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?

 

[q240z]

While not very loud, it was louder than the blower. And much lower than the air handler I have in the same spot now.

Do you know what type of compressor that was? Steve at Flagship insists the scroll compressors they used in mine are super quiet and have almost no electrical spike at start-up.

I've only used mine in heat mode since I installed the isolation transformers, but compared to just the blowers on the split system air handlers on our Commander, the new ones are very quiet. Not as quiet as the AC system in my house, but I believe that's related to higher air velocity from a smaller diameter of ducting and fewer outlets on the boat.

On our old Commander, the racket from the fan was absurd.

But back to the OP, I'd be surprised if the problem wasn't the Schrader valves.

 

[Sandiego]

Just as an FYI. I was quoted about $35k to replace all 4 split systems on my Hatteras 48LRC. I THINK this was using existing lines. It was mid pandemic but still probably reasonably valid. Here in San Diego. When the time comes I think I will go with self contained units. Much less expensive and easier to replace at the next cycle. Getting the water lines in place the first time will be a pain but preferable to dealing with copper refrigerant lines and potential leaks. My 1976 units are still working OK and we don't have extreme weather here so we don't really need it most of the time.

 

[jim rosenthal]

I recently asked the local CruiseAire dealer, who services the 1971 units on my Hatteras, about replacing them when they inevitably stop working. His advice was to keep them going as long as I could, and then replace the two units with one modern self-contained unit of about 20K BTU. He pointed out that no matter what I buy, it will not be made as well as the 1971 originals. Meanwhile, knock wood, the old ones just keep chugging along. s.

 

[Pascal]

Prices have been going up like crazy. Yesterday I replaced two Crusair chiller water air handlers on the 116 I run. I didn’t even bother asking my air con guy for a price from cruisair and instead got two 18k BTus from flagship. Last one I bought a year ago was $1100… now $1700. They said prices of raw material have gotten out of control and they had to raise prices.

That’s across the board…. Mach 5 fresh water pumps have gone up 50% as well… it s out of control.

 

[Chasemmc]

$4.99 for a dozen eggs. $7.99 lb for ground beef. $6.50 pint of heavy cream.

It's not over. Sort of happens every time you print money.

Had a retired HVAC guy recommended by one of my old timer doc mates. He came, charged the systems up, braised a couple of pin holes. Said if it holds then maybe stop leak to squeeze out a couple of more years.

I have been running heat only, but am getting a 30 degree delta from ambient. It's been a month, so far. He wants to see if they will hold for at least three months before doing more.

Fingers Crossed.

 

[q240z]

It's not over. Sort of happens every time you print money.

I don't mean to hijack the thread, but your comment reminded me of a funny thing I saw recently.

 

[No control]

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.

Hind sight is always 20/20, but what strikes me odd is that your HVAC guy didn't install new Schrader valves before charging it, and why he didn't add dye the first time he charged it to begin with. Schrader valves are the most common leak point and are cheap and easy to replace, so it's good wrenching to just do them while you're there and the system is discharged. Any HVAC guy worth his training would add dye every time they recharge if nothing else than to make their lives easier if they ever have to work on it again and is also a courtesy for the next guy that comes along.

 

[No control]

I don't mean to hijack the thread, but your comment reminded me of a funny thing I saw recently.
View attachment 64464

I recently got a fortune cookie with the fortune of, "If money doesn't grow on trees, where does it come from," and on the back was the FTX logo. I had a laugh about that because no... FTX is not where money comes from; it's where it goes to die.

Talk about marketing that didn't age well.

 

[Chasemmc]

I think he was trying to cost me the least amount of money until it could be established the units could be saved. Charged all 5 units, did some braising $400 including the gas. That's about how much it costs to fill my truck up with gas.....