Teardrops n Tiny Travel Trailers

I was doing a search on portable swamp coolers and came across this:



Its way expensive but it looks like it would be pretty easy to build. I'm thinking you could hang something like this over a window and blow cool air into the cabin. I'll stow it on my tongue when not in use. Best of all, it would be 12v so you could use it when boondocking. Does anyone have any idea how big an area would need to be covered with cooling mat in order to cool a tear? (Yeah, yeah I know, it won't work when its humid but its not humid in Colorado.)
Bruce

I played around with a home made one in 90 deg heat. I used an ice chest and a small 110 volt fan. One gallon of ice (8 lbs) cooled the trailer from 90 to 75 in about 3 hours. Then the ice melted. My trailer is a 5 by 10 insulated with a vent on the roof. Of course it doesn't helpthat I happen to be in the HUMID south.

Dan

No ice with this one. It works by flowing water down an aspen pad and blowing air across it. I'm thinking that 400 square inches of pad area should be enough.
Bruce

It looks nice do you have a link?

Here it is but hold on to your hat when you see the price.
Bruce

Thanks Bruce I will look and hope I don't pass out

I just started building a swamp cooler for my trailer. A few evenings is all it takes. I based it on the design at http://www.outbackteardrop.com/body8.html. My cooling mats are about 200 sq. in. Hopefully that's enough but if not, I'll just make them bigger. So far, I'm about $35 into the project and I don't forsee any more expenses--but you never know.

Water pump - $18 12v Attwood marine bilge pump, model V500
3/4" aluminum C channel - $10 (used about 4 of 8')
Switch & power connector - 5$
Plastic Tubing - $2
Container - scrap wood sealed with epoxy
PVC pipe & fittings - scrap
2 PC fans - scrap
wiring - scrap

The specs for the one you've pictured say it is 11.5 inches tall by 17 inches wide. Leaving about 3 inches for water at the bottom and some corners in the box, the biggest pad they can have is likely about 8x16 or 128 square inches. This assumes that the pad and its output grate are on the side opposite the fans. They claim the pad they are using in one of the coolers is 8 inches thick so it's not so much surface area as pad volume that matters.

I too am experimenting with building my own 12v swamp cooler based on the Outback design and will post when I get one done and tested.

I couldn't be happier with mine although it was more expensive. Has no pump so it uses low amps .07 on low here is the link www.swampy.net I have the MW1.

I picked up a bilge pump today at the marine store. I have a couple of pancake fans I can use so I just need to get some filter media and away I go. I have a plastic container I can experiment with. Please post some pics if you're building one too. I found some here. I'm going to start out with 144 square inches of pad area (just because its an easy number for me to remember) and work from there.
Bruce

Just an FYI, they sell the Attwood V500 bilge pump locally at Walmart for $10.00. I believe that this will be way too much water going over the pads and will have to be cut down some either by lowering the voltage to the pump or by putting a hole in the hose near the pump so most of the water does not go up to the top of the pad(s). I base this thought on my home swamp cooler having 5460 square inches of pad (4 sides, each 35x39) and only using a 360gph pump (for coolers up to 7700CFM).

I have the Attwood V500 but also ordered some smaller pumps today:

http://www.mainlandmart.com/aquapump.html

I ordered one each of the 85gph and 46gph 12v pumps. They are actually 110v with transformers that supply 12v. No word on the site about power consumption so I'm going to test all three pumps to see which one works best.

Since I don't have any 12v fans lying around I ordered some from:

http://www.allelectronics.com/

Search for "fan" and you'll see all kinds. $6.00 shipping for any order. I got two each of the 120mm CF-152, the 80mm CF-217, and the 120mm CF-153. I'll likely make a few different coolers and mix/match the fans, pumps to see which combinations I like.

BTW, if you're going to place an order with All Electronics and you don't already have one, I got a very nice fuseblock from them for $4.25 I'll use in one of my tears. It is only a circuit board so needs to be mounted in an insulated box. I'll probably use a plastic lunchbox.

http://www.allelectronics.com/cgi-bin/category.cgi?category=search&item=FHP-34&type=store

bdosborn wrote:Here it is but hold on to your hat when you see the price.
Bruce

Tupperware certainly is expensive these days I see.

samstoybox wrote:Just an FYI, they sell the Attwood V500 bilge pump locally at Walmart for $10.00. I believe that this will be way too much water going over the pads and will have to be cut down some either by lowering the voltage to the pump or by putting a hole in the hose near the pump so most of the water does not go up to the top of the pad(s). <snip>

That was the conclusion I came to after I ran the 360 GPH Real pump I got yesterday in a bucket. I'm going to look at some options for reducing the voltage but will probably go with a smaller pump like the ones you posted the links to since it seems like they would draw less current anyways. Thanks for the tips and keep us posted on your progress.
Bruce

A trickle of water is enough - you just want to keep the media wet.

I remember as a kid seeing simple wooden frames filled with spanish moss - sitting in the open windows so the breeze would do it's work. Just pour a cup of water over the moss periodically. This was in Lousiana. Something like this could work mounted to the trardrop's window.

Also back then in our house (Alabama), we had window units that looked just like AC units, you pulled a tray out to add water to the media (some sort of straw). Even in humid Bama they did work to some degree.

Here's some pictures of tonights mockup: the Franken Cooler:





My preliminary conclusions:

- 360 gph is *way* too big of a pump. 50 gph would be more like it. There's a Y bypass in the feed to the pads (its below water in the picture), part of the pump intake is blocked and its still way too much water. If I open the end of the tubes to the pads its about right. I think a channel across the top of the pad with holes in it would leak about the right amount of water.

- The pads need to be tight to the sides so there aren't any air leaks or air will just flow around the pads in the path of least resistance.

- Its 76F here tonight and there isn't much cooling going on. I need to try it when its hot outside. I can't tell much difference between the air from the cooler and just fans running. I'll try it with a thermometer tomorrow.

- The whole setup is drawing less than 2 amps at 14.1v (battery is on the charger).

- The plastic bin that I got doesn't cut very well. It fractures easily.

- There's no way I'd run this thing inside the trailer. The pads leak. Not a lot, just enough to make a mess. I'll need to duct it into the trailer somehow, probably a duct to the window for now.

- 200 CFM seems like its plenty of air. I'll make sure and switch the fans separately.

-Total cost so far ~$50.

More to come...
Bruce