Patent ID: 6225907
Filing Date: 2001-05-01
Classification: F24F,G05D

Abstract:
An incipient failure indication apparatus for an environmental control system, said system controlling the temperature of the air in a living space, said system including a heat exchanger through which air flows and a temperature control thermostat, said thermostat located in said living space, said apparatus comprising:an indicator mounted substantially adjacent to the thermostat, said indicator including an alarm and a control board, said alarm in communication with said control board, said control board in communication with the said thermostat, said alarm comprising one of a visual indicator and an aural indicator for attracting the attention of a person in said living space to said indicator upon activation of said alarm;a first temperature sensor disposed on the upstream side of the said heat exchanger, a second temperature sensor disposed on the downstream side of the said heat exchanger, said temperature sensors respectively sensing the temperature of the air on the upstream and downstream sides of the heat exchanger, said first and second temperature sensors in communication with said control board, said control board having a comparator which compares the temperatures sensed by said first and second temperature sensors, and an activator for activating said alarm in response to a determination by said comparator of a difference in temperatures sensed by said first and second temperature sensors which is one of less than and greater than a predetermined value.