Novice air cond question

[a64pilot]

I was curious about the AC with Alternator / inverter thing so I gave it a shot today. I just finished installing my whisker pole and wanted to give this DDW thing a try, so I motored about 5 miles or so upwind.
What happened on my boat was the batteries discharged until the alternator saw a low enough voltage that it went to absorb, once in absorb it would carry the load, barely. So it seems at least with mine, you can run the AC off the Alternator.
Has to be hard on the alternator though I would think.


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[Emmalina]

Acclimatize ! Think my ac,s are dead as we never use them. Not worth the noise or hastle and the expense... Fans are as effective for us !

[valhalla360]

No free lunch. A huge battery bank with a charging system to feed it, inverter to pull the power out and fuel to keep it going, is likely going to be more expensive than just installing a generator and keeping things simple.

Also don't forget that huge battery bank will wear out after a period of time if you are running it completely down regularly, so that will eat up what little fuel savings you can come up with.

A built in generator is nicer but since we spend most of our time in marinas, our yamaha2400 does a nice job when at anchor.

As far as the idea of just "surviving" without, no thanks. We aren't out to prove we can "survive". Cruising is meant to be an enjoyable experience for us and we've been in far too many calm muggy anchorages to put up with that.

[mausgras]

I've been looking at the RV style roof top AC. Fits nicely over the saloon hatch, nice low profile so it does not obstruct the boom vang or any lines. But have not got up to power requirements yet.
Do these things only run off an external power or the vehicle battery/alternator?

[valhalla360]

Originally Posted by mausgras

I've been looking at the RV style roof top AC. Fits nicely over the saloon hatch, nice low profile so it does not obstruct the boom vang or any lines. But have not got up to power requirements yet.
Do these things only run off an external power or the vehicle battery/alternator?

If you are certain nothing is likely to catch on them on you have a flat section of deck, they are a nice option as it eliminates the complications that come with water cooled marine units.

But they won't solve the power requirement issue. They typically come in 13.5k or 15k btu units and the power consumption is similar to a similar sized marine unit.

[Sailmonkey]

Originally Posted by mausgras

I've been looking at the RV style roof top AC. Fits nicely over the saloon hatch, nice low profile so it does not obstruct the boom vang or any lines. But have not got up to power requirements yet.
Do these things only run off an external power or the vehicle battery/alternator?

Shore power only. And they're not saltwater resistant at all.



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[Sailmonkey]

Originally Posted by RichandHelen

You gotta be kidding...

About what?


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[a64pilot]

Originally Posted by mausgras

I've been looking at the RV style roof top AC. Fits nicely over the saloon hatch, nice low profile so it does not obstruct the boom vang or any lines. But have not got up to power requirements yet.
Do these things only run off an external power or the vehicle battery/alternator?

There is a Marine version, which I believe is about the same. They run off of AC, and I think other than expense there is no advantage.


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[valhalla360]

Originally Posted by Sailmonkey

Shore power only. And they're not saltwater resistant at all.



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If you are talking about taking wave over the top of the unit, probably true. The ones I've seen on boat are typically mounted at the highest point on the cabin to largely negate this issue.

If it's just the salt air, the RV's that stay in beach locations do fine.

[Sailmonkey]

Originally Posted by valhalla360

If you are talking about taking wave over the top of the unit, probably true. The ones I've seen on boat are typically mounted at the highest point on the cabin to largely negate this issue.



If it's just the salt air, the RV's that stay in beach locations do fine.

I think that depends on beach location. They go to s@$t pretty quickly on Galveston island, 2-3 years before they're really problematic.


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[valhalla360]

Originally Posted by Sailmonkey

I think that depends on beach location. They go to s@$t pretty quickly on Galveston island, 2-3 years before they're really problematic.


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We spent significant time with the RV in a number of coastal locations including Port Aransas (just south of Galveston). Our 1997 unit is still fine and haven't heard of others complaining about problems.

If we had a power boat (no boom or lines to snag on it), I'd switch in a heartbeat.

[skipmac]

Originally Posted by RichandHelen

You gotta be kidding...

Based on several years living aboard in the Bahamas and Caribbean I would agree with the 98% comfortable at anchor statement and I do like my comfort and that includes staying cool.

Then there's the 2% of the time when I would trade half interest in my boat for a bit of air conditioning. One of those nights when it's hot, muggy, no breeze at all and then the bugs attack. Leave the hatches open and you're eaten alive by mosquitoes or noseeums or both. Close the hatches and you risk heat stroke.

At the dock in a marina is a whole different story.