A/C Issues Self-contained vs Conventional

[Angela]

Gee, I feel like such a pioneer now. When I first started contemplating this conversion a few years ago, I was met with a number of negative comments about how a boat the size of mine has no business having self contained AC units anywhere and that it was wrong, but for no other reason that "that's just wrong," and now some of those very ones are considering self-contained for themselves. Huh....I guess it wasn't such a crackpot idea after all.

Anyone ever put a self contained unit under the flybridge helm? My saloon air handler is located there since the FB is on top of the saloon. To convert to self contained, I'd have to run seawater lines up there. There's not a lot of space to get the lines up there. Just about all the space is taken up with wiring, steering hydraulics, and shift/throttle cables.

I have a neighbor with a Hatt that I think is a 50C. His galley/salon AC was set up like that by Hatteras. I looked at his. I think that is how I will do my pilothouse AC that now needs to be replaced and I can't find a 16K unit small enough to fit in the cabinetry that houses the old air handler. I'll get new headliner and overhead lights "while I'm in there." I think the toughest part will be finding room in the chases to get the water lines up there, and remember, the condensation hose has to come back down too. Or you can do what Mario did: http://www.samsmarine.com/forums/sh...urists-should-cover-their-e&highlight=purists That thing is still running strong for him!

Mario helped a friend install a self-contained marine AC unit under a flybridge helm, and he advised me that they had no trouble pumping water up there with a dedicated March pump - not the smallest one, but the next size up. So far, I've got water pumping up to a unit that sits about even with the bottom of the PH windshield.

 

[Angela]

On a related topic, I heard the other day that AC manufacturers are no longer recommending an inside strainer on seawater intakes. Anyone know anything about this? I still have one, with no plans to change it.

Were they offering 24-hour emergency dive services too? LOL Although I don't have any concrete facts or experience to base my suspicions upon, at this time, I just don't trust exterior strainers to keep out all of the crud. While I trust them on my engines, the boat is usually moving when the engines are running and those strainers are in play, and I suspect that with the boat on the move, that helps brush off anything that would tend to get sucked up against the screen and held there. AC pumps, on the other hand, spend a lot of time running with the boat sitting still. I've seen how bad my internal strainer can get packed with seagrass and crap. I sure would hate to have to get up in the night (or day) to take a swim to clean off a clogged strainer screen in order to get the cooling resumed. If anyone has those external strainers on your AC pump, I'd like to hear from you as to what your experiences are in this regard.

 

[Pascal]

I had external strainers installed on charmer last July and while we ve kept the internal strainers I haven't found anything in them since. Looks like whatever gets stuck against the screen releases when the pump cycles off.

And as you know, weeds are a serious problem here at Monty's!

 

[omecojh]

I installed a self contained 16btu in the saloon of my 42 sportfish last summer. Used same water pump, ran hoses across beam of boat and up a couple of feet. very happy with results.

Would consider the self contained unit if I have to replace the unit that feeds th two staterooms but would be more difficult.

Unit is Marine Air but now owned by another compaqny.

 

[jim rosenthal]

What is the maximum vertical distance that the March pumps, or their equivalents, can push water up to a marine AC unit? My ACs are working fine, but they will not last forever and I am thinking about what to do when they finally give up the ghost. Two self-contained units (6-7K and 12-16K) would replace the two split systems I have now. I think the SC units would probably fit in the spaces currently occupied by just the airhandlers for the split systems, or close to it. The only problem is piping the water flow around the boat, and up to the units. Hence the question about vertical flow of water under pressure from the AC seawater pump.

 

[Pascal]

The flow vs head numbers are provided on the pump spec sheets I don't have one handy but they can be found on the manufacturer sites. Flow goes rate goes down obviously but it s doable

 

[34Hatt]

Gee, I feel like such a pioneer now. When I first started contemplating this conversion a few years ago, I was met with a number of negative comments about how a boat the size of mine has no business having self contained AC units anywhere and that it was wrong, but for no other reason that "that's just wrong," and now some of those very ones are considering self-contained for themselves. Huh....I guess it wasn't such a crackpot idea after all.

Get use to it the longer your here the more it happens. I was told years ago a computer won't work on a bridge, External strainers won't work and some that didn't believe me when I was the first to tell them about E10 eating up the fiberglass tanks

And for the external strainers on A.C after about 8 years of no problems only once did I have a problem the jelly fish where so thick there was thousand of them. I used a scrub brush on a extension handle in the dinghy 5 mins later all Good!

 

[Avenger]

What is the maximum vertical distance that the March pumps, or their equivalents, can push water up to a marine AC unit? My ACs are working fine, but they will not last forever and I am thinking about what to do when they finally give up the ghost. Two self-contained units (6-7K and 12-16K) would replace the two split systems I have now. I think the SC units would probably fit in the spaces currently occupied by just the airhandlers for the split systems, or close to it. The only problem is piping the water flow around the boat, and up to the units. Hence the question about vertical flow of water under pressure from the AC seawater pump.

