Thermal environment and air quality in office with personalized ventilation combined with chilled ceiling

The thermal environment and air quality conditions provided with combined system of chilled ceiling and personalized ventilation (PV) were studied in a simulated office room for two occupants. The proposed system was compared with total volume HVAC solutions used today, namely mixing ventilation and chilled ceiling combined with mixing ventilation. The objective of the study was to evaluate whether PV can be the only ventilation system in the rooms equipped with chilled ceiling. The room air temperature was 26 °C in cases with traditional systems and 28 °C when PV was used. PV supplied air with the temperature of 25 °C. PV improved thermal conditions and was up to nearly 10 times more efficient in delivering clean air at workstations than mixing ventilation systems, which resulted in strong protection of occupants from the cross-infection. In the room space outside workstations no substantial differences in thermal environment were found between studied systems. The room air mixing with PV working alone was at the same level as with mixing ventilation. No substantial differences in contaminants' concentration distribution and air-change effectiveness were found between the studied systems in the occupied zone outside workstations.