Ventilation systems constitute an important piece of the industrial facility ecosystems. Creating proper working environmental conditions for humans is crucial, especially in hazardous sites with presence of various gases, such as underground mines. Combined with the vast amount of space to be ventilated in large mines, designing and maintaining such a system is challenging and costly. To alleviate these issues, the EIT-RM project VOT3D (Ventilation Optimizing Technology based on 3D scanning) proposes conducting advanced airflow modeling in the underground tunnel networks, utilizing computational fluid dynamics (CFD) simulations, modern surveying and 3D modeling approaches to reverse engineer a reliable geometric model of the mine and estimate the 3D airflow field inside it. In this paper, we present the challenges to be solved in this task and the proposed workflow to address them. An example related to an active industrial mine in Poland is reported as a basis for performing experimental data processing using the full, highly automatized procedure. Developments and results of underground mobile mapping (with a drone and a handheld system), point cloud processing and filtering, surface reconstruction and CFD modeling are presented. The detailed results of airflow field estimation show the advantages of the proposed solution and promise its high practical usefulness.