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 nonisothermal
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-? 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.