How to cool off your boat?

[SailorX]

Hi everyone,

I got solar panel and a wind generator so I have quite some power. I also have a cable to get power at the docks.
I am now looking for a device to cool off the inside of my boat where I sit and sleep etc.

A/C is overkill I think and I am afraid of mold and moist maybe with that.

How about an aircooler? Would that also be high risk of mold?
What other methods could be used to keep inside cool?
Power wouldn't be an issue.

I have a defender 27 (Is a bit dirty I know, had been sitting in harbor for 2 years)

[nuku34]

Sailor X:
You'll need to be a lot more specific if you want help on this forum.

The small flexible solar panel and the older style wind generator are not going to give you "quite some power" if you are talking about running a standard A.C. air conditioner unit on battery power. Frankly that's impossible with the setup you have; you could only do it with shore power.
Unless you have a dehumidifier running on A.C. shore power, you are always going to have a mold problem if you are living in a tropical humid climate (by the way, where are you living?)

What is an "aircooler"? is that just a fan?

You don't mention what sort and size of batteries you have; that's critical if you are going to be using d.c. power.

[Pegu Club]

You might consider a boat sun shade to help mitigate the suns direct contact with your boat, when at the dock the smallest window A/C ducted through a overhead hatch would be effective, and done correctly, can be removed relatively easily when one goes out for a sail. We did the sun shade & A/C thing one summer in Cambridge Maryland, it worked well.

Fair winds,

[CaptTom]

^^^ What @nuku34 said.

But you mention shore power. So proper marine air conditioning is an option.

An air conditioner is a great dehumidifier. People in tropical climates (some here in Maine, too) keep them running all the time to prevent mildew and mold growth in boats which are left closed up for long periods.

A marine air conditioner is a water source heat pump. Sort of like the ground-source heat pumps the salesmen (incorrectly) call "geothermal" in dirt-based homes. They're popular because using water (or the ground) as the heat source (and heat sink, when cooling) is more efficient than using air, and they can be tucked in any convenient corner of the boat, without large heat exchangers and associated fans. You buy the complete unit, hook up water hoses and air ducts, and you're in business.

A budget alternative is to hook up an RV-type air-source air conditioner in a hatch. Doesn't look as good, and not quite as efficient, but on those hot, humid days you'll be glad you have it.

Eidt: @Pegu Club beat me too it: A sun shade would make a huge difference on a sunny day.

[valhalla360]

Shade is a good option. Even if running air/con, it helps by reducing the heat that the air/con has to pull out.

A dehumidifier is just an air/con unit that dumps both the cold and the heat back into the interior. If it's hot, an air/con is effectively a dehumidifier.

Your solar/wind array doesn't look like it would be anything close to running an air/con.

Air cooler: Are you thinking of a swamp cooler? These use evaporation to cool the air. Two problems:
- They only really work in a low humidity environment (think desert, not humid coastal area)
- They do add moisture to the air increasing the likelihood of mold.

If you want a cheap option, you could fit a 5000btu window air/con to the hatchway. Looks redneck and is a bit of a pain to mount and remove but cheap as chips compared to a marine unit...still not going to power it off solar.

[Rumrace]

I screwed and glued some 1/4 plywood and made a box which fit in a mid cabin window.
The box had a new Chevy heater core and two 80mm pc fans. A cheap bilge pump sat in the bottom of an ice cooler. I ran it on a separate motorcycle battery well before lithium was a thing. Worked great icy cold in fact. Did not remove humidity but a fan was pushing out a vent to help there. A boom shade will go a long way to reduce heat in the aft. Lots of boats are built without “E” glass. Sometimes a film can calm down windows without darkening them.
I remember an AMC car got laughed off the market cause it was a glass heat dome.
The Tesla X biggest complaint was the front glass extended to far on the roof making the heat unbearable as well as glare.
So canvas sun shades double as ventilation scoops. The Tesla needs a 49 Merc sun visor. Dark canvas holds more heat and shows off bird poop much better.
Sumbrella make a lighter fabric which match most of their heavy canvas. It’s not as waterproof and about 1/3 the weight and half the weisbeck rating but ideal to deflect heat. So match up your canvas but you sun shade not heavy all weather canvas.

[ItDepends]

Originally Posted by SailorX

Hi everyone,

I got solar panel and a wind generator so I have quite some power. I also have a cable to get power at the docks.
I am now looking for a device to cool off the inside of my boat where I sit and sleep etc.

A/C is overkill I think and I am afraid of mold and moist maybe with that.

How about an aircooler? Would that also be high risk of mold?
What other methods could be used to keep inside cool?
Power wouldn't be an issue.