If you're going to self-contained you might as well install a single unit in place of the current salon A/C and just run a duct through the head up to the stateroom. Unless you're bent on keeping the door shut you could eliminate an entire unit.

Just a thought.

 

[captddis]

After you install your selfcontained units, you will want to save a old shift cable for rodding the 100+ feet of hose that has totally plugged up with barnacles. Having an acid pump helps too.
Tomorrow I go to a Carver who's units are shutting down on high pressure and flow is a trickle. It will be a joy lugging acid through the boat and running the cable back and forth.

Last year I spent 4 days on a sea ray trying to restore flow and replacing a unit that died an early death from lack of cooling.

 

[Angela]

After you install your selfcontained units, you will want to save a old shift cable for rodding the 100+ feet of hose that has totally plugged up with barnacles. Having an acid pump helps too.
Tomorrow I go to a Carver who's units are shutting down on high pressure and flow is a trickle. It will be a joy lugging acid through the boat and running the cable back and forth.

Last year I spent 4 days on a sea ray trying to restore flow and replacing a unit that died an early death from lack of cooling.

Wow, that would really suck to have the hoses clog with barnacles to the point of having to snake them. I think at that point, I'd almost consider pulling a new hose if the acid didn't bust it up. I have the pump in a covered bucket gig that use a couple of times a year to clean my stuff. Fortunately, I’ve never had to snake a hose. Maybe I’m just cleaning often enough, since I’d be the one to have to deal with my own neglect, not to let it get that bad...I don’t know...

I was also very fortunate to have access to existing unused through-hulls/strainers so that my runs aren’t that long, too. Admittedly, not everyone will have that advantage.

 

[Boatsb]

After you install your selfcontained units, you will want to save a old shift cable for rodding the 100+ feet of hose that has totally plugged up with barnacles. Having an acid pump helps too.
Tomorrow I go to a Carver who's units are shutting down on high pressure and flow is a trickle. It will be a joy lugging acid through the boat and running the cable back and forth.

Last year I spent 4 days on a sea ray trying to restore flow and replacing a unit that died an early death from lack of cooling.

That's why the self contained units are cheaper. The make more because the don't last as long.

And remember Steve also stated the water lines on them are problematic. Too bad no one owning them here seems to find that a problem but customers seem to pay more to keep them running.

 

[captddis]

Wow, that would really suck to have the hoses clog with barnacles to the point of having to snake them. I think at that point, I'd almost consider pulling a new hose if the acid didn't bust it up. I have the pump in a covered bucket gig that use a couple of times a year to clean my stuff. Fortunately, I’ve never had to snake a hose. Maybe I’m just cleaning often enough, since I’d be the one to have to deal with my own neglect, not to let it get that bad...I don’t know...

I was also very fortunate to have access to existing unused through-hulls/strainers so that my runs aren’t that long, too. Admittedly, not everyone will have that advantage.

But you would run the hoses to where they are accessable. Not so with many of the others. I had a triple decker Carver that I think had a kinked hose.I think because it was run where it was almost impossible to get to. Run along the hull with vinyl over it. I HATE those hard white hoses that everyone uses! Don't seal well and the barnacles LOVE them.
Anyway after countless attempts to get it clear, I ran a new black hd heater hose all the way to the front SR. 8 hours total!!! Many areas were not accessable.

This after moving clothes, shoes chairs shams pillows more pillows carpets..............
Remember with a self contained unit, You or a tech needs to be working on the unit in 100 degree heat sweating and dripping all over while working on it.
I much prefer the split system with most of the servicable equipment in the ER.

 

[oldawg]

Now we are getting to what I wanted to hear. So if I choose to go self-contained, I should try and make my hose runs as short and accessable as I can. I know there was some recent discussion on this but does anyone know if the compressor can be replaced on an old 5,000BTU Lunaire unit? I would try to get details but the boat is presently about 200 miles away.

 

[MikeP]

"That's why the self contained units are cheaper. The make more because the don't last as long.

And remember Steve also stated the water lines on them are problematic. Too bad no one owning them here seems to find that a problem but customers seem to pay more to keep them running."

But this is a function of poor installation, not poor quality components. Long water feed/return lines are because the installer chose not to install a new sea hull close to the unit. Some people can screw up an anvil; some of them work on boats; some of them build boats.

"Too bad no one owning them here seems to find that a problem but customers seem to pay more to keep them running."

I would say it a GOOD thing that no one owning them here seems to find it a problem! It indicates they were installed properly.

