Anyone used an Evaporative Cooler (Swamp Cooler) to cool their Cabin ?? - The Hull Truth

viogator · 09-30-2007, 07:16 PM

A simple design that has been around for a long time, but heard they do not work well in humid climates!? (such as coastal areas). Here in Orlando several people have used ice water in these things to cool an indoor room and it seems to work well.

Anyone tried this to cool a cabin on a small express or WAC ??

billinstuart · 09-30-2007, 07:53 PM

I don't see how they dehumidify very well. They work better in low humidity where evaporation takes place rapidly.

viogator · 09-30-2007, 09:50 PM

They most certainly do not de-humidify, I know that, but thought it could cool things down 10-15 degress by using ice or ice water. Has anyone tried this or something like it?

welder · 09-30-2007, 10:05 PM

You will be fighting black mold in a day or two. Now if you lived in Arizona , go for it.

rubinjames · 10-01-2007, 05:00 PM

Not to cool a room, the driving force (evaporation rate) would be low here
in Florida varing with the relative humidity. However, you would get some
cooling. Look at the TV football games, the big fans you see on the side
lines are spraying a fine mist of water that evaporates and gives some cooling.
In that situation some is better than nothing.

billinstuart · 10-01-2007, 05:11 PM

Dehumidification is an integral part of "air conditioning". Just cool air may feel a little better, but mold does love cool moist environments. Don't do it.

ScarabChris · 10-01-2007, 05:19 PM

Not good if used long term but if you are just using it for a night or two once in a while I don't see an issue.

You can build a closed loop system for better results too.

catfoiler · 10-01-2007, 06:14 PM

If you only need occasionally then I would consider an ice based cooler but evaporative style won't be good at all.

solarfry · 10-01-2007, 08:34 PM

Boater's World has a Couple of 12 Volt fans you place on top of a cooler full of ice to cool down a cabin for about and hour or two.

You can probably make one with a pair of large computer fans and a piece of plywood.

A swamp cooler will not cool at all in Florida. Humidity is too high. They work well in CA, AZ, NM, etc.

20chap04 · 10-01-2007, 08:46 PM

Evaporative cooling units are designed for open areas where additional humidity isn't a concern. I wouldn't think they'd do well in an enclosed area. You'd have major condensation issues along with the associated mold/mildew concerns.

Schmaltz~Herring · 10-01-2007, 09:21 PM

$100.00 5200btus cools great. small size, stows easily, lightweight about 32lbs.
when it craps out throw away. You can find GE's for $70.00. condensate just drains on deck out scupper.

viogator · 10-02-2007, 11:21 PM

Thanks for the info guys.... all good stuff. To answer a few questions, I was just talking about a night or two... not constantly. I would like it would take a couple of days for black mold to start growing, especially if we are venting & running during the day.

I must say that I do like the idea of a cheap window AC unit as the picture shows. Any special considerations using this method?

ggibby · 10-03-2007, 12:31 AM

I keep a couple of those window units for when the hurricanes wipe out the power here in Florida. They generally require about 500 watts of electricity to run, and the starting current is higher, but I was able to get them going with a 900 watt generator -- the regular old style kind, not the inverter type. I have no experience with the inverter type. My generator weighs 58 lbs.

This means you have 115VAC aboard a ship in the water: I would keep my hands WELL AWAY from the plugs once the generator is going or you are going to be a statistic. For my money, I would plug everything in, tape or seal it all, secure the wires so they won't get in pools of water. It might be wise to connect the ground of the generator to the negative of your wiring system, but I can't swear to that.

I managed to start a fridge once off an inverter, but it was a 1200 or more watt inverter and huge very short wires to the battery....500 watts off a 12 volt battery would be 42 amps and youre going to have to run the ship's engine pretty fast to keep up with that or you'll have a dead battery in no time.

Schmaltz~Herring · 10-03-2007, 11:25 AM

I use it for shore power only, no considerations, it plugs into my cabin GFI outlet or plug it direct to SP with the adapter. The unit I have has a remote control to change temp,etc.

Trey1096 · 10-03-2007, 01:13 PM

As others have stated, evaporative type cooling works a lot better in environments that have a low ambient relative humidity.

The amount of water vapor air can hold decreases as the air temperature decreases. For instance, air with a temp of 50deg can only hold one third as much water vapor as air at 85deg. This means that, as you cool the air, either the relative humidity increases, or you pass the dew point.

The dew point is the temp to which air must be cooled (at a constant water vapor content and pressure) for saturation to occur. Once saturation occurs, the water vapor will condense out of the air. With evaporative cooling, you are increasing the amount of water vapor in the air while decreasing the temp. This makes the decreasing temp and the increasing dew point “race” toward each other. When they meet, everything gets wet.

Let’s say that, on an Orlando summer night, the ambient temp is 80deg and the relative humidity is 80%. If you didn’t increase the amount of water vapor in the air, you could only reduce the temp by about 5deg before you would reach the dew point. If you were using an evaporative cooler, the amount of water vapor would increase and you would reach the dew point faster. How fast would depend on variables such as the volume of the cabin and the temp of the water/ice used to produce the cooling effect. Even if you didn’t reach the dew point, the increase in relative humidity would work to offset any reduction in temp so you would most likely not “feel” any cooler.

In a house, you generally have a conventional HVAC system that is designed to remove water vapor from the air as the temp decreases. This feature would help remove the extra water vapor added by the evaporative cooler. This combination very well could produce a net effect of a more comfortable environment.

I hope this helps and doesn’t sound too much like an “engineering explanation.”

Trey

viogator · 10-04-2007, 09:36 PM

Thanks Trey.... that actually clears up a lot. Sounds like unless I grow gills, evaporating cooling is NOT the way to go on the water here in Florida.

It it great to see some of the innovative techniques for cooling small cabins though.... I think I will try one of those.

catfoiler · 10-05-2007, 08:57 AM

One more safety issue BUY a CO detector for your cabin!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Fishegg · 10-05-2007, 09:50 AM

Doesn't the orange tag on that cord say not to run the AC on an extension cord? Be careful with your electricity manangement.

Schmaltz~Herring · 10-05-2007, 10:16 AM

Quote:

Fishegg - 10/5/2007 9:50 AM

Doesn't the orange tag on that cord say not to run the AC on an extension cord? Be careful with your electricity manangement.

No [12 guage], when used on the boat it is plugged into a cabin GFI outlet which is wired to a 30 amp hubbell shore power inlet, the cord used at dockside is a standard 30 amp.