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Machine Condenses Drinking Water Out of Thin Air
longacre writes "A new $1,200 machine that uses the same amount of power as three light bulbs promises to condense drinkable water out of the air. On display at Wired Magazine's annual tech showcase, the WaterMill 'looks like a giant golf ball that has been chopped in half: it is about 3ft in diameter, made of white plastic, and is attached to the wall. It works by drawing air through filters to remove dust and particles, then cooling it to just below the temperature at which dew forms. The condensed water is passed through a self-sterilising chamber that uses microbe-busting UV light to eradicate any possibility of Legionnaires' disease or other infections. Finally, it is filtered and passed through a pipe to the owner's fridge or kitchen tap.'"
Actually, it can get quite humid in the desret. I work with folks who have spent a lot of time in Saudi Arabia and in such places and they report that it is very humid in the summer time. The reason it doesn't rain is that there is no cold dry air masses that come down to mix with the hot humid ones.
There are some places this might be a very nice appliance.
Kevin
The problem with that is in order to be killed by the UV light (and it doesn't actually kill the bacteria, just scrambles their DNA so badly that they can't successfully reproduce) the bacteria has to be exposed to it.
I'm assuming you got some nice fuzzy mounds in pretty colors, all very opaque. Exposing those mounds to UV light mutates the surface bacteria so badly that they can't reproduce, but you've still got millions upon millions living beneath that one layer in ignorant bliss because their brethren above them absorbed all the UV radiation, sparing them.
The reason UV exposure works better in water is because water is clear and any bacteria that is present is not masked by... well... anything. It even works in fairly turbid water, assuming the water is agitated while being exposed to the UV so all areas get equally exposed.
Sorry to poke holes in your 8th grade fun... but that's what you were observing, not the failure of UV light to kill things.