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Must respectfully disagree with Cat about NY not needing AC. It was sweltering hot on the Erie Canal this summer. Unusually hot acording to the locals. Wished we had AC the whole time. Smile

I stand admonished....you must have picked that one bad week Greg - sorry.

If it does get nasty hot mid state, you can take the Cayuga Seneca branch down the the big Finger Lakes, then sail and drink the wine country until you dont care about the heat anymore.

(on the off topic of BWI, I was at the Albany Fireworks one July 4th, and the Sheriff was hassling the guys next to us - no PFDs, overloaded with both people and beer, loud - I overheard the guy on the boat asking why they werent hassling us drinking wine? I also heard the reply - People wearing PFDS and drinking wine never give us a problem.....heh heh......

Ive always dreamed of a simple A/C mod where a small motor picks up fresh/sea water at 50-60F, pushes it through a car type heater core, and a fan blows cool air into the boat. I think you could put this together for <$100 and run it on either DC or shore power. It would not dehumidify, but would take the swelters off. Im even wondering if I could modify my Zodi dog shower to do double duty in this regard. Hmmmmmm.

[quote="Catigale"]- People wearing PFDS and drinking wine never give us a problem.....heh heh......[quote]

Too true....two different type of boater and almost mutually exclusive between the two groups.....I would fall under the PFD and Wine group...but only if it is good wine!

Yea, that "swamp cooler" concept isn't going to do much good around here. We don't get that hot (never gets much above low 90's here), we just get really high humidity. I think A/C which lowers humidity is the only reasonable answer.

I was at home depot yesterday and looked at a couple A/C's. They had a 5000 and a 6500 which both weighed the same (48.5 lbs). The 6500 had remote control and didn't cost much more. I wonder if that is the lightest window unit you can get. My dinghy motor is only 12.5 lbs...

I have a 5000 btu unit that i have on a mount that goes in the companionway. Works nicely after these florida hurricanes too...It works well and can store easily. I do think that in an emergency i might have to jump over it or at least lift it a bit and shove it out. I have a honda 2000 generator that runs it nicely with an eco switch that slows the rps of the motor down when not needed. I have tried larger a/c unit but find the 2000 can tend to trip by a larger unit. The honda sits nicely in the back under the helm seat on a rubber mat and I have a system so I can connect it to the boats gas tank to run it all night and not just for 3-4 hrs. I contemplated installing a marine a/c under the dinette but it would take more power to turn it than a 2000 gen. So, I am glad I did not..as I had another kid and neglected the boat for over a year and am just getting back into it again.. Only bad thing is mother florida has eaten the trailer up and a new galvie is in the near future as I dont trust this trailer to go down the street more than once..

Hello GBroga, Im in daytona and I have a M at the halifax harbor marina, It sounds like you have the same a/c system Im thinking about getting. Does the 5000 btu keep the cabin cool.
Bob

Catigale wrote:Ive always dreamed of a simple A/C mod where a small motor picks up fresh/sea water at 50-60F, pushes it through a car type heater core, and a fan blows cool air into the boat. I think you could put this together for <$100 and run it on either DC or shore power.

This has been proposed several times before. I don't believe it will work. Small, single pass car type heater or A/C cores are designed to run at temperature differentials of 100 degrees or more. The temperature difference between the 50-60 degree water and 90 degree air may seem like a lot, but in terms of heat transfer, it isn't. In terms of cooling, you're unlikely to get out of it anything more than fan forced hot air, you'd be surprised at how much power it takes to force air through a heater core, and the pumping power to circulate the water will be totally wasted. In order to provide any kind of cooling from a temperature differential this small, you'll need a super efficient multiple pass water to air heat exchanger. These things don't come cheap and the power required to run the fan will be significantly higher than that to run a standard A/C fan; these typically run around 10A @12VDC on high. That's a battery killer.

If you search in the archives you'll find several such previous discussions, wherein those who didn't like my answer stated they were going to try it anyway. To my knowledge we've yet to hear back from any of them.

If you have shore power or already have a generator, buy a small A/C for <$100 and be done with it, just as these guys are proposing.

If you're limited to 12V only, I believe any kind of heat exchanger is out of the question, power wise. The key is to just keep the air moving. We've had good pretty good success with a combination of a windscoop in the forward hatch and a small 12V propeller type fan blowing air only. We sleep in the V-berth for exactly this reason; if you have to relegate folks to the aft, under cockpit berth, probably the windscoop won't help much unless you add auxiliary vents.

The fan I picked up for <$15 at WalMart and it draws less than 1A.


The windscoop worked fine in June in Bimini, at anchor when the boat was always bow to wind and there was always wind. It would not work so well at a dock when the wind comes from a random direction. With some attention to attachment options you can swivel it to face nearly any direction, but that can become a PITA if the wind is constantly shifting direction.

Thanks Chip - it turns out I have a collection of air to water XGRs from work, otherwise agree that the cost for this runs through the roof.

Since I have two 8 years olds, one will pedal the stationary bike linked to the fan blowing the air into the AC, in shifts throughout the night.

The power consumption for the fan is a problem indeed.

Still 6 hours at 10 amps is 1/2 capacity of a third "AC battery", which isnt ridiculous if you have it already and arent using it every night.

Sorry for the rehash - I think you are right, no one has worked this successfully yet.

The DC Breeze

http://www.dcbreeze.com/

Has one tried one of these? Any thoughts on how well they work? Is loading ice in a cooler easier than loading an AC unit in the companion way?

At $2500, thats several window units...



I was one of those that was going to try the water cooling system. I have not yet tried it. I don't expect AC unit type results. I don't know what I expect, I guess I'm just hoping for measurable results...

48 amps DC input? The concept is truly ridiculous for a boat the size of the Mac. Even if you only ran it a fraction of the time, it would require a monster battery bank to support it.

Recharging the battery bank at 15-20 amps typical max would take three-four hours of outbopard operation for each hour of cooling. Running the outboard for extended periods to make up for power squandered for air conditioning makes no sense. If you really can't do without A/C, for less than half the price you could get a nice, quiet, high efficiency generator like the Honda EU2000, and a window air conditioner.

Even a generator and one of those very expensive marine A/C units would cost less than this thing.

If you really wanted to live well you could even do the generator, a window A/C, and throw in one of those expensive marine rerfrigerators, and still have a couple hundred change on your original $2500.

In truth, I believe a 5,000BTU unit run continuously would flat freeze you out on the Mac. Even so if you had to run it (say) 25%, that's two size 24 (standard Mac size) batteries for the A/C alone, no other overnight loads, and probably no starting the motor the next day unless you had a third size 24. Regardless of the battery bank, three to four hours running the outboard to recharge the batteries, for eight hours of cooling. There is a better way.

What about those drop in tray's
I saw them somewhere on the net a tray you set on top of a "couple select Igloo /Coleman" coolers that you fill with ice and a small 12v. fan does the rest. No doubt not for weeks but might well work for a night or two .

What about those drop in tray's
I saw them somewhere on the net a tray you set on top of a "couple select Igloo /Coleman" coolers that you fill with ice and a small 12v. fan does the rest. No doubt not for weeks but might well work for a night or two .

I wonder how humid that would be? And if you're out for the weekend, what about the next night?

Chip H. - I think it was a $15.00 Walmart fan you mentioned above.
How loud is it? Recall the brand name or model name?
Several years ago I bought a cheap 12 v fan at Kmart, but it sounded like a cement mixer, so I took it back..

Well they claimed and I could see/imagine where 20 lbs of ice might well last for two nights?? Humidity?? Dont know about that one but you can only saturate the air so much then . . .they call it rain