I have been struggling with this cooling issue too since living here in "Hotlanta", which makes for very uncomfortable hot days and nights on Lake Lanier in the summer. We got rid of our 9,000 btu stand up (Heier) unit that had the single hose vent system. Even with the vent hose insulated, it still was hot down below once the sun came up.
I recall spending a few nights onboard a friends Hinter 34 in Tampa, Florida. He let us use the v-berth and had one of those Cruise-n-carry portable AC units that fit in the front hatch. I believe it produced about 5-6K btus. At the marina the unit was fantastic for chilling the v-berth to get a good nights sleep at the marina. Soooo, where did these units go? You can only find them used! Enter the new unit on the market made by Pompanette and sold at West Marine. I do not know how great these units are, but they advertise them giving off 6,000 btus, are the same in shape and design as the Cruise-n-carry and cost about $1200.00.
Touch choice given that for an extra thousand you can have a decent 16,000 btu central system installed. All we want is a good nights comfortable evening below this summer. I keep thinking about that portable unit my friend had in the forward hatch. It was perfect for the night. Its something we are considering.
I am not a spokesperson for West Marine nor this AC company!!!!!!! Its just nice to see someone came back into the hatch mounted AC cooling game.
Bob
'88 Mark II
Hotlanta