The research was conducted to examine the dispersion of pollutants ejected from a chimney a around three-dimensional rectangular building. Regarding the experimental study, the wind tunnel experiment comprises data acquired through the dispersion of continuous source tracer discharges (air seeded with glycerin particles) from a punctual source situated in a regular network of a building-like obstacle, and these data include measurements of mean velocity and turbulence parameters. The relevant data are followed using particle image velocimetry (PIV) to track various instantaneous and mean dynamic characteristics. Concerning the numerical study, the suggested model simulates both the dynamics and the heat transfer flow field using the overall mean three-dimensional Navier–Stokes equations with a Reynolds stress model (RSM) turbulence closure model. The findings of a deep comparison of turbulent flow and dispersion between a full wind tunnel experiment and the model predictions are reported. A high degree of concordance was obtained with the experimental flow and numerical simulation data. The detailed investigation, which included numerical and winds tunnel studies, was performed to evaluate the impact of wind velocity on the pollutant dispersion issued from a chimney around the building in their vicinity. The simulated mean flow results were checked against the respective wind tunnel tests, demonstrating for most flow positions be in good agreement. The results clearly showed how wind velocity influenced the environmental air flows and pollutant dispersal pathways. The results of this study show that the shape of the building and the resulting interaction between the wind structure play a determining factor in the distribution of pollutants around a building, thereby affecting the air quality in the various parts of the building. The work has clearly indicated that sophisticated CFD modeling can yield valuable insights for city planners when changes to the urban landscape are being addressed, so that appropriate design approaches can be checked according to environmental suitability criteria.