holy grail solar air conditioning unit that isnt powered by honda generators and is

not actually a solar air conditioning unit, or, for lack of a better term, The Sandbox.

This is a place for alternative cooling systems for boats that have limited space/weight considerations to take into account.

If conventional a/c won't work on your boat and you have an idea for an alternate system, post it here.

I'll start.
For a boat at anchor would it be feasible to drop a deep weighted hose and pull cold water from depth to run through cooling coils in passenger compartment with a small pump?
This is assuming that when a boat is underway, the breeze alone would be sufficient to make living conditions tolerable on-board with credits going to eightyape.

 

If its a single handed sailor then noones going to be in the cabin whilst your underway are they?
perfectly viable idea especially if supplemented with scoops to pull surface water to circulate through the same system when underway if you can put up with a little extra drag- under power you could just add a take off to the engine cooling circuit pre engine to maintain the temp under power-or just leave it hanging out there!
I think those guys who sell the drag behind generators do ok even though you get the drag issue.

 

It wouldn't take much power to use sea water for comfort cooling, I'd have thought. An array of small bore pipes fitted to the inner cabin roof and fed with sea water should do a pretty good job of cooling the boat. Solar thermal hot water systems use low power circulating pumps, often powered by a small solar panel so they may be worth looking at for such a system. An intake down in the keel, with the pump well above the water line (I think they self-prime OK) would be safe and probably pretty effective.

If the cabin roof is kept close to sea temperature I reckon the cabin itself would stay pretty tolerable, even in the tropics. Add in a tarp rigged as a sun screen to shade the cabin when at anchor might improve performance even more.

 

Jeremy,
but the summer water temperature in the Med as high as 30 °C (and seldom below 28 °C), and I suspect it is not very different in other places around the globe at similar latitudes.
It means that the cabin temperature would be (at least) around 33-34 °C, which is not comfortable at all...

 

The pipe would have to go down to -150 meters to suck sufficiently cold water to correctly dehumidify and cool down the cabin space: http://en.wikipedia.org/wiki/Thermocline .
The hose would be 3/4" for the necessary 600 liters/h (160 gal/h), would weigh around 0.63 kg/m (0.42 lb/ft - http://www.hosecraftusa.com/model/RW1_Rubber_Water_Hose) and would require a pump which absorbs around 100 W.
So, the total weight of the hose would be 0.63*150 = 95 kg, which means it would be impossible to pull it up from the water - even considering the reduced weight in the water (due to buoyancy). So a deploying mechanical system is necessary, either manual or electric, which will add another 15-20 kg and 0.5 kW of necessary power. It means a battery is needed with relative electronics.
If you want to power it with solar, at least one panel will be necessary, or 3 panels without battery.

At the end, we end up with some 180 kg for the pumping system, in addition to the standard heating system which will be necessary for nights or winter season.
The question now is: is it really worth it? I don't know. I wouldn't put it on my boat, but someone else perhaps would. So my analysis stops right here, at the technical side - also because people might start calling me a naysayer.

Cheers.

 

http://www.ioes.saga-u.ac.jp/en/about_oetc.html

I think your right daiquiri the hull intake cooling is not too viable anywhere near the equator where the aircon would be most needed so you would have to run a pipe to around 10m or so-
but the temp dropoff gradient is most severe in the first 10m of seawater - understanding the hyrdodynamics of a given hull and where there is a "rollback" in the turbulence that effectively pulls up deep water to a point where it can be pulled in might be viable place to put the "scoops". or on keeled boats just stick it right down the bottomof the keel and if you can get aircon for the price of a few hose pipes then it might just fly/float.
If you consider powered craft running engines with load on the alternator to run conventional A/C then the extra drag of a submerged hose would probably prove more efficient, make sure its smooth enough not to snag - or sod the snagging and put hyrofoils on it to keep it deep....

 

<removed>
get some ******* manners.

 

What's wrong with my manners??
Analyzing your idea has taken a lots of time from my other duties, yet I have done it because it I was curious to discover the results. But I really can't spend too much time into wrapping words in a candy paper, I'm sorry for that.

 

The idea was to attach it to anchor for cooling for static vessels -for those of us who maybe cant afford or dont want dirty great polluting aircon units that suck power.
so the mechanics argument is solved by integrating with the anchor chain, youwouldnt need anything like 150m in certain parts of the world - incidentally the thermocline varies massively globally too - and river water/ estuary water varies even more- on a river the pump could be supplemented by river flow, or on sea it could be assisted with wave power. the flow rates you have described -not sure where yougot your figures from either.- they would vary very much depending on the size of the boat- quality of insulation.
Its fine being a naysayer being a smug <removed>

 

well dont bother then if you got better things to do? but there is an air to the way you and your little bully buddy have commented on this thrrad and the other I posted on.
I dont need to even look through the forums to find this patronising manner is in a lot of your posts when you are being a clever <removed>
No need to candy coat nothing a bad idea is a bad idea and its appreciated input ut its the snides that piss me and others off and I know im not the first to bite because that is what you are after.
I always go for straight punch in the jaw though not a snigger behind my hand...
<removed>
you just call it like you think and say its a stupid idea instead of trying to get a bite and then acting all superior when i take the bait.
which is what the next post from you will be no doubt- the internet is full of superior ,smug self proclaimed experts who behave like bullies just like you.

 

Well, this is the third in a row, which means my personal red card for you. Au revoir from me, eightyape. You can play your childish games of insulting people with those who have time for that sort of things.

 

yep you got the bite, get a lot o folks banned do you?
is it your favourite game - grow up.

 

An alternative idea is not to pump up cold water, but to send down something that hot that is cooled and then brought back up.
water is good, but maybe something else might work better,
like say phase change materials. I dunno, but there is a vast resource of the sea that is there to take advantage of compared to a land-based solution.

In the electric car world, A/C is a huge expensive, and there is lots of discussion on how to avoid or reduce it. Mostly the idea is to cool people and not the car. Cars are about the worst insulated things around, and I think boats might be second on the list, but someone please enlighten me on that. Preventing the sun from heating the cabin in the first place would be priority one and the most effective cooling method.

 

well, this thread went south in a handbasket. I really fail to see how daiquiri is missing any manners. He is not the one who has to use *** instead of actual letters to avoid beeing flagged.

Padilac

 

I'm wondering if that's called going up in flames or going down in flames.