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1. A clogged filter detector comprising:
an infrared transmitter with an aperture diameter of between 5 and 10 mm, said transmitter having a peak relative output intensity, that emits a beam of electromagnetic radiation; a silicon receiver sensor, having a peak relative sensor sensitivity near the peak relative output intensity of the transmitter, that produces an electrical current when contacted by electromagnetic radiation, and where a sensor reading is based on the electrical current produced; a transmitter bracket connected to the transmitter, where the transmitter bracket secures the transmitter such that the beam of electromagnetic radiation contacts a filter at a measurement point, and where the transmitter bracket secures the transmitter in a position that is misaligned with an air flow through the filter at the measurement point; a sensor bracket connected to the sensor, where the sensor bracket secures the sensor in a position that is mis-aligned with the air flow through the filter at the measurement point, and where the sensor bracket secures the sensor in the path of the transmitted beam of electromagnetic radiation in a position such that the transmitted beam of electromagnetic radiation passes through the filter between the transmitter and the sensor; a controller that controls the transmitter such that the transmitter is alternatively in a transmitting mode having an associated transmitting mode time period or a variable length dormant mode, and where the transmitter emits a predefined number of multiple pulses of electromagnetic radiation during each transmitting mode time period, each pulse having a peak voltage and a voltage sag and generating a sensor reading, each transmitting mode separated by a period of inactivity in the variable length dormant mode where the controller shortens the time between variable length dormant modes based at least in part on instruction from one or more processors that the filter is nearing a clogging level; and a non-transitory tangible media containing software or firmware encoded thereon for operation by the one or more processors, wherein the one or more processors reduce the impact of background noise reflected in the sensor readings from a single sensor by determining an average sensor reading value for the transmitting mode time period based on the sensor readings from the single sensor associated with the predefined number of multiple pulses within the transmitting mode time period, and wherein the determination of whether the filter is nearing the clogging level is based at least in part on the average sensor reading value from the transmitting mode time period.
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