Marine Air Condtioner - Cost to Install?

[bobfnbw]

Just looked at your diagram. I agree that that would not be a good install. The duct line while is long, also has to many bends.
In looking at your boat, seems to me that the best way would be a hatch a/c unit on the foreward over head hatch. But you said you have the gear already, so my next thought is the port locker foreward of the settee. have one duct go foreward to the vberth and on aft to the aft side of the settee. Use a couple of hella fans to move the cold air around. one return duct in the locker door. One thru hull in the locker with a foreward facing scoop, and a d/c line in the hull with a vented loop. You loose a locker. But I would rather loose the locker than the engine compartment.
Bob

[jkleins]

Originally Posted by bobfnbw

If you have a dry boat, then keep it that way. If you do not, then find out how to get it so.
Bob

Is this really possible? I have never seen a boat with a deep bilge in the keel like most full keel boats are built that didn't have a little water in the deep bilge from the stuffing box, changing the speed sensor in and out or dripping from the forepeak anchor locker. How are people handling this water intrusion that seems to me to be inevitable. I put a small bilge pump in with a check valve to try to get as much out as possible but to get it dry seems like quite a challenge.

Thanks,

Jim

[stevensc]

There are lots of sailboats along the Gulf Coast Houston New Orleans and Panhandle of FL maybe you can fine an Ericson 27, or similar, owner who has a/c installed to find out how where and how much$. Maybe the Ericson Manufacturer will have some Ideas. I agree it will be very uncomfortable to liveaboard during Louisiana summers without A/C
Good luck
Steve

[Sailmonkey]

Sorry, just re-read the original post........Since you've got the unit already, you're going to have to be creative and fit it in the hanging locker. Any attempt to make the duct as long as you've shown will be bad things. And there's no need to put a vented loop on the discharge, the system is sealed. As an other aside, avoid the scoop in you waters. These things breed sealife clogs on ac intake lines.

[Target9000]

Originally Posted by Sailmonkey

Sorry, just re-read the original post........Since you've got the unit already, you're going to have to be creative and fit it in the hanging locker. Any attempt to make the duct as long as you've shown will be bad things. And there's no need to put a vented loop on the discharge, the system is sealed. As an other aside, avoid the scoop in you waters. These things breed sealife clogs on ac intake lines.

This boat doesnt have a shower but it does have two sinks. Maybe there is a gray water tank associated with those that we can use to drain the condensation tray.

Ok, So will it matter that the discharge vents will be close to the intake vent? I read earlier that you should make the duct work runs as long as possible to avoid recycling the cold right back in the A/C.

We had thought about putting the AC in the hanging locker but kinda didnt want to lose that space for clothes. I suppose if the A/C was in the bottom of the locker she could still use the top for clothes unless the unit would produce condensation.

I was under the impression the A/C unit had to be above the water line? If we put it in any of the setees it will be below the water line.

I have attached a few pics of the inside of the boat so it would show better what ya'll are discussing.

So the duct work should be insulated to prevent condensation huh? we bought them from the manufacturer of the AC so hopefully they are, if not they were cheap and we can buy different ones.

Your advice on this stuff is super super helpful, thanks again for taking the time to help me in getting my moms liveaboard Ericson comfy and ready to move on

[Sailmonkey]

If there's room under the V berth, you could also put the unit there and duct accordingly.
There is no need to place the unit above the water line, the only thing you need to do is keep a constant uphill direction from the seawater pump to the unit, this'll prevent air lock on the pump.
For condensate I've always installed a condensate drain pump in the bilge (when there's room)
Pump, Condensate, 115 V - Condensate Pumps - Condensate - Pumps : Grainger Industrial Supply
These can either be wired to seperate breaker, or straight to the unit through a pop-up breaker.

The problem with excessivly long duct like you've drawn is the airflow creates more friction than the blower can overcome and keep the volume of air needed to allow the unit to operate properly. The only problems I've seen with the discharge being too close to the inlet is when the unit was intsalled in a hanging locker with the only vent out below the inlet and facing up.......go figure. If you discharge out the top of the locker and vent aft with the inlet screen on the face of the locker you will not have any issues.

[GordMay]

You can use the nearest sink drain, for the condensate. Make certain that the condensate drain hose slopes continually down, without any valleys. You don’t need a grey water tank.

Yes, it matters if the cold air Supply-Air vents are too near the return air. This would cause the short circuiting you fear.
Notwithstanding, the longer, and more bends in the S/A duct, the greater the frictional resistance (a bad thing). The corrugated round duct, typically used on yachts, also increases resistance.
The trick is to use as large diameter duct as practicable, smooth bore if possible, and to compromise on length. Obviously, you don’t want the S/A directly facing nor adjacent to the R/A.

I don’t know why the A/C unit must be above the waterline.

