Distribution characteristics of indoor oxygen concentration under natural ventilation in oxygen-enriched buildings at high altitudes

Abstract

Diffuse oxygen supply is an important means to improve the indoor oxygen environment of buildings and ensure physiological and psychological health of immigrants in plateau areas. Existing research on oxygen enrichment strategies at high altitudes has mainly focused on confined spaces under mechanical ventilation, with few studies on the distribution of indoor oxygen concentration under natural ventilation in actual buildings. This study used a verified computational fluid dynamics (CFD) method to investigate the indoor oxygen distribution with practical consideration of natural ventilation at high altitudes. The results showed that the oxygen distribution under wind-driven natural ventilation was more nonuniform than that under buoyancy-driven natural ventilation, with the ratio of local oxygen concentration to overall-mean oxygen concentration, the k value, between 0.8 and 1.3 under wind-driven natural ventilation and between 0.9 and 1.1 under buoyancy-driven natural ventilation. The effects of meteorological condition and oxygen source position on indoor spatial oxygen distribution characteristics were explored with careful examination in human occupied zone under lying, sitting and standing postures. The results can provide implications for effective and energy saving design of indoor oxygen supply system in plateau buildings.