Improving the indoor air quality (IAQ) in naturally ventilated lecture hall with a single facade by solar chimneys

Abstract

Abstract In this paper, the indoor air pollution was investigated inside an educational building which contains air pollutants with elevated concentrations. A field study was conducted in a naturally ventilated, single-faceted lecture’s hall to evaluate the indoor air quality (IAQ). Both air velocity and carbon dioxide (CO2) concentrations were measured at the respiratory area level to compare these values with ASHRAE standard (62.01-2019). The computational fluid dynamics (CFD) 3D model was utilized to predict the air velocity, and CO2 concentrations, and to validate the measured air concentrations. The measured results fairly agree with the numerical CFD data with a 6.2% difference between both values. This paper deals with experimental work to study the effect of the cross-section area, the number, and the height of the solar chimneys. The results showed that using solar chimneys improved the natural ventilation in the hall and minimized the CO2 concentrations. Additionally, using the chimney cross-section area of 0.25*0.25 m, 0.30*0.30 m, and 0.40*0.40 to 0.50*0.50 m can reduce the CO2 concentrations to (3%, 6.2%, 6.4%, and 6.7%, respectively). While using three chimneys instead of only one, the ventilation flow rate increased from 61 to 70.9%. The effect of the height of the chimney on the average of CO2 concentrations inside the hall was examined. The modeled height rates (1, 3, 5, and 7 m, respectively) were improved to 26%, 33.6%, and 48.7%, respectively.

Keywords

• Indoor air quality
• Natural ventilation
• Carbon dioxide (CO2)
• Computational fluid dynamics (CFD)
• Lecture hall
• Solar chimney