Live Aboard In The Tropics, is air-conditioning a must have?

[Moonos]

After sailing in Thailand last April and finding the hot/humid weather just far too strong to sleep in, I thought that air-conditioning would be a must have. Admittedly, there was no wind but i'm not totally convinced a breeze would have fixed things short of a really good cross ventilation.

During the day I love the heat, the hotter the better as long as i'm near the ocean, but when it comes time to sleep I really struggle in the extreme hot weather.

Looking at needs vs want's really got me thinking. The reality is that air-conditioning and the cost of running a generator really puts a damper on my search for a simpler life on the hook in a remote tropical place.

I don't really think fans make much of a difference in a cabin, it simply recirculates hot air.

I am a HVAC tech so I understand the theory quite well.

I'm interested in how people manage live aboard in the tropics?
Is air-conditioning a must have for people in the tropics?
Does anyone sleep in the cockpit in calm conditions to keep cooler? That's what i did one night in thailand. It wasn't really comfortable, but I imagine it could easily be done on a cat with more room and a proper matress.

One concept I have thought about is outside air ducting. At night the cabin will often be quite warm, but the outside air a bit cooler (admittedly still quite humid). What about an inline fan drawing in outside air into the cabin and spilling it out a top hatch combined with a circulating fan? This system works quite well in a large building, however a boat environment is quite different.

[StuM]

It's obviously not a must have. Millions of people live in the tropics without it.
But it sure is nice to have at times, especially if there is no breeze.

I don't know how long you were in Thailand, but you also acclimatize after a while. After a month or two, you don't notice the heat nearly as much as when you first arrive in the tropics.

When parked in the marina with little breeze, we tend to run the aircon in the afternoon at this time of the year- but don't run it at night. It's late evening now and I'm quite comfortable just having hatches open and fans running.

And we don't have a generator - we only use aircon when on shorepower. Anchored out or sailing there is no real need for it around here. But of course, we also have a large comfortable cockpit

It also depends on where in the tropics. It was hardly used at all here between May and the beginning of this month but will get a lot more use between now and next May.

[model 10]

Some boats just don't have enough windows for the tropics. Those that do usually can get by with fans.

[Triumphant]

Originally Posted by Guy

Some boats just don't have enough windows for the tropics. Those that do usually can get by with fans.

11 years in the Tropics with just fans.

You can buy a lot of fans before you get anywhere near the price of an on board A/C unit and you also do not have to have shore power or a genny

[2Hulls]

We don't have a genset nor air conditioning and have been quite comfy in the tropics. But we haven't spent much time in the tropics in the summer months. Until recently we didn't even have any fans, but we installed some in our current refit.

Of importance is having good natural ventilation and being on the hook vs in a marina. On the hook the boat will lay to the wind and the passive ventilation designed in will work as it's supposed to - if it's there to begin with.....

A downside is needing to jump up and close the windows/hatches/ports when the almost nightly brief rain comes through.

That said, we have enjoyed it when invited aboard a boat with their ac running.

Dave

[Reefmagnet]

Boat design for natural ventilation and fans. However, acclimatisation is the key factor. In my experience it takes around three years to fully acclimatise to tropical summers which are more about humidity than outright heat.

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[Muckle Flugga]

Originally Posted by Moonos

After sailing in Thailand last April and finding the hot/humid weather just far too strong to sleep in, I thought that air-conditioning would be a must have. Admittedly, there was no wind but i'm not totally convinced a breeze would have fixed things short of a really good cross ventilation.

During the day I love the heat, the hotter the better as long as i'm near the ocean, but when it comes time to sleep I really struggle in the extreme hot weather.

Looking at needs vs want's really got me thinking. The reality is that air-conditioning and the cost of running a generator really puts a damper on my search for a simpler life on the hook in a remote tropical place.

I don't really think fans make much of a difference in a cabin, it simply recirculates hot air.

I am a HVAC tech so I understand the theory quite well.

I'm interested in how people manage live aboard in the tropics?
Is air-conditioning a must have for people in the tropics?
Does anyone sleep in the cockpit in calm conditions to keep cooler? That's what i did one night in thailand. It wasn't really comfortable, but I imagine it could easily be done on a cat with more room and a proper matress.

One concept I have thought about is outside air ducting. At night the cabin will often be quite warm, but the outside air a bit cooler (admittedly still quite humid). What about an inline fan drawing in outside air into the cabin and spilling it out a top hatch combined with a circulating fan? This system works quite well in a large building, however a boat environment is quite different.

1. Aircon is a waste of fuel by and large, and often barely cools the boat as running the generator is a pretty big heat source… when you shut it off… the heat returns with a vengeance, plus the additional heat from the genny block, now starved of an external heat sink, and convecting into the boat. That is, unless you have a very big boat and a very big budget, with a remote and heat sealed engine room. Aircon on smaller vessels is really only useful on shore power in a marina, where it is in fact a godsend.

2. Fans do work. It is not the temperature of the air but the rapidity of evaporation of the sweat which makes the difference.

