks. Might be worth calling him.That is a reasonable size freezer on top (Quality Stainless?) With fridge underneath, will need a reasonable amount of grunt compressor wise to keep it cold

Yes there is an existing condenser, everything is there minus the pump.

 

We have same size freezer on existing boat with a sanden sd508 and it has more than enough grunt, can freeze everything in 15minutes.

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You have to be very careful changing an engine driven compressor for electric. The engine driven units are several HP, and can move a lot of refrigerant, comprared to an electric one, which is often a small part of 1 hp. The eutectic tanks need to have the flow they were designed for to work well. This is why the tubes through the tanks are larger dia in the old engine driven systems, and a lot smaller in new electric eutectic systems.

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I would pressure test the system first before Buying a compressor and check the TX valve to see what gas the system was running on there will hopefully be a plate on the freezer box which will give access to the valve. Pressure system to about 300psi with nitrogen and leave for a week to check for leaks if system holds pressure then start looking at reinstalling the compressor .You can spend a lot of time looking for a leak and may never find it

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