Natural ventilation is an interesting topic of research. It could contribute in supplying adequate airflow rates, achieving thermal comfort in patients’ wards in hospitals and reduce energy consumption. Although, it’s still challenging due to the high fluctuations in ambient airflow and changeable weather conditions which should be studied carefully to be able to achieve stable and comfortable thermal conditions in patients’ wards. This study investigates the feasibility of integrating natural ventilation with existing HVAC system, when it’s possible to have natural ventilation as an efficient alternative and to which extent could we use natural ventilation in summer. This will be explored using Ecotect weather tool thermal simulation model and computational fluid dynamics using DesignBuilder. Picardy Wallonia Medical Center was chosen as a case study since it was precisely designed to benefit from natural ventilation and all windows in patients’ wards could be opened to benefit from ambient air. Moreover, it contains two typical prototypes of patients’ wards: single-bed ward which presents the present orientation in patient ward design, and a creative multiple-bed prototype which was designed to achieve better functional design solutions and more comfortable thermal conditions. The expected results of metrological analysis will evaluate ambient weather suitability for natural ventilation and how some uncomfortable conditions could be solved using passive techniques. Based on metrological analysis single patient ward will be subjected to CFD simulation to investigate their actual ventilation performance when windows are open when natural ventilation is a potential. This study will be useful for designers and HVAC engineers to give them a perspective regarding natural ventilation as a potential in ward design. Also it will be useful for standards organizations to have a deeper look regarding natural ventilation margins in patients’ wards in hospitals.