The air in Beijing is something you try not to think about. It is 90% of the time horribly dirty and polluted, in summer it is humid and in winter it is dry as hell. If in winter you don’t use a humidifier you get electric shocks from anything you touch and your airways slowly evolve into (dirty) rubber tubes.
But humidifiers are not that easy to use. The worst are those “electronic” ones, so easy and cute but they spray-paint everything inside out with a white film. They love computer screens, plastic bags, CDs, anything. I just wonder how any CD/DVD reader can survive. You open cupboards and even inside you find the white mist.
I tried everything, boiled water, “distilled water”, anything but it seems you still have more than enough minerals in the water to go and cover your CDs.
Best is still the evaporation type where most of the calcium stays inside and the air is also filtered. They consume lots of water when they are well maintained – cleaning them is a big job however.
The Made in Switzerland winner of the bunch: the two DEFENSOR AG (model 500-V) I have for over 25 years. Type: evaporation; through a pump the water drops on the filter where the air is forced through thanks to the fan.
They still look “new” except for the outer covers – thanks to thorough maintenance. The filters are the weak point: they must have beaten all records, 20 years of use while I guess they need to be replaced every one to two years. Maybe I should see if I can still buy them somewhere. Never found an acceptable substitute material.
The only technical problem: one switch died so I short-circuited it and need to unplug it to switch off. The filters have become too thin and I use some small wires to help them hang in the right position.

Cleaning method: the big maintenance is done by removing the fan, cleaning the inside of the pump housing (use pipe cleaner); over 1 L of strong vinegar (> 30%) mixed with warm water, let the pump work for at least 30 min. Filter is soaked in the vinegar separately and washed out innumerous times (the amount of dirt coming out is unbelievable). The whole unit is thoroughly cleaned afterwards. Like this all calcium and dirt is removed. No scratching.
The only other surviving humidifier is Chinese, brand YADU, model YC-E430B. YADU is now Exclusive Supplier for the 2008 Olympics. The model works by boiling water on a small plate and then the mist is blown out through a small fan. I am sure YADU will come up with a more “complicated” technical explanation but that’s basically how it works.
Weak points of the design: most of the minerals and calcium go out with the mist and the system has no air filter as such. Otherwise, very simple to use and small.
The humidifier is one of the many equipment I received, dumped because they either work poorly or people have no clue how to handle them.
The YADU at first only needed a good cleaning and worked well till it stopped “blowing”. Opening the unit was a bit hard, they use special screws so you can’t open it, well I mean OTHERS can’t open it. The unit is neatly built and even has a fuse inside. The verdict: the electric motor seems to heat up a lot and the lubricant for the rotor axle simply disappeared, so the rotor stopped turning. I dismounted the motor, cleaned all parts, put some grease and … back in business. Yadu needs to address this weak point. For most Chinese consumers they would simply throw away the unit and not think about repairing.
For the water I use hot tap water – cooled down of course. In the hope most of the calcium is gone already. The inside can get very dirty very quickly, with a glue-like deposit and the usual calcium. Cleaning: hot water and the usual vinegar. And careful cleaning up.
At least it works OK and somehow… it’s cute.

Anybody has a tip for the water, like some pre-treatment? Could not find anything. Of course I can buy one of those horribly expensive models in Lufthansa Center (with yearly replacement of all kinds of parts…). No plans however to do so. I’ll stick with the vinegar (“dirt cheap”).