Study on Normalized Concentrations in an Occupied Zone in Office Space Optimization of Fresh Supply Air Flow Rate and Analysis of Energy Consumption

The values of the normalized concentration in the occupied zone (Cn) in an office space arecalculated by CFD for five different ventilation systems and the minimum ventilation rate which maintains the average concentration in the occupied zone under the regulated value is analyzed. Energy consumptions associated with the change in ventilation rate are analyzed. In this analysis, for most ventilation systems, the value of Cn is around 1.0, but for large circulation flow ventilation systems it changes greatly depending on the supply inlet velocity and temperature. In the case in which the Cn index was applied, the maximum energy consumption decreased by about 4 %, compared with the case in which perfect mixing conditions were assumed.