Application of Automated Fault Detection and Diagnostics For Rooftop Air Conditioners in California

The primary goal of the research described in this paper was to apply a decoupling-based fault detection and diagnosis (FDD) technique and economic assessment method to light commercial cooling and heating equipment in California. The paper describes the decouplingbased FDD methodology and the economic assessment method. The methods have been applied to a number of field sites. Detailed results are given for a single site and summary results are given for the other sites. About 70% of the investigated systems were impacted by faults and about 40% had more than one fault. Service was justified for about 40% of the units. The FDD technique was able to diagnose most of the existing faults. The estimated 10-year cost savings for FDD ranged from about $800 to $1700 per ton.