Abstract: A self-contained electrostatic air filter assembly having two hinged rectangular frames into which is disposed rectangular polyester/wool filter dielectrics with a conducting charging screen in between. The polyester/wool dielectrics are charged through the conducting screen by a high voltage power supply having a low source resistance. The high voltage supply having a small source resistance is integrated into the air filter assembly and connected electrically to the conducting screen. High voltage is quickly dissipated from the screen and dielectrics when the unit is turned off by a specially designed bleeder resistor. As an air mass is forced through the filter, particulates in the air are removed electrostatically quickly and efficiently by the charged polyester/wool filter material. The air filter assembly has been shown to have a high particulate capacity.