Four-sided air filter

Apparatus for filtering air comprising:

• a blower having an intake for drawing air and an exhaust for outputting air, said blower operating at a plurality of speeds;
• a housing for enclosing said blower, said housing having four apertures formed therein, said apertures configured in a rectangle enclosing said blower;
• four filter holders through which air is drawn by said blower, each of said filter holder operable to hold filter elements across said apertures;
• said filter elements comprising a filter material for filtering unwanted particles from the air and a filter frame for enclosing said filter material, said filter frame allowing easy replacement of the filter material enclosed therein;
• said filter elements interchangeably disposed within said filter holding means, such that filter elements can be easily replaced within the filter holding means;
• and
• a hinge top portion having means for directing the airflow out of said exhaust and allowing access to said filter elements within said filter holders.

Filter apparatus for holding a granulated filtering material comprising:

• two perforated panels having opposite edge portions formed normal to the face of said panels;
• side members each having an integral screw boss disposed along the length of said side members forming channels for engaging said edge portions of said perforated panels, said side members holding said perforated panels a predetermined distance apart;
• and
• a top member removably engaged to said side members by screws extending into the bosses to allow a user to fill the cavity formed by the perforated panels with granulated filter material, said granulated material having particle sizes greater than the perforations in said panels, such that a filter element is formed to filter air passing through said perforated panels.

A washable filter comprising:

• two washable electrostatic polyprophylene filter panels;
• a first frame holding one of said washable filter panels, said first frame having a leaf spring
• a second frame holding the other of said washable filter panels, said second frame having side members containing a charcoal filter material and a rim disposed about said side members;
• and
• said first frame operable to enclose said filter material within said second frame, such that said first frame fits within said rim only when said leaf spring is in a compressed position.