swamp coolers and boats

[tsmwebb]

This summer I've decided to cruise in the desert... Not my first choice to be sure, but family matters are keeping us close to the USA. So, we're in the Northern Sea of Cortez where we expect temps to hit 100F regularly and humidity to be around 30-60%... I have a tiny in-window home AC unit that I can run on the inverter when on shore power or with the engine running. But, it draws too much to run on solar power alone. So, I'm considering building a "swamp" cooler to fit in the same hatch box. Has anyone done anything like this on a boat? Did it work? Of course, it would be really wonderful if I could run the thing on sea water... But, I fear that might be horrid in lots of ways.

My current thinking is that I could make a mister using standard dollar store spray bottle misters linked to a supply hose and pump. They would shoot up at the outside end of the box then there would be one or two squares of nylon screen to catch any large particles and bugs and then a number (2?, 4?) of PC fans... Hmmm... Any feedback?

--Tom.

 

[rpwillia]

I like the idea, would like to hear how this develops

One idea may be a small aquarium type pump that runs off of 12vdc to suck up sea water. Plastic would probably be best to avoid corrosion. Perhaps you could find a small heat exchanger or just a set of 1/2 pvc pipes and have a fan blow air over them.

 

[tsmwebb]

One idea may be a small aquarium type pump that runs off of 12vdc to suck up sea water. Plastic would probably be best to avoid corrosion. Perhaps you could find a small heat exchanger or just a set of 1/2 pvc pipes and have a fan blow air over them.

Good thoughts. Thanks! I'm worried, though, that evaporating sea water will result in salt and dried sea critters everywhere. A smelly and corrosive combo. But maybe not so much if I am constantly drawing new water up and flushing the old over the side... It certainly would be easier on our water budget to use the "water, water all around..." Also, I'm not totally convinced the humidity will be low enough to make it work well... I'm looking at numbers from last year at Guaymas airport and they look very workable, but at anchor maybe not so much... :neutral:

Cheers,

--Tom.

 

[sailingdog]

A better idea might be to have a good awning to shade the boat... Shade alone will drop the temperature significantly... and requires NO POWER...

 

[Capn Ellis]

I second the awning. I made my "redneck bimini" by putting grommets in a $20 cotton painter's dropcloth.

 

[tsmwebb]

Oh yes, I'm a big fan of awnings and hatch covers and port covers. We've go all of those and they've served us well in the tropics. But, we're in a place now where it is expected to reach >100F degrees in the shade and >120F in the sun most days for several months... With water temps around 90F. Even under an awning that sounds hot to me. I'm also told that we will be visited by frequent and sometimes quite violent afternoon and evening thunder-storms. So, awnings need to be kept strong and strikable. Tarps and drop cloths with press in grommets probably aren't up to the job here.

--Tom.

 

[Peggie Hall HeadMistress]

I gotta ask...

With the entire west coast from San Diego to Alaska to choose from, why did you decide to swelter in Baja all summer?

 

[tsmwebb]

With the entire west coast from San Diego to Alaska to choose from, why did you decide to swelter in Baja all summer?

Trust me, it wasn't the plan. We were here when the 'phone rang and we've got to stick close for a bit. Meanwhile the storm season is upon us and we have to deal with that...

--Tom.

 

[Bob McL]

Here in Arizona, we can use swamp coolers (at least some of the time). But when the thunder storms roll in, and the humidity goes up - forget them - and go to the thread on air conditioners. You'll be much happier with an air conditioner and a Honda E2000 generator and not be sticky, drippy wet.

 

[David Sebastian]

I like Capn Ellis post and his "redneck bimini", I hope ya'll don't mind a North Carolina "redneck" with a oday 22 on your hunter post. I have just purchased a cotton painters drop cloth at Home Depot, ( looks better than Lowe's ) a while back to make various items for my boat. I don't suppose it will run off rain very well or does it Capn Ellis?
I made a sun shade from poly tarp, works good, I"m pumped up now to try my hand with cotton. Do you think this cotton would be good for a main sail cover?
Oh yea, good luck Tom
David Sebastian

 

[Bob McL]

BTW - Wallmart has some outdoor fabric at $3.95/yd. Poly one side pvc the other. Not the greatest color selection. . . but for shade and rain it should work better than cotton which weakens quickly due to UV exposure.

 

[Benny]

At 60% humidity and 100 degrees ambient temperature an adequately sized evaporative cooler will only drop the temperature by barely 10 degrees. It is not until the humidity drops to the low 20s that you may be able to get to to a more comfortable 78-80 degrees. The size of the body of water and your proximity to it will preclude low humidities. I would start looking for a portable generator to run that small A/C unit you have. The city of Phoenix used to enjoy single digit humidity back in the 1950s; with the increase in the construction of swimming pools they best they can hope for now is days in the mid teens.

 

[Rick Webb]

I Remember Edwards AFB before Air Conditioning

We hung up wet sheets inside helped out alot

 

[tsmwebb]

Thanks everyone! Many good ideas, much appreciated!

--Tom.

 

[druid]

One thing I looked at (although we don't need A/C up here!), is to use one of the ultra-high-efficiency compressors they're using in DC fridges these days, based on the Danfoss (BT-201?) compressor. They do a decent job of making a freezer drawing only around 4 amps at 12VDC. Could one of these not be converted to an A/C? (I visualize air being blown through a square "tunnel" evap...)

Not cheap but WAY more efficient than a "home" A/C.

druid

 

[bart5008]

I wish you luck in finding a quiet 12volt pump that doesn' draw a lot of power. I have looked high and low without much success. If you do find one, please let me know where.
I have entertained the same idea for a long time. My plans were to use computer cooling fans, a heater core out of a car, and an ice chest. But the bottom cooler water of a lake or ocean will work just as well. There is a company that sells a complete unit for about $2000. Little pricey.

 

[RAD]

Some more ideas from the archives, I remember this dicussion B-4 so type in swamp coolers in the search window
http://oday.sailboatowners.com/index.php?option=com_vbsearch&task=1&Itemid=245