Effect of common faults on the performance of different types of vapor compression systems

•Studied systems differed by design, compressor, expansion device and refrigerant.•Effect of faults on system capacity, COP, and SHR may differ between systems.•The expansion device has the strongest effect on performance under common faults. The effect of faults on the cooling capacity, coefficient of performance, and sensible heat ratio, was analyzed and compared for five split and rooftop systems, which use different types of expansion devices, compressors and refrigerants. The study applied multivariable polynomial and normalized performance models, which were developed for the studied systems for both fault-free and faulty conditions based on measurements obtained in a laboratory under controlled conditions. The analysis indicated differences in responses and trends between the studied systems, which underscores the challenge to devise a universal FDD algorithm for all vapor compression systems and the difficulty to develop a methodology for rating the performance of different FDD algorithms.