Evaporative AC on a boat

[shipwreck66]

I'm probably just installing a big fan w/ a holding tank but the "hope" is that when the bob-and-burn days of 100 degree summer arrive this might provide relief. And with a 1 amp current draw it will easily run on battery while away from dock. I will fill water tank with ice to start with. Any insight or suggestions?:neutral:

 

[Joe Diver]

I wouldn't bother with a swamp cooler. They don't work well in mid to high humidity areas. You need to be in a fairly arid area, or have very low humidity for them to work well.

If you must have AC, and I live in NRH, my boat is out on Eagle Mountain, so I understand....a refrigerated air unit is a must...either a stand alone inside the boat, or a very small window unit rigged to the forward hatch.....is what I would do...but it must be refrigerated and dehumidifying.

 

[shipwreck66]

Joe, I thought I'd get your attention on this one. I do have a window unit for the forward hatch while at dock, works awesome. My fairytale hope is for some relief while my spouse and I are actually out on the lake under battery power in June-September. I'm hoping to fill with ice before we head out even if it only lasts a few hours. The itsy bitsy thing I got at Cabelas actually works, for about 45 minutes, then the ice is gone and all you have left is a fan that spits at you. I'm also in NRH, just docking east now.

 

[Joe Diver]

I have a friend with a Catalina 36 out on Grapevine. He's at Scott's and is the person who got me into sailing....

The only solution that works well and lasts is refrigerated air. The Texas heat is just too much for anything else. You could get a smallish generator, put it in the cockpit, and use it to power the AC unit while away from shore power. Those AC units draw some serious amps, and even if you invested in a high dollar 8D batteries to get huge amp hour banks and a wicked inverter, you'd still probably be better off going the generator route. Modern portable generators are getting smaller, more quiet with higher output all the time.

 

[philwsailz]

The only other thing I have seen work well is an ice/ice-water-powered air chiller where a closed loop of antifreeze moves from basically a very large ice chest to an automotive heater core. There is a coil of copper pipe in the ice chest connected to the heater core via insulated flexible hose and a 12v pump. A 12v squirrel fan blows air through the re-purposed heater core. In this system the air is colled sufficiently to achieve dehumidification so a condenstation pan and drain are requried.

I have seen this system installed in an aluminum outboard-powered cruiser owned by an acquaintance. He claims he can keep ice for a weekend with his chiller, with "sodas" kept cool in the ice chest too. I can attest to the fact that the air coming out of the unit is quite cool and the boat interior is comfortable, even cold. He has insulated the boat interior and upholstered it, (he is an old hippy van converter) which no doubt improves his ice life, but know it works.

This system still depends on a compressor, except the compressor resides in the freezer that made the ice.... Other than that, with ice as the cold source instead of an evaporating gas, (freon or newer equivalent), the system functions identically to an air conditioner. The down-side is that the chilling capability is directly corrrelated to the amount of ice you can bring aboard...

Something to consider if you have a rarely used large empty void somewhere on the boat...

 

[shipwreck66]

Phil, I will probably try the idea you are describing. We used one of those little units from Cabela's last summer, worked good for 45 minutes, ice would melt, and that was that. I now have plenty of battery power to experiment. No way I would try and sail with a over-the-hatch unit dangling there so I'm trying to find something that requires neither venting nor drilling additional holes below my waterline, already have 7, that's enough.

 

[Steve Walsh]

I've sailed many times with my CruiserAir hatch a/c unit mounted in the salon hatch and it has never moved, even with rails-down sailing on either tack. I did thread a vinyl covered locking bike cable thru the handle in case it decided to jump ship, but nothing holds it in place except weight and the curve of the outlet. It would be easy to drill holes in the outlet for a dowel rod to be installed under the hatch.I have read that a Honda 2000 has no trouble running this a/c, which does a good job of removing the humidity in my Newport 28. It will hold cabin temp at 80 on a 95 degree day and freeze us after the sun goes down. Biggest gripe is that is is heavy and a PIA to store and move in/out of the cabin.