Computational Fluid Dynamics Analysis of Air Circulation and Thermal Comfort in a Lecture Room

Abstract

This study presents a Computational Fluid Dynamics (CFD) analysis of air circulation and thermal comfort in Lecture Room D58, Faculty of Engineering, Baze University, Abuja - Nigeria. The purpose of the research was to evaluate the effect of Air Conditioning (AC) units’ placement on airflow distribution and temperature reduction. This was in order to determine the best possible locations of the AC systems for effective indoor thermal comfort in the lecture room. A three-dimensional model of the lecture room was developed using ANSYS Design Modeler, and six different AC placement configurations were simulated in ANSYS Fluent. The simulations solved the Navier–Stokes, continuity, and energy equations using appropriate turbulence models to predict airflow velocity and temperature distribution. The number of AC units (two and four units) and their vertical positions (2.8 m and 3.4 m above the floor) were varied in the six cases. Results showed that the initial room temperature of 33°C was reduced differently across the six cases. Case 2 on the YZ plane with two air conditioners positioned 2.8 m from the floor achieved the highest temperature reduction, lowering the room temperature from 33°C to 17°C (a 16°C decrease). Similarly, air velocity distribution in Case 2 was more uniform across the occupied zone compared to other cases. On the other hand, Case 1 on the YZ plane with two air conditioners positioned at 3.4 m from the floor and Case 6 on the XY plane positioned also at 3.4 m from the floor showed poor circulation with limited temperature reduction. Meanwhile, the cases with four AC units did not produce proportional improvement in comfort despite increased airflow. The study demonstrated that AC placement and inlet height are more critical than the number of units for effective cooling. It also provided insights into optimizing interior air quality and thermal comfort for lecture environments by ensuring adequate space between the AC units and top of the room.