 

[jim rosenthal]

This is really useful information, though. One of the reasons I hesitated to just go ahead and replace my (working) split systems with SC units is that I didn't want seawater piped all over the boat- as in where I couldn't get to it if it started to leak and flood the bilges. I think if/when I do this changeover, I am going to install a pump for each unit and as close to the unit as I can, keeping in mind that they will need service of SOME kind sooner or later. Which means no long runs of seawater hose or piping back and forth.

More or less on this topic- when replacing split systems, can the old copper lines be kept if the original compressors have not broken down? I have heard it both ways.

 

[34Hatt]

Now we are getting to what I wanted to hear. So if I choose to go self-contained, I should try and make my hose runs as short and accessable as I can. I know there was some recent discussion on this but does anyone know if the compressor can be replaced on an old 5,000BTU Lunaire unit? I would try to get details but the boat is presently about 200 miles away.

Yes this also supports when Angela and I both said separate pumps less hose and you can see how much flow is coming out each unit. That is what I don't like about two units on one pump I had even talked to Steve about this he said my setup was fine but yet I still had problem with the forward unit. If it flows through both no way to know unless you start blocking and plugging hoses PITA.

Question is is it worth changing a compressor most times it costs close to replacement cost!
For example compressor burned up on a old Marine Air 16K was looking at 1,200 min for A.C shop to fix it, could go to 1,500 on a 15 year old unit or buy new with warranty for 1,700. I got it done 2 weeks faster as it was the end of July and I would have been with out the a.c on my 10 day trip. Now I have a newer quieter unit with gauges so I don't need an a.c tech to check the charge or gauge set. That is $150 saving minimum since that what they charge just to come to the boat. Which I don't mind I understand the time to travel but when they charge two boat the same in the same marina on the same day
At the same time the same A.C shop replaced a compressor on a friends boat split system about 18 years old price was over 3K

 

[Pascal]

This is really useful information, though. One of the reasons I hesitated to just go ahead and replace my (working) split systems with SC units is that I didn't want seawater piped all over the boat- as in where I couldn't get to it if it started to leak and flood the bilges. I think if/when I do this changeover, I am going to install a pump for each unit and as close to the unit as I can, keeping in mind that they will need service of SOME kind sooner or later. Which means no long runs of seawater hose or piping back and forth.

More or less on this topic- when replacing split systems, can the old copper lines be kept if the original compressors have not broken down? I have heard it both ways.

When is the last time anyone has seen an air con water hose fail? Talking about the hose, not the clamps, fitting etc.... Air con pumps put out flow, not pressure...


When a new compressor or condensor is installed copper lines are vacuumed out before charging so there is no need to replace the lines.

I wish the cost of a new condensor was that close to replacing a compressor... I just had a 48k btu compressor replaced for $1800 whereas a new condensor lists for $5k...

I am seriously considering putting two of the self contained with gauges and soundshield in the saloon on m 53. The forward split pops the breaker (likely the compressor on the 10 year old condensor) and the aft split cools but cycles on and off when pushed hard (thermal safety in the compressor). As much as I wasn't too keen on self contained, I m tired of spending so much on the splits.

 

[jim rosenthal]

I have not seen the seawater supply hose fail, but the total length of the seawater supply on my two split units is maybe three feet- both compressor units are located in the engine room right above the seawater inlet and strainer and pump. The output of the pump is divided to supply both compressor chassis. The whole setup is very compact. Literally there isn't three feet of hose in total, I don't think.

If I adapted this setup to a split system, I would have one run of seven feet or so over to a unit in the salon, which isn't too bad, but then I would have another run of fifteen feet or more up to the forward stateroom, with a new discharge through-hull up there. And that seawater supply would have to run behind the galley etc. (along the same route that the copper lines now take). I would secure the hose as frequently as I could but I would still worry about chafing etc back there where I can't easily get to it. If the copper tubing would leak (which it never has) I would lose the Freon. If a seawater hose leaked back there I could lose the boat.

This will take some thinking. I hope neither of the current units decides to crap out in the near future.

 

[Avenger]

So no-go on the idea of running a duct from a single self-contained up to the fwd stateroom?

Much simpler and cheaper that way.

 

[MikeP]

Or you could add another thru-hull/pump for the second unit mounted close to the unit.

If you use multiple pumps/separates, the advantage is you have multiple, independent units that do not depend on once single component (pump/relay box). Obviously, the disadvantage is that you need a thru-hull and pump for each unit.

Our cross-dock neighbor has a separate ac unit/pump for the aft deck area of his 58 (hard enclosure). He often remarks at how much less trouble it is (none) compared to the oem Hatt units.

I will have to say that in our case (53MY) the separates that I have seen at boat shows in the last year or two would be quieter in any stateroom than the existing oem units. Based on personal experience, the compressor noise in the ER makes the guest SR almost unusable for adults due to the random cycling noise of the various units. Teens have no trouble.