3. Eat less. Drink more (but not alcohol if possible). Eating a "normal" amount of food is wasted in the tropics, and the carbs just cause constant overheat. Slim your diet and change it. It helps.

4. SHADE: The best solution is a full boat canopy. Makes an ENORMOUS difference.

5. Ventilation: windscoops and the like definitely assist.

6. "Sweat the boat": use saltwater or preferably (if you have a big watermaker) freshwater to soak the decks a few times a day in the worst of it if in equatorial waters. It takes less than you might think, and makes a significant difference overall.

7. Suck it up: acclimatisation and tolerance are the other necessary tools in the tropics. Stick it out until you get used to it. In Indonesia I frequently record temperatures in the high 40s celsius on deck, and belowdecks usually not lower than 30C until after midnight. It's just the way it works.

Aye,

S

[zboss]

I second the canopy. If you are planning on spending any time in the tropics they are a must have.

When we are at a dock, we will run a portable A/C unit... we don't have A/C built into the boat.

[sailnow2011]

I know its not the tropics, but after two years in FL I feel cold in 67 degree weather, and not too bad in 85 degree weather. Anything over 90 kills me dead still. Lets see what next year brings.

[wrwakefield]

Originally Posted by Moonos

After sailing in Thailand last April and finding the hot/humid weather just far too strong to sleep in, I thought that air-conditioning would be a must have. Admittedly, there was no wind but i'm not totally convinced a breeze would have fixed things short of a really good cross ventilation.

During the day I love the heat, the hotter the better as long as i'm near the ocean, but when it comes time to sleep I really struggle in the extreme hot weather.

Looking at needs vs want's really got me thinking. The reality is that air-conditioning and the cost of running a generator really puts a damper on my search for a simpler life on the hook in a remote tropical place.

I don't really think fans make much of a difference in a cabin, it simply recirculates hot air.

I am a HVAC tech so I understand the theory quite well.

I'm interested in how people manage live aboard in the tropics?
Is air-conditioning a must have for people in the tropics?
Does anyone sleep in the cockpit in calm conditions to keep cooler? That's what i did one night in thailand. It wasn't really comfortable, but I imagine it could easily be done on a cat with more room and a proper matress.

One concept I have thought about is outside air ducting. At night the cabin will often be quite warm, but the outside air a bit cooler (admittedly still quite humid). What about an inline fan drawing in outside air into the cabin and spilling it out a top hatch combined with a circulating fan? This system works quite well in a large building, however a boat environment is quite different.

Moonos,

I sailed in the tropics in the past on a previous boat without air conditioning. I got by, but now I guess I've been living in higher latitudes for too long. When I join friends in tropical locations, I'm a safety hazard since there is always a pool of water around me and I never stop sweating. So to answer your question for myself, yes, I will benefit from air conditioning when I return to that kind of heat and humidity.

With that said, it just so happens our current vessel came from the tropics and the previous owner installed 3 separately controlled air conditioning units. [2- 18k BTU; 1- 9k zoned on separate thermostats in the forward cabin; amidships; and aft cabin.] They share common plumbing and a single pump for the raw water cooling circuit. The 10kw generator in an insulated, isolated engine room powers them well [I've tested them on 90°F days...]

the idea is you only need to run the unit(s) needed for the desired results. For sleeping, that would be the aft cabin in our case.

Currently we are at latitude 56°N, so we are only using the [resistance] heating side of the air conditioners to keep the boat comfortable- when at the dock with shore power. [We have other heating systems we use when not on shore power...]

I mention all this in case it gives you ideas for your installation should you decide to splurge. Ours seems to be well thought-out and has been well tested in the tropics.

Cheers!

Bill

[Moonos]

All good advice, thanks everyone.

A Bimini shade over much of the boat, good opening hatches to catch the natural breeze and wetting down the deck all seem like excellent ideas. It is best to prevent the heat entering, rather than trying to cool.

Maybe a compromise might be a single air con in the main cabin for when in a marina. This could be run off a decent sized alternator when motoring, and a 2kw Honda generator as a emergency/backup. I understand the Honda would not be a long term solution for the air con.

[Reefmagnet]

Not sure I'd be wetting stuff down in high humidity. Evaporative cooling isn't that great in this circumstance and all that extra moisture can just add to the already heavy air.

[model 10]

Originally Posted by Reefmagnet

Not sure I'd be wetting stuff down in high humidity. Evaporative cooling isn't that great in this circumstance and all that extra moisture can just add to the already heavy air.

How about a salt water mister in the cockpit? That would be cool.

[KStepman]

That depends on where you are and when. In the East Caribbean island chains, especially in the Winter of that hemisphere, it is very comfortable at anchor with the hatches open into the trade winds, perhaps with a 12V fan in each cabin. If it is Summer, and Trinidad, with the heat and humidity coming off the South American continent, and no trade winds. Yes. A/C is helpful. Everywhere between and it's a personal opinion.


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[Tientos]

In Thailand and other tropical areas, we just have our specially made 4 sided wind scoops foe and aft and a fan for each side of the double bunk. Always cool...


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