A single compact air cleaner unit includes a motor and fan assembly, a mechanical pre-filter, an electrostatic precipitator, a main filter cartridge which is easily removable and which contains both a synthetic mesh media with electrical charges embedded therein and a plastic screen impregnated with...http://www.google.es/patents/US5035728?utm_source=gb-gplus-sharePatente US5035728 - Air cleaner assembly
