INVESTIGATING INDOOR AIR QUALITY AND THERMAL COMFORT USING DIFFERENT VENTILATION SYSTEMS UNDER IRAQI CLIMATE

Abstract

Computational Fluid Dynamics (CFD) of indoor environment as well as quality considerations are important element in the study of energy consumption, thermal comfort and indoor air quality in buildings. This paper investigate a comparison work between impinging jet, displacement, and mixing ventilation systems for an isothermal and non-isothermal ventilated room for Indoor Air Quality (IAQ) and thermal human comfort under Iraqi climate. For IJV system, draught discomfort is the issue of most concern since it supplies cooled air directly to the occupied zone. This study investigated a number of factors influencing draught discomfort and temperature stratification in an office environment. The considered factors, supply airflow rate and supply air temperature. RNG K-Ɛ turbulence model was used with the turbulent flow. The second aspect included numerical analyses by adopting ANSYS FLUENT15 code to generate simulation models. A square shaped air supply device was used with [0.1 times room height (h)] outlet terminal height from the foot level end. The IJV system proved more efficient than displacement and mixing ventilation systems. The Air Distribution Performance Index (ADPI) obtained for an isothermal and non-isothermal ventilated room adopting IJV system gave best values (0.80, 0.83) respectively compared with the other two ventilation systems.