Wednesday, July 7, 2010

DIY Evaporative Cooling

Ok folks here's a tip that might help if your ac unit is either broken, inefficient, too expensive to run or just plain non-existent.

You'll need a box fan or some other type of portable fan, some water, a large and preferably flat open container for the water, about one square yard of burlap fabric or other type of loose but absorbent fabric, (an old t-shirt with a bunch of tiny little holes cut in it will do in a pinch), and some duct tape.
Fasion your fabric piece so as to cover the intake, (sucking), side of the fan, leaving about a foot or so of excess extending at the top. Soak the fabric in water and wring it out so that it is damp but not dripping. Stretch it to cover the whole back of the fan and duct tape it firmly in place. Next, make some little duct tape loops and stick them on the bottom of your water container. Stick this container to the top of the fan and pour an inch or so of water into it. Take your damp cloth and submerge as much of the excess fabric as possible in the water. Now open a window and carefully place the fan (read, home made ac unit), in front of it with the cloth facing the window and the fan blowing into the room. (You may even have better results by just sticking the fan in the middle of the room, windows closed.) Turn it on and chill in the cool breaze!

How does this work?
As hot air is drawn through the moist fabric, some of its energy is absorbed by the water. This water evaporates and the cooled air is passed into the room. After the water has evaporated and left the cloth, capillary action, with an asist from gravity, moves more water down the fabric and the process continues, eventually depleteing the resevoir on the top of the fan. Now, while this won't cool your room to freezing temperatures, it can cool the room by a few degrees, bringing it down to a more tolerable temperature.

Try it. It might help!


Quick disclaimer:
Don't be a dummy and pour water into the fan. Dry your hands and all equipment before pluging it in. Be carefull with water around electricity.

2 comments:

  1. You should post some photos for us visual learners.

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  2. I have a seven part series documenting the process of building this swamp cooler from concept to operation. This unit uses very little electricity and a minimum of water with no ice or anything else. The parts list totals less than $100.

    I use this cooler on a daily basis in the southern desert, off the grid in temps well above 100 all the time.

    http://slabtech.site88.net/serendipity/index.php?/categories/2-cooler

    ReplyDelete