Computational fluid dynamics (CFD) methods were used to analyze hydrogen leakage in a semi-closed ventilation facility. The goal of the research was to apply numerical simulations to verify hydrogen distribution in the semi-closed space using the commercial STAR-CCM + code and to compare the simulation results with experimental results. Experiments were conducted in a container with the dimensions 12.11 m x 2.39 m x 2.34 m. The experimental facility represents part of an underground mining tunnel. In the study, different combinations of hydrogen release pressure and leak orifice size were considered. The efficiency of forced ventilation in semi-closed spaces was also investigated. The hydrogen distribution in the ventilation facility was studied through experimental investigation and confirmed by CFD simulation. Our numerical results could be useful in the analysis of safety issues in semi-closed ventilation facilities, such as in mining tunnels. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.