Bests & Worsts Reviews from Amazon

I've had this vaporizer (or possibly an earlier model that looks just like it) for at least seven years. I think I paid about $21 at an in-person store. It still works just fine, and I've used it most winter nights ever since I got it. If it broke the first time I used it next winter, I'd buy another one right away. The way the unit works is that it runs electricity through the water between a pair of electrodes in a confined space, and the electrical resistance of the water heats the water to boiling. Steam boils out of the top of the confined space through a vent, and more water enters from the water reservoir. The water needs to be slightly salty (or have other dissolved minerals) because very pure water is too poor a conductor to allow enough electricity through the water to heat it to boiling. The key to making it work well is getting the quantity of salt right. Too much salt, and it generates steam too quickly; the room gets too warm, and it runs out of water part of the way through the night. Not enough salt, and it doesn't generate enough steam. The amount necessary depends on how the amount of dissolved minerals there are in the tap water. If the tap water has a lot of dissolved minerals ("hard) water, or the slightly salty water one gets after running hard water through a softener), it doesn't need much salt, and may not need any. If the tap water has very few dissolved solids (naturally "soft" water, rain water, etc.), one must add a comparatively large amount of salt. In addition to adding humidity to the room, it warms the air somewhat. Since one normally needs a humidifier only when heating chilly air, that shouldn't be a problem, but the added heat might be uncomfortable if the air is dry because one lives in a desert. Heating the water to boiling requires more electricity than other types of humidifiers (ultrasonic and evaporative), but it produces pure steam. By contrast, an ultrasonic humidifier produces tiny drops of water that evaporate quickly, leaving any dissolved solids floating in the air as dust that settles out everywhere. In an evaporative humidifier the dissolved solids are left behind on the evaporation fiber, eventually fouling it with crud. If there's any microbial growth in the water, a steam humidifier kills it as it boils the water, but an ultrasonic humidifier sprays it into the air with the water mist, and in an evaporative humidifier it grows on the evaporation fiber until it smells. One thing some people don't like about this type of unit is that black crud flakes off the electrodes and settles into the bottom of the water reservoir. (See photo.) It's harmless, but it looks icky. Some of the black flakes are probably part of the electrodes themselves, and if that's the case the electrodes will eventually erode away to the point that the unit stops working, but I haven't had that problem, and the unit is so inexpensive that I wouldn't complain if it did. -SS