Bionaire humidifier model:bcm7309cm How to clean the air filters?

"You should change your furnace filter once a month in the winter season and your central air filter once a month during summer months.
If you run your heat or air every day and night, have pets, or your home collects a large amount of dust, you may need to change your filter more often during very hot and very cold months.
If you use disposable filters, it's really not worth vacuuming them to reuse them. They are inexpensive enough that you should replace them instead.
Disposable filters don't work as well after only being vacuumed and they are usually in a cardboard frame and therefore don't wash well.

Before you take out the filter, however, vacuum the outside and around the filter encasement. After you remove the filter, you should vacuum behind it, too, to catch any stray dust and particles.
Replace disposable filters with new ones."

(http://www.mrscleanusa.com/en/cleaning-tips/tip/cleaning-air-filters.html)