HVAC system configurations: an energy aspect

This paper studies the energy implications of HVAC system configuration by analysing energy balance and psychrometrics of typical and innovative systems. Three criteria have been established: (1) the ability to minimize outside air load; (2) the ability to eliminate simultaneous cooling and heating, and use mixing effectively; and (3) the availability of inter-zonal airflow. Configurations that meet these criteria would be able to deliver the desired indoor air quality with reduced energy consumption. The performance of nine 2-zone system configurations, including single-duct, dual-duct, fan-coil-based variations, and other specialize systems in the literatures, have been analysed for a number of operational conditions. The results confirmed that fan-coil-based configurations with inter-zonal airflow paths perform better than other configurations. The conclusion of this study may be used as a guideline to multi-zone system designs.