Energy savings potential of passive chilled beams vs air systems in various US climatic zones with different system configurations

The energy savings potential of passive chilled beams in various climatic zones is analyzed in this study. A passive chilled beam model, developed based on full-scale experiments, is used as a system module in a whole building simulation tool to account for the convective and radiative effects of passive chilled beams. The model was validated with measurements from a field study in an open plan office equipped with multiple passive chilled beams. In addition, a parallel field study in an adjacent identical office space equipped with an air (VAV) system was conducted to compare the resulting energy consumption with the two systems. To further study the energy savings potential and indoor thermal conditions with passive chilled beams, four different chilled beam system configurations, combined with a parallel variable air volume system, were studied using the whole building model in different US climatic zones. The results showed that using a dedicated outdoor air system, or a separate chiller for the passive chilled beams, or a desiccant wheel after the cooling coil may result in significant relative energy savings depending on the location. The last option proved to be the most efficient, providing up to 12% for hot and humid climates and up to 20% for hot and dry climates –compared to a conventional variable air volume system. Finally, the radiative-to-total cooling effect of passive chilled beams varied between 7% and 8% and has only a small impact on energy savings and indoor thermal conditions.