Patent ID: 7713339
Filing Date: 2010-05-11
Classification: B01D,Y10S

Abstract:
1. An air filter monitoring system for indicating when to clean or replace a flexible air filter, the air filter monitoring system comprising: (a) a pleated flat-panel air filter having a peripheral frame and an interior filtering region; (b) a fixed support structure for receiving the air filter and maintaining the perimeter of the filter frame in a generally fixed position while allowing the interior filtering region to flex in response to air flow through the filter; and (c) a filter change indicator having a predetermined bias force, the filter change indicator including a housing, a position sensitive electrical switch arranged in the housing, a filter engagement member arranged to actuate the switch, and a biasing member arranged to resist a force applied to the filter engagement member by the interior filtering region upon flexing of the filter, wherein as the interior filtering region flexes in response to air flow through the filter, the interior filtering region exerts a force on the filter engagement member that increases with the degree of clogging of the filter and, when the predetermined bias force is reached, the filter engagement member triggers the switch to notify a user to clean or replace the filter.