Venta Filter-Free Evaporative Humidifier

I've had the Venta LW25 for about 2.5 years now. It has been trouble free and works well humidifying the air and cleaning the air. You need to add the Venta water treatment, once every two weeks when you clean the unit. I simply "rinse" it out and use a paper towel or cloth to wipe it out. Once a season I use the Venta cleaner. It is a bit tough to remove mineral deposits, but otherwise it is very easy to fill, use, rinse. When you clean it after two weeks you can see the sludge in the bottom of the tank of debris it has pulled out of the air. For my house, which is forced hot air, a full tank usually lasts 40-48 hours unless it is extremely cold, then it lasts 24-36 hours. (other types noted below, even with larger tanks would be a max of 24 hours). We usually leave ours on the medium fan speed and it is a nice background noise. If it is really cold or if the unit ran out of water for a while, we use the high speed which still isn't too bad. I've used boiling water (dangerous & energy hog), cold air filter types (filters grow mold in a matter of weeks), and ultrasonic for years. I've been using various types of humidifiers for years (20-30 years) due to sinus and/or winter allergies. If I don't use a humidifier in winter, I also get bloody noses, which I haven't had since I've been using this unit, so that is a good sign that it is humidifying the air. I got tired of trying to clean the boiling water types and the energy bills. Looking at the cold air filter type, It can't be good to spread mold around the house and cleaning it was also troublesome and replacement filters are costly regardless of the brand. As for ultrasonic, they worked the best of the other three BUT they ruined several pieces of furniture and some wood flooring from their "white dust" mineral laden output. Granted the water in my area is mineral laden but I can't do much about that. I also found it to be a pain to clean it weekly, very tough to get into all the nooks in cranny's of the brands I've had. Of the three styles, I liked the Ultrasonic the most, but I can't live with the damage they have done. As for the Venta - it is much easier to refill, I use a pitcher, easier to clean than any of the other styles, and I have to fill it less often because the tank holds more water. Unlike other types, it automatically shuts off when it is out of water. YES it is more expensive than a lot of other humidifiers on the market, but in the end both my wife and I are very happy with the unit. Also, worth considering is there are no filters to replace, so if you do the calculations over a few seasons, the VENTA starts to look pretty competitive. You need to purchase the water treatment, which a bottle lasts most of the season, and the cleaner solution for use once or twice a season. For a season, these both cost less than one set of filters which typically last 2-4 weeks. The cold air filter type humidifiers are kinda like the Razor blade business, they often give a away or sell the handles cheaply, but they get you with the replacement heads (filters). All in all a great unit. Good size water tank for extended use, no filters to replace, comparably easy to clean. Obviously I'm a fan of the VENTA 25 units. I recently purchased the larger VENTA 45 for the living room!