Patent ID: 7878007

Claim:
A method of monitoring an air-conditioning unit, the method comprising: sensing inlet temperature and outlet temperature of a fluid passing through an air-to-air heat exchanger associated with the air-conditioning unit; sensing air temperature at an air inlet side of the air-to-air heat exchanger, wherein air flows across the air-to-air heat exchanger from the air inlet side to an air outlet side thereof; automatically determining, by a processor, at least one of airflow rate through or heat removal rate of the air-conditioning unit employing at least in part effectiveness of the air-to-air heat exchanger, the automatically determining comprising automatically determining effectiveness of the air-to-air heat exchanger employing at least the sensed inlet temperature and outlet temperature of fluid passing through the air-to-air heat exchanger, and the sensed air temperature at the air inlet side of the air-to-air heat exchanger; and outputting the determined airflow rate through or heat removal rate of the air-conditioning unit.