First classifies faults in ventilating systems, consisting of fans, ducts, dampers, heat exchangers, and controls. Then reviews two forms of steady state parametric models for the electric power used by ventilation system fans and proposes a third, that of correlating power with variable speed drive control signal. The models are compared on the basis of prediction accuracy, sensor requirements, and ability to detect faults.

KEYWORDS: ventilation, failure, energy consumption, monitoring, calculating, models, electricity consumption, fans.