Ultrasonic Humidifiers
Fog Output


So many people have asked me questions about ultrasonic humidifiers, I figured I'd better put up this page to cut down on my E-mail!

Ultrasonic humidifiers (also called cool mist humidifiers) are electric, table-top, home appliances for adding moisture to the air. You can buy them at stores like Sears and K-mart for about $40. You can also find used ones at garage sales and thrift stores for as little as $5. They're usually rectangular boxes about 7" by 9" by 14" with a couple of dials, a removable water tank, and a nozzle on top. They work great for small effects like a witches' cauldron or a fog-breathing pumpkin. You fill them with water and they create a cold, white smoke of water mist which tends to sink and run along the ground. The fog disappears after drifting a foot or two from the humidifier. Store-bought fog machines (and my home made fog machine) produce fog which hangs in the air for much longer but doesn't sink at all.

Ultrasonic humidifiers usually have a humidistat to shut them off at a certain humidity. This can be a problem in haunting applications. The humidistat on every humidifier I've seen can be disabled by simply shorting (connecting a wire between) the humidistat's two wires. Do this at your own risk, of course.

Fog fluid won't work in ultrasonic humidifiers, but I've heard that adding 5% glycerin to the water can make the fog hang in the air longer. (That's one part glycerin to nineteen parts water.) Fog fluid is about 1/3 glycerin (or a similar chemical) so you'd add 15% fog fluid to get the same effect. (That's three parts fog fluid to 17 parts water.) I haven't tried this myself. You can get small amounts of glycerin at a drug store, or larger amounts from restaurant supply companies.



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