The process of global industrialization and urbanization has resulted in significant increases in air pollution, posing serious threats to both the environment and human health. In response to this complex and multiscale issue, Reynold-averaged Navier-Stokes (RANS) CFD simulations emerge as the most adept tool. Its cost efficiency, capacity to capture multi-scale phenomena, and suitability for parametric studies position RANS simulations as the optimal solution, surpassing the limitations of full-scale field measurements, laboratory-scale physical modeling, and the computational demands of Large Eddy Simulation (LES). Precise modelling of air pollution dispersion within the Atmospheric Boundary Layer (ABL) is crucial in the context of RANS CFD simulation. This paper aims to clarify the existing confusion in modelling ABL flows providing comprehensive guidance for both open regions and urban contexts. The study emphasizes the importance of obtaining fully developed equilibrium profiles as the initial state of ABL flow. We delve into the concept of horizontally homogeneous ABL, presenting a framework for its application and addressing challenges associated with realistic ABL modeling in CFD simulations. The objective of our research is to identify the most relevant and effective conditions from existing literature. We conduct an analysis and comparison of notable ABL boundary conditions and dispersion models within identical conditions and domains. This in-depth comparative analysis serves as a valuable resource for researchers and practitioners, affording nuanced insights into the optimal conditions for modeling atmospheric flows.