Living in Arizona, I am very familiar with evaporative (swamp) coolers.
They work very well, IF the relative humidity is 40% or below.  They work
on constant air exchange, so if you put one in the middle of an enclosed
space, it will only work for a few minutes, until it raises the humidity
above 40%.  They must take outside air and blow it into the area to be
cooled, through the water saturated pads.  There must be another opening in
the cooled area to allow the air to escape.  On a house, that means you
turn on the cooler on the roof and open a few windows.  A vehicle isn't the
best place for them, but on a house, a good sized one will push 5000 CFM of
air into the house, and cool it as much as 40 degrees (f).  The only
electricity used is running the fan, so they cost MUCH less to operate than
refrigeration (what you Easterners call "air conditioning").

Bill (SE Arizona) (Bill@freeholder.com) HTTP://www.freeholder.com
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