A modular frame for use in air purification devices is described. In one aspect of the invention, a plurality of frame members are arranged in a linked stack to form a housing for components of an air purification device. The frame members are arranged to define a flow channel through which a fluid stream passes and to support components of the air purification device that receive the fluid stream. In another aspect of the invention, a plurality of rods are arranged to pass through the frame member stack. A first one of the rods serves as an electrical power source at a first potential and a second one of the rods serves as an electrical power source at a second potential. Electrical connectors are provided to electrically couple electrodes on selected components of the air purification device to their associated rods. In devices that utilize electrostatic filters, the electrodes that are connected to the rods may include the electrodes of the electrostatic filters. In devices that include ionizers or plasma chambers, the electrodes connected to the rods may include the discharge and/or receptor electrodes.