Computational fluid dynamics (CFD) modelling of air flow field, mean age of air and CO₂distributions inside a bedroom with different heights of conditioned air supply outlet

It was revealed in a previous related study that for an air conditioning (A/C) system used in a sleeping environment, the height of its supply air outlet would significantly affect its ventilation performance in terms of effectiveness. To further examine the underlying reasons of the differences in ventilation performance, the air flow field, distributions of mean age of air, air change efficiency and distributions of CO2concentrations inside an experimental bedroom were numerically studied using CFD method under five different settings, where its supply air outlet was positioned at 5 different heights. The study results suggested that positing a supply air outlet at a lower level was effective in both saving energy and removing the exhaled CO2in a breathing zone, and when a supply outlet was positioned at a higher level, less CO2was removed from the region near the mouth of a sleeper.