How To Build An Energy Free Water Chiller

The Solution
As a maker of twelve volt swamp coolers for myself and many others, the answer to this problem seemed fairly simple, Some sort of swamp cooling concept which instead of producing large amounts of cool air would produce cool water in a quantity which would be adequate for bathing or even cooling a small space. So After some thought I rounded up my materials.
I started with a small barrel shaped bucket which I had found and equipped it with:
a swamp cooler float so that a larger water source could continuously feed our smaller chiller
An aluminum tube which was created out of flat sheet aluminum
Some cooler pad material
a small computer cpu fan which operates at 1/4 amp at 12 volts
a piece of aluminum sheet metal to fasten our fan to.
Some foam to insulate the bucket with
The finished chiller is wrapped in foam to insulate its contents

Why this works
The swamp cooler material which is inserted into the cooling tube reaches into the water about 6 inches. It is kept damp by what is called a wicking action whereby the dry cooler pad material soaks the water from the tank and saturates itself creating a damp swamp cooler pad. Though you can leave the computer fan out it does help our water chiller to work more quickly and efficiently by sucking air down the tube and across the top of the water evaporating water more quickly. Your swamp cooler float should be set so that there is at least an inch or 2 of air space at the top of the tank.
As the water slowly evaporates from the pad material it creates a cooling effect which is also transmitted to the aluminum tube. This in turn cools the water in the tank through thermal conductivity .
The lower the input temperature the lower the output temperature, above freezing level of course.
If a larger tank is used a heat exchanger can be used inside the tank to cool another fluid such as oil or glycol which in turn could be used to cool an enclosed box creating a no power or low power form of indoor refrigeration. A simple radiator placed in the tank with water tight outlets and hoses should do the trick. In non temperate zones temperatures could conceivably be produced near freezing by using a highly saline solution for your input tank.
In my working unit we painted the input tank of water white to reflect heat and lower the input temperature from 130 degrees to 100. Exiting the chiller the water was 80 degrees. A total drop of 50 degrees Fahrenheit.
A simple open tank does the same thing but in this unit I seem to get lower temperatures with less water evaporation. Something which is important when you are moving hundreds of gallons of water by truck.
I had a great deal of fun constructing this project, produced a working system and its applications can be as varied as your imagination.

Build a twelve volt swamp cooler

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