Filter monitoring apparatus for filter cleaning

A method for alerting a user to clean a filter, comprising:

• positioning a filter monitoring apparatus on a filter, the filter monitoring apparatus having an anterior module with a laser emitter and a posterior module with a photodetector, wherein the anterior module and posterior module are magnetically coupled on opposite sides of the filter;
• emitting a laser beam from the laser emitter through the filter toward the photodetector;
• maintaining an alarm circuit in an inactive state when the photodetector receives the laser beam;
• and
• activating the alarm circuit to generate an acoustic alarm and an alert indicator when dust accumulation on the filter blocks the laser beam from reaching the photodetector.

A filter monitoring system, comprising:

• a two-part housing configured to be installed on a filter, the housing comprising an anterior module and a posterior module that magnetically attach to each other with the filter positioned between them;
• a laser emitter positioned in the anterior module and oriented to direct a laser beam through the filter;
• a photodetector positioned in the posterior module to detect the laser beam when the filter is unobstructed;
• an alarm system comprising at least one of an acoustic alarm and an alert indicator;
• a wireless transmitter configured to send alert signals to a user device;
• and
• a control circuit that activates the alarm system and the wireless transmitter when the photodetector indicates that the laser beam is blocked by dust accumulation on the filter.