[srbell]

I have two of the Aircare evaporative humidfiers for my house. Seems they were around $120 each. Yes, they do have a wick in them (it's not really a filter) but that's what keeps it from putting all of the white mineral dust all through your house. The air blows through the wick taking the moisture with it but leaving the minerals behind. The more mineral-rich your water is the more often you'll need to replace the wick. I can get by with one wick each through the winter, or possibly two if used heavily, which would mean through a very long, cold winter in my case. Distilled water would eliminate the dust issue and make the wicks last pretty much indefinitely, but the cost would be prohibitive - many times more than just replacing the wicks. I replace the wicks when they have caked up with mineral deposits.