HVAC Idea, please don't flame me

[Chasemmc]

My aft stateroom split unit is slowly leaking refrigerant. My local AC guy says use 'stop leak' to get a few more years out of it. But in the course of the discussion I had an idea. (I know, dangerous)

Whereas the new 'all in one units' require coolant to circulated at the air handler, is their any merit to the idea of repurposing the the copper lines as a coolant lines? While the stop leak may not work long term against the refrigerant pressure, perhaps it would hold with a low pressure water line.

If the consensus is that the copper would take a dump due to the corrosive nature of sea water, how about running a closed loop antifreeze solution or light oil to small heat exchanger placed where the old compressor split unit was located.

Any merit, or am I smoking rope?

[Captain Ralph]

Not knowing where your leak is shoots the idea down first (in the copper).
Next issue, not enough flow because of the small tubing size.

Thru the years I have tried different AC stop leaks. The later stuff that Johnstone sells is in an in-line kit that seems to be working the best in my past uses of it.
With the dye, a mini black light helps find the leak after some use. Usually the service valves, then the schrader valves. Bad or loose flair at the copper connect. I have found leaks in the copper tubing also.

Pass me some of that rope

https://www.johnstonesupply.com/product-view?pID=B87-218

[Pascal]

Copper will corrode in no time and they are a bit too small to carry enough water anyway.

As to using a loop, it s a lot of trouble and extra parts plus you still have the pipe diameter issue

Has your tech located where the leak is with a sniffer ? It could be in one the pipes or in spot that is easy to repair. I ve had good luck getting air handlers welded in the past

[Scott Mather]

I have done exactly this using the old copper lines. Remember there are (2) refrigerant lines running to the old air handlers, tie them together for enough capacity.
Are not the cooling lines on the old compressors copper? I would think the corrosion issue would be no different.

[Captain Ralph]

Are not the cooling lines on the old compressors copper?

Copper-nickel.
Notably different,

[Chasemmc]

Haven't used the dye yet. Just dreading having to run new waterlines from the gen room, through the VIP ,then the engine room, and finally to the stern. Trying to get perspective on the cost / value of repair vs. Replace. Then I can determine the value proposition of a new unit.

[Pascal]

I ve never been a big fan of self contained because of the noise although it can be a big money saver. Indeed on a 56 running the hoses will be harder since the VIP is forward of the ER and the AC is in the gen room. Have you considered putting a small pump in the ER which would considerably shorten the hose run? A short haul in the slings just to add a TH maybe easier and cheaper than running hoses from the gen room. Long Hoses which will need to be descaled regularly

Before making auch a big decision, you need to get someone on board with a sniffer to find the leak. Not dye. I had this done quite a few times on my 53 when I had splits and on boats i ran with splits. The leak could be easily repairable if in a connection or the evaporator

I just so glad I was able to convert to chillers 5 or 6 years ago when things were much cheaper and I had most of the interior gutted anyway.

[q240z]

When we bought our 1968 Chris Craft Commander 42, it had a window shaker AC unit mounted on plywood that was wedged in the salon sliding door opening that would normally open to the side deck. PO said the OE ACs didn't work. After we got the basics done and were using the boat, I had an HVAC guy come by and charge the ACs. Both came on and worked fine in cool and heat modes. 24 hours later, the compressor for the salon unit wouldn't come on. HVAC guy came out again with a dye kit and found the Schrader valve was leaking. $2.50 for the part and more for the recharge. The system worked fine (albeit loudly) for a decade until we sold the boat earlier this year.

Word has it modern rotary and scroll compressors in self-contained units are quiet enough to be mounted under bunks and not make much more noise than the blower fan.

[Pascal]

Five years ago, I used a self contained for about a year after the master split failed and while I was deciding whether or not to go with chillers. At that point I had already combined the master and VIP so I installed it on the VIP closet, against the ER bulkhead. That’s about 15’ from the head of the bed. While not very loud, it was louder than the blower. And much lower than the air handler I have in the same spot now.

[cww]

I would just fix it properly. There's like a 99% chance the leak is in one of the valves at the compressor. I don't like self-contained they're very loud, to the point I found it difficult to watch tv with the one in the master in my old boat. How much are split systems these days that everybody is going this route?