I have a defender 27 (Is a bit dirty I know, had been sitting in harbor for 2 years)

Actually you have it quite backwards. A/C is by far the BEST way to reduce humidity and mold inside of the boat, but would be hard to implement on a boat that small.

When you say an “air cooler” I assume what you are talking about is what is sometimes called a “swamp cooler”. Using evaporating water to cool air. That would be about the best possible way to turn your boat into a lush mold garden.

In the absence of A/C, SHADE, and FANS. It is far more pleasant at anchor where there is more likely to be a breeze. We never run A/C at anchor, even in the tropics. At a slip, where a breeze through the boat can be hard to come by, different story.

[SailorX]

Thank you for the replies.

Air cooler must be the swamp cooler indeed. It´s called an air cooler here.
Something like this: https://media.s-bol.com/3Y29G95k8Vq4.../1200x1200.jpg

I do have a large 12000 btu A/C in my house but I haven't seen any smaller devices than the one I have. This would never fit on my boat.

I assumed I would have enough power for a small swamp cooler.
I do have shore power, but when on shore it's usually at night so there's no heat to take away. I'm mostly needing it for the days out on the water and when I want to cook some food inside for example. Or just hang out a hour while anchored maybe.

I don't have as much power as I think then? But yeah the swamp cooler wouldn't work anyway on the boat. But for a proper small A/C device it's probably not enough power?

I have 3 pretty large batteries. I'm unsure what type exactly and what kind of batteries. I would have to take a look. Oh and If im not mistaken, the batteries also charge when the engine/motor is running. What would be another method of gaining power besides the one's I have?

I have to say that I have quite a bit of equipment.
Stove, oven, tv, fridge and a bunch of raymarine equipment and I haven't managed to drain my power yet haha.

[Rumrace]

I’m sure you could run air on batteries I can’t. The wiring comes no where near the house wiring. The outlet for shore cord is separate and the little Onan fires up before the air will start at anchor.
I have 4 100amp Lithium in house banks and 2 more in the bow no chance they would run the air. It’s a silly option without the generator. And adding after the fact costs way more with the ducts and switches. You can improve some systems with iris controls.

[SailorX]

I actually have two 220volt sockets on my boat for devices used in houses.
Something like this:

Thanks to this I could easily bring my electric water boiler from home for example


Must have been added by previous owner.

I haven't really done much with them yet though.
The fridge is with a compressor, I turn it on with a switch at a panel. So I guess it uses not many power at all.

What about normal fans and keeping the deck window open? Will it work?

[seandepagnier]

You best bet is a wind scoop.

After, an electric fan. Larger slower rotating fans are more efficient. I use a 12v rv fan but run it at 5 volts with a converter and it uses less than 1 amp but keeps me cool

[CaptTom]

I'm afraid you're going to have to do some math (aka, "maths.")

You need to know the Amp-hour rating of your house battery bank.
You need to know how many Amps each appliance or piece of equipment draws.
You need to know how the rated Amperage of your charging systems.
You need to know the charging profile of your batteries.
Assuming you have an inverter to power the 240VAC outlets when not on shore power, you need to know it's rated output.

I think you're getting the picture. You have some homework to do. You can't just flip everything on and hope for the best. You need to manage your batteries and your loads.

I hope we're not discouraging you. Pick where you want to start and ask some specific questions here. It's not difficult once you see how everything is related.

[Idaho]

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[JPA Cate]

We have never had anything but windscoop and lowest possible elec. draw fans. Used to use Hella 2 speed, always on low speed, now use mainly Caframo. I discovered that as long as I can dry my perspiration, I can sleep.

Also, agree that tenting helps reduce the temp of the air that comes in the boat. I made a windscoop that one could reef for the foredeck on our previous boat, and its top shaded the hatch. The air coming down always felt cooler than ambient outside. It was mostly successful, but you had to close the hatch down quite a bit to help keep out the rain.

Anything you can do that does not consume energy and can cool you is the easiest (and lowest footprint) way to go.

If you're sleeping in the V-berth, making a foredeck awning is probably the easiest thing to do to cool the v-berth [it will shade the hatch, too], and adding a fan to blow on you there will make a big difference.

Ann

[meirriba]

Originally Posted by SailorX

Hi everyone,

I got solar panel and a wind generator so I have quite some power. I also have a cable to get power at the docks.
I am now looking for a device to cool off the inside of my boat where I sit and sleep etc.

A/C is overkill I think and I am afraid of mold and moist maybe with that.

How about an aircooler? Would that also be high risk of mold?
What other methods could be used to keep inside cool?
Power wouldn't be an issue.

I have a defender 27 (Is a bit dirty I know, had been sitting in harbor for 2 years)

If you do go the A/C path, there is no reason to worry about moisture. A/C dries the air.
It will help to dehumidify the boat.