Automated fault detection and diagnostics (AFDD) serves as a powerful tool to maintain and enhance building energy performance. However, the implementation of AFDD techniques is restricted by the limited types of building HVAC equipment and systems developed for AFDD applications. Comprehensive data sets containing a variety of fault-free and faulty scenarios of common HVAV equipment and systems are in high demand. This study conducts a series of controlled laboratory tests designed to determine both fault-free and faulty performance of common HVAC equipment and systems in a well instrumented, monitored, and controlled operating environment. Three different HVAC systems are tested, namely, fan coil unit system, dual-duct VAV system, and fan-powered VAV system. This paper focuses on the dual-duct VAV system test, and presents the test approach, major results, and analysis. The dual-duct VAV system is tested in three seasons: summer, winter, and fall as the transition season and approximately 20 faulty cases are tested in each season. The fault types implemented include equipment faults, sensor faults, actuator faults and control faults. These faults cover the majority problems that could occur in a typical dual-duct VAV system. Preliminary comparison of the data patterns between fault-free and faulty cases are also discussed in the paper.