[Target9000]

ok all that sounds great. I have attached another drawing that mounts the A/C to the top of the underside of the setee next to the head and the pump underneath it. The one duct can run into the head and have an aft vent in the head wall. the other duct can run through the locker in the head and into the vberth area.

Im thinking this might be a good way to try and preserve the hanging locker for clothes and it would put it close to the sink drain where we could route the condensation from the drip pan.

Also there is a drawer in this setee that could be replaced with a vent making the destruction a little easier.

Any ideas on this drawing or any other ideas that dont include the locker?

[Sailmonkey]

Condensation through a sink drain will only work if the unit is above the heeled waterline......not possible in a locker....not possible in the vast majority of sailboats.
I'd also not discount the possibilty of installing the unit under the V berth, running a 4" duct into the head vanity, tee off a 2" to the v berth (you'll need to build some sort of attractive enclosure in the fwd corner of the head), then vent the main line out behind the settee below the black fan in the picture.
the noise from the pump is normally the most irritating so I'd put that under the galley sink or under/near the engine. The water overboard could then be put in the bootstripe under the head sink.

[Target9000]

Ok,
I like the idea of putting it under the vberth. Would it matter to have the pump so far away from the unit? To put the unit under the vberth and the pump by the galley is a pretty far run especially if it is to be all uphill.

as far as the condensation tray is it possible to add a small pump to pump the water out into the sink drain if an downhill direction isnt possible (probably isnt).

[Pblais]

Would it matter to have the pump so far away from the unit?

The problem with long water lines is the sea water tends to grow stuff in the line. You really want the shortest runs possible. Make that a priority. An extra through hull is better than a long run. Mine is located far forward and shares the through hull with the raw water wash down. Just be sure you have good access to the unit and don't block the air intake to the blower. A long line on the condensate is a fair trade off.

Some installs use a pitot tube to allow the flowing discharge water to suck the condensate out the discharge above the water line. You need to watch them and clean them but they work. They can clog from dirt in the air.

[Sailmonkey]

I've installed several with this long run, but the hose is expensive. you can install the pump in the head and tee into the head intake. I've also relocated some pumps for people who didn't like the noise from the pump. Cal pumps are quieter than march but don't last anywhere near as long.
If you look at one of my previous posts you'll see a link to a condensate drain pump, essentially a shower drain pump, but dedicated to the A/C.

[Target9000]

Ok i like those ideas. We just looked at pictures of openings of the boats storage. There are pretty small compared to the AC and im afraid we may not be able to get it in the openings as is. i think the ac may be too big for the hanging locker as well.

Its 11" high x 14" x 15" base.

One idea we are toying with is putting the AC in the head where the porti potty would sit. We could build an insulated box with an intake vent, put an intake vent in the door and route the duct work into the Vberth and into the salon.

My mom doesnt ever use the porti potty and only has it on board for regulations. We are thinking this might be a great spot as it requires minimal destruction.

Thoughts?

[Sailmonkey]

You'll be better off with a more "permanent" install than with something just set somewhere. Actually, if you're handy with cabinetry you could even put the unit on top of the hanging locker and build an extension of the locker around it.
I'd be willing to bet the unit will fit under the V berth, you may need to cut an access panel though. I've put some huge A/C units into some very cramped holes, but the install costs were up there as the installs took up to a week.
as an aside, if you remove the porta-potty where do you go when the boat isn't tied to the dock?

[Target9000]

Yes we will look under the vberth.. We'd have to cut a hole into it though in order to install it but that might work because we would have to put a vent for it in the vberth as well. Perhaps we could build something to put the unit above the hanging locker but does it matter it would be so high up away from the pump?
the box we were thinking of building using would be made permanent to the head floor. We put a vent in the box and a vent in the door for the intake air. We could rig it where the porti potty would sit on top of it if we went out and needed to use it. and when the boat is at the dock (90% of the time) the potty would be stowed away and the AC box could make a nice seat to sit and do makeup/hair etc in the head.

If we built the box in the head im not sure how we would run the duct work into the salon. there will have to be at least a 90 degree turn in the duct work to get there (which isnt really a big deal if its only about 14% less efficiency).

Running the duct work into the Vberth would be easy cause we could just run it up the the corner of the head and cut a hole for the vent on the forward side of the head wall (the vberth wall). We would just hide the exposed running duct work.

As for running the duct into the salon..maybe we could run it up the corner of the head as well and across the ceiling out to the aft head wall (the salon wall) where we'd put a vent.

Having the box in the head would allow for downhill condensation drainage into the sink drain.

Im not sure if this is the best way but I like that it saves the traditional storage areas and makes use of the amount of space in the head.

Is there a better reason for putting it on top of the storage locker or in the Vberth?

I have a attached a rough drawing of where the box would sit and the duct work. Im not sure about where to put the pump but if its noisy then further away is beter although i worry about things growing in it as was said earlier.

Thanks again all your help is so appreciated- I will keep you updated as we get the boat and what direction we will take, we'll definitely take all options under consideration.