All marine aircon needs sea water ?

[YARGESOL]

I'm planning to install additional aircon to cool aft cabins. I looked through Dometic DTU 16 Turbo and Webasto self contained S-16. But, they both need a seawater supply for cooling. I wonder if there are an options for isolated air condioners (like we have in the cars),with no raw water ? Residential split ,or window system is not an option. Roof mounted not as well. So, will still need water ?

[Cavalier]

Originally Posted by YARGESOL

I'm planning to install additional aircon to cool aft cabins. I looked through Dometic DTU 16 Turbo and Webasto self contained S-16. But, they both need a seawater supply for cooling. I wonder if there are an options for isolated air condioners (like we have in the cars),with no raw water ? Residential split ,or window system is not an option. Roof mounted not as well. So, will still need water ?

The compressors on automotive AirCons are typically engine driven, and the excess heat from the cabin is circulated out though the radiator in the engine compartment which is external to the cabin. The only way you'd be able to use an aor-cooled AirCon on a boat effectively would be to have the hot-side (condenser) linked to a radiator on the outside of the boat (ugly, leaks etc).

A typical marine AirCon exchanges the generated heat to seawater via a separate pump that draws in seawater through a strainer, runs through a heat exchanger (linked to the condenser) and ejects the [warmer] water over the side - above the waterline.

[a64pilot]

There are air to air heat exchanger Marine air conditioners, they are usually meant to be temporary and mount on a hatch, look like RV air conditioners.
Then there are some Marine air conditioners that are permanent, you see them sitting on the roofs of works boats etc. I suspicion that these are only Marine in that they have a sticker that says so, they often are split systems, and in my opinion are ugly a sin, that is why you only see them on work boats and not Yachts.
But beauty is in the eye of the beholder.
Issue is that you have to move a tremendous amount of air over the condenser, so that pretty much means external mounting on smaller boats, and it’s tough to make that not detract from the appearance.

[YARGESOL]

Cool, clear. So, will not avoid another water intake... Or, can I add a T-hose after the strainer, instead of drilling another through-hull and, engage another pump ? Could they supply enough water for both AC (no.1 is Flagship 16kBTU and a March LC-3CPMD pump water to him). Or, the 2-nd (say Webasto pump) will conflict with March ?Hoses are 3/4''

[Outlaw7]

I am glad you took my advice and are looking at adding more AC to the boat.
Your current pump will hand another unit upto 12,000 BTu. Two pumps should never share the same thruhull, a sea chest yes. Why not another Flagship, I am sure that as a current owner they will give you good discount.

[a64pilot]

Many people run multiple AC’s off of one big pump. I think that is more common than multiple pumps off of one strainer. Me, I’d likely go with multiple pumps so that if one broke, I only lose one AC, although changing pumps isn’t tough as long as you carry a spare.

Some people will T in their AC system pump with the main engine thru hull, although many advise against it.
Best in my opinion is a thru hull and strainer for each user, although when I installed my Watermaker I connected my generator and main engine to the same thru hull and it has worked fine.
More thru hulls are of course more places that could sink the boat, so think of that too.

[Attikos]

A neighbor of mine in the marina installed a military helicopter A/C unit he got from military surplus before it was scrapped. He says it works well for him. It's mounted on deck on what was a hatch, though, which you say you don't want to do.

[YARGESOL]

Originally Posted by Outlaw7

I am glad you took my advice and are looking at adding more AC to the boat.
Your current pump will hand another unit upto 12,000 BTu. Two pumps should never share the same thruhull, a sea chest yes. Why not another Flagship, I am sure that as a current owner they will give you good discount.

I just spoke to Tom from Flagship... I have to fix the existing unit first. If the logistic shipping to Europe will be reasonable, I shall ask them to quote the 2-nd unit. But, my Flagship is not a quite guy... Studied A64Pilot thread and,folks saying Webasto/Dometic are super quite (even located under bank). They have dealers everywhere (thought considered through out...after certaine period).
And,I shall apply either 3M PRestige film on all Plexiglass windows,or Hanitacoating SolarZoneXTRM PolyZoneSkylite to reduce heat.
Thank you,Outlaw7

[YARGESOL]

A64Pilot:"More thru hulls are of course more places that could sink the boat, so think of that too."

On both hulls I've got already a dozen of them... and all gonna be cleane & taken care of.
Sure, that is better to have separate water supply to each user

[a64pilot]

I have a webasto mounted under my bunk.
All you can hear is the air coming out of the vent, if you listen well, you can hear a slight buzz from that same vent when the compressor is on, but you have to listen hard as it’s just barely audible.
The air however isn’t quiet as there is a lot of it, more registers would help that, but it’s not bad.
Webasto is also among the least expensive units, I bought mine based on cost, figuring I would just replace them as necessary as opposed to trying to repair, but they have run perfectly for three years so far.

[captstu]

I have an RV in it. Works well. Quiet. No water. Don’t know what I missing?

[YARGESOL]

Compressor on my Flagship I could hear from outside of the boat. But,I've just got to know...this is 18500BTU unit...that's why my small Panda can hardly and rarely start it.

[boatpoker]

Originally Posted by YARGESOL

Compressor on my Flagship I could hear from outside of the boat. But,I've just got to know...this is 18500BTU unit...that's why my small Panda can hardly and rarely start it.

Something wrong with your compressor. My last boat had a flagship unit for 20yrs and the only thing I heard was fairly quiet air movement. I was so pleased with that unit that I installed one in my new boat three years ago. The air movement was quite loud until I got my ducting sorted out but is now pretty quiet.

[a64pilot]

I have a 16K BTU Webasto and a 6K.
The 16 is a hard start, put a hard start cap on it and it helped a little.
The 6 K is easy to start, both are quiet. There is a bigger Webasto and I am pretty sure it has a hard start kit included and is easier to start than their 16 K. It may be a 24K, but not sure. I briefly considered it, but don’t need that much cooling.

[Squanderbucks]

I have two A/C units working off a single thru hull but it is not just a "T" in the hose. Tried that - doesn't work as intended. When running one A/C it will draw air from the one turned off and siphon air into the lines of the one working.

What I settled with is this: One thru hull and strainer, "T" after the strainer , near the secondary unit pump and each A/C has it's own pump I put a one way bronze flapper valve in the hose to the secondary units pump. That way when it is off and the main one is running the siphon is stopped.

I never run the secondary only or I guess I would need another one way flapper valve.