Cooling the Cabin of a Sailboat

[hellosailor]

Sara, I'd suggest you rent or acquire a cargo cube (20' or 40' size) and put it in a nice sunny spot. Now, record the daytime temperatures inside. Then try to use a single deep-cell battery to cool it down to 75F all day without a recharge.

That'll give you a ballpark place to start from. Boats have limited power supplies, usually zero insulation, and limited resources of all kinds. Wind is nice when you've got it. Cooler water from under the thermocline is nice, if you can reach it and deal with the salt corrosion problems.

But that cargo cube will give you a much cheaper "boat" to actually start working with.

[Tampabayfireman]

Sara,
Look beyond the aspect of marketing it to just boaters... in todays climate, rising energy costs and third world turmoil, if you built it and it works, those will be the areas that will be willing to pay for it... boaters second... design it around solar and passive demand, you will write your own paycheck...

[imagine2frolic]

It depends on what you mean by cooling? Do you mean to chill the air where you might need a cover? Do you mean to lower the tempature, so life is comfortable?.......i2f

[bloodhunter]

Sara,
I can tell you that in places we've cruised humidity is as much a problem as temperature. We have a lightweight white awning we put up over the cabin and cockpit when we're at anchor and that can lower the temp inside the boat to liveable levels but the humidity can still make things very uncomfortable..
In any case our boat has a 600 AH house battery bank and we generally try not to draw it down more that 30-40 pct. Going above 50 pct drawdown can damage the batteries. The house bank is charged by two big solar panels and by the engine alternator when it's running. Our one major draw is our refrigerator which draws 40-50 amps /day. We have LED lighting and efficient fans so add another 10-20 amps, add in other draws such as stereo, ssb radio. That leave 100 amps or so -- figure 10-12 amps/hour for AC (thats 12-volt amps).
While it would be nice to cool our entire boat, we'd settle for cooling the sleeping cabin(s). We have two but we'd only cool one unless we had guests staying with us. That would cut the volume needed to be cooled by over half.
I don't think we're untypical as cruisers go, so that's what you'd have to work with.
Good luck and thanks for thinking of us.

[s/v Jedi]

I think the single most important thing is to design a decent fan (there's none on the market that I am aware of) using these guidelines:

- powered by 12V DC (and a 24V version later)
- completely balanced... no vibration whatsoever
- corrosion proof (no metal where plastic works)
- a decent air displacement with multiple settings
- high efficiency ratio "air displacement" : "watts consumed"
- mounting system that allows any orientation while maintaining stability and keeping it vibration free (this is where many fail)
- durability: it must last at least 5 years of continuous operation

For A/C systems: we just installed a new "high efficiency" CruisAir Stowaway unit, replacing an older one of the same brand. The new one is 18kBTU while the old one was 16kBTU. Despite the bigger capacity, it only uses 75-80% of the power of the old unit. I don't think there is much to gain on that field.

cheers,
Nick.

[Bash]

I agree with post #19. If you can chill my sleeping cabin without requiring me to burn fossil fuels to run the system, I'll buy it.

[Bash]

Nick, have you looked at the Sirocco Cabin Fan by Caframo? I've been changing all my cabin fans over to this, despite the expense. It seems to meet your design parameters.

Caframo- Innovation and Excellence

[bloodhunter]

Jedi,
Replaced my old cabin fans with Caframo Sirocco fans a couple of years ago and have nothing but praise for them. They are quiet (our main objection to our old fans), since they have three speeds they can be set for minimal power consumption and they still move enough air to keep us comfotable. We have five of them, one in each of the sleeping cabins, two in the main salon and one in the galley.
I have no connection to Caframo or anyone who sells them.

[DallasAB]

Instead of cooling the entire cabin how about some sort of "comfort blanket" for sleeping. Sorta like a heating pad, only in reverse. Circulate some cold water through tubes or something much more brilliant than that.

[srdrzdwsk]

Hi everyone,

I have a question about the mast of a typical sailboat. Are they most commonly made out of aluminum? Do they disassemble into smaller pieces for easier transportation, if so, how big are the individual pieces? And, is the mast typically hollow?

Thanks,
Sara

[James S]

They are typically hollow aluminum extrusion and are one piece....we are starting to see more made from carbon fiber, also hollow...but I'll be a while before their numbers over take aluminum.
Some masts are "stepped" (standing) on the deck....some pass through the deck and are stepped in the bilge (under the "sole" or floor)
They generally have electrical wires or wires in conduit running their length…also most have lines or cables (halyards) inside them that raise and lower various sails.

[boatman61]

As a Long Term live aboard on a limited budget I find anchorage spots where there's a breeze, open all hatches and port lights and deploy my wind scoops.. this provides a cooling through flow of air in the cabins... no noisy fans/generators etc; also as stated by others, strategically positioned awnings can be a great help....
I'm against to many electrical gee-gaws on my boats as it goes against the KISS PRINCIPLE...... more expensive stuff to maintain...
Keep It Simple Stupid.....
In a Marina try using a mister spray of cold water on your base sheet ... works a treat...
just don't over do it...

Nothing more annoying than someone anchoring near you who bangs on a generator and leaves it running 24/7 for their air conditioning....

[Strygaldwir]

We have 12 volt D.C fans aboard our boat (Calframo) They are noisey and are better than nothing, but are not the best solution in my mind. While tied to the doc. we have a couple of portable air conditioning units that we use. When it is REALLY hot we will augment these by putting up a tarp over the boat. Again, not the best solution for us. .

[s/v Jedi]

I have Caframo Bora & Kona fans which go for $100 each at the WM. Actually, I just installed that Bora because of this thread and it is much better than the Hella fan with about the same air displacement.

But that is the trouble. To have any use of these fans, they need to go to the highest setting and even then it is mostly a joke. My $25 miniature tower fans (120V AC) stand far above these expensive toys but yes it is AC powered.

ciao!
Nick.

[zeehag]

ok
here goes. i donot have windscoops. i will not have a/c. i sail ...i runaway from home to cruise..LOL--sailed gulf of mexico in summer last yr---was warm, yes-only was one day not truly tolerable--wind flows thru an anchored boat. not thru a marina boat--lol big difference----i have fan--bought 12 v fan at wally world for 10 dollars--it lasted a month--lol...as long as it was really needed---go figger--lol. but even the humidity and heat were nothing after the canvas tarps were placed over the cpoach house roof to keep the sun off--makes a huge difference--and if done correctly the storm winds wont kill it by tugging it off the boat.....canvas does miraculous things in cooling boats--why get something to drain the batts or cooking fuel when ye can have a canvas cover to keep things under control>>>> is an insulator--keeps sun from directly shining on your boat and heating it up soooom uch ye cant tolerate sleeping...LOL...what do they say---KEEP IT SIMPLE!!!!!!!!!.. the breakage factor is unlimited on boats--canvas may rip--but itisnt as spensive to repair as a/c and other fancy dancy things that arent as easy to use....btw---canvas keeps rain out of boats and ye can keep ports open in storms-for ventilation-wow---new idea..LOL......

there has been an apparent break from the old tradition of using canvas as a tool---i wonder why--is most effective and reliable....is it because the marina residents donot like the appearance of cruising boats?? or what isit--isnt simple to make a/c for boats nor is it reliable--keeping simple keeps ye on th ewater ...lol sailing instead of repairing...