Healthy indoor air quality
Buying guide for home air filters in furnaces - HEPA, SMART or standard?
...particles, and you won't have much luck washing paper.
Having said that, there are specialist manufacturers with product that might be worth taking a look at - anyone who has tuned a car will know the name K & N for example, but did you know that K & N also do a range of permanent and washable furnace filters? ...
