Direct air capture (DAC) has emerged as a promising technology for mitigating carbon emissions. Given the very low concentration of carbon dioxide in ambient air, efficient capture methods are essential. Interestingly, carbon dioxide concentration tends to increase in occupied buildings, making them ideal environments for DAC. Higher carbon dioxide concentrations facilitate easier capture, and adsorption-based technologies have proven to be energy-efficient for this purpose. In this paper, the potential of carbon capture through adsorption in hospital air handling units is assessed. The carbon dioxide concentration within the building is firstly evaluated considering the occupancy levels. Furthermore, the amount of carbon dioxide that can be effectively captured is quantified by considering the adsorption properties of commercially available materials. The methodology is then applied to a multi-purpose building of the Hospital of Parma in the north of Italy. The findings of the paper demonstrate the convenience of implementing DAC in hospital settings, where carbon dioxide concentrations are high due to human activity. By leveraging energy-efficient adsorption technologies, hospitals can play a crucial role in reducing carbon emissions and contributing to a sustainable future.