Abstract: A filter cartridge for a standalone point of use water purification device includes tandem first and second flow passageways containing flowthrough filter media that cooperate to provide opposing flow directions in the first and second flow passageways that reduce, if not eliminate, channeling, and provide self-wetting of the flowthrough filter media contained in the tandem first and second flow passageways, eliminating the need for post-use wetting steps.

Abstract: An electrostatic room air cleaner includes a housing having a given profile and a plurality of electrostatic precipitation collector units arrayed in the housing with a common fan to circulate room air through the plurality of electrostatic precipitation collector units simultaneously. A total clean air delivery rate is delivered that is determined as the arithmetic sum of the clean air delivery rates of the plurality of electrostatic precipitation collector units arrayed in the housing of given profile. The greater the number of units arrayed, the smaller may be their size, and the easier they are to handle, maintain and replace.