Can anyone help recommed a marine a/c unit - size and brand?

Check out the Dometic Marine Air Systems website. These are factory installed by Formula. Lots of information, literature, and installation/maintenance manuals printable from website.

Try Mermaid units. I put one in myself - very small - works great!

John,

You may want to investigate CruiseAir units. Depending on the size of the boat they make several units and they are very simple to install without buying extra parts. I have done two recently with no problems and it's not rocket science. As I recall the last one was a bit over $1K and it cools a 43 Scarab very well in 90+ degree heat. Any questions just give a yell.

Thanks, Karl

I looked at the CruiseAir and the Mermaid. It would be for a 42 fountain, so I am thinking a low output model 5-7K BTU.

You might want to ask around about that. I wouldnt go less than 12K for a boat that big where you live.

12K - that seems like a big unit. The guy at mermaid told me to find the volume of the cabin then multiply that by 14 and go with the unit just under that value. I guestimated 371 cubic feet. Does that sound close?

That cubic feet seems really small for a 42. I have a 30 and figured 810 cubic feet for the cabin. Actually size-wise, 5K to 12K they arent much different. The 12K runs on standard 110 shorepower too. Those numbers that mermaid gave you are correct for cruisers with good insulation that sit at the dock with the ac running all the time. For what we do, run the boat, stop somewhere, want to cool it down quick, which means getting all the humidity out first, I think the bigger units do a better job. But then again, I like my cabin around 65 when Im sleeping. Theres a couple good ac guys on here, Im sure they will chime in too.

Smaller unit will get humidity out better cause it has longer compressor runtimes.
Larger unit will cool faster but the more frequent cycling will allow the humidity to remain higher and will "feel" warmer.

Several mfrs offer sizing guidelines. My advice is to use them. Once you arrive at the "correct size" you can adjust up or down one order of magnitude for personal preference, but bigger isnt always better unless you plan to leave the cabin door open all the time. In that case, go with the big one,.

I just installed a 16,000 Ocean Breeze in my 42' Harley. The cabin is a little bigger than a Fountain. It works fine as long as you keep the door shut. But I would not recomend anything smaller, especially in your neck of the woods. I hear it gets hot down thar in Texas!

Steve Hixson