Ambient moisture can condense on electronics and promote degradation. In Florida some voting machines would register a vote for the wrong candidate because moisture fiddled with the sensors. Anything with a screen or a lens is prone to trap a haze of moisture inside. When I carry my laptop in my bag in the rain, I worry that the exposure to wet cloth, wet air, and possibly drops through the cooling vents keep the computer wet for hours.

Because waterproofing is difficult, we can minimize exposure to water by including dessicants. The dessicant should come with the device, integrated into the construction, and for long-lived devices the dessicant should be replaceable. If replacing a cheap silica dessicant package once a month, via an easily removable cartridge, extends the useful life of the device by a year, then it was well worth the cost and inconvenience.
-- Ketchupybread, Nov 09 2010

Just as long as you remember: DO NOT EAT the dessicant package. It's so easy to forget. [+]
-- Boomershine, Nov 09 2010


ah that reminds me of a story. (pours glass of port, sits in rocker)

When we lived in Japan, we celebrated an American Holloween on the Navy base. I bought Japanese candy which came in a plastic bag. There were dessicant packages in this collection. Because they were marked in Japanese letters I did not notice them at first. Wondering what it was, I opened and tried to eat, bleh. glass beads...

End of story
-- dentworth, Nov 09 2010


[bigsleep] That's brilliant!

(What do they put in packets of dessicant to keep it dry?)
-- spidermother, Nov 11 2010


[spidermother] Silica gel is the most common one found in the little packets, calcium chloride, and sodium chloride (salt) are also common desiccants.

The real issue here is the fact that when exposed to open air especially near a fan, they would become fully moist in relatively short time and probably wouldn't be able to lower the humidity in a computer for very long. Also it would take up significant space inside a crunched laptop.

Also you generally need to take them up past boiling point for the water to bake out. A cpu may get close enough to dry them siginficantly but I'm under the opinion that even a few hours exposed to a humid day would fill them and make the laptop no better.
-- metarinka, Nov 13 2010


//A cpu may get close enough to dry them siginficantly//Look at it backwards. It's an evaporative water-cooling system which gets its water from the atmosphere.
-- mouseposture, Nov 14 2010


Thanks, [metarinka]. However, I was merely attempting humour. When you buy stuff, they put packets of silica gel in there to keep the stuff dry. When you buy silica gel, what do they put in there to keep the silica gel dry? (On checking the first link, I found that [bigsleep] had already made that joke, and I had commented on it. Whoops.)
-- spidermother, Nov 14 2010



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