The Climate Act approved by the Danish government and the subsequent initiation of CO2 emission limits for buildings in the Danish Building Regulations by 2023 set the target for research in this area. The currently published studies lack in focus on the HVAC systems, especially in relation to the embodied carbon. This study aims to assess the embodied carbon of ventilation systems in educational and office buildings. The currently available environmental data on the ventilation systems is insufficient to conduct a reliable assessment, therefore a detailed assessment based on component specific quantities and material composition was carried out. The generalised results from the assessment of three case-buildings set new GWP reference values for the ventilation system and its components, applicable for buildings falling under the investigated building category. The findings of the study also highlight the critical components of the system in terms of their embodied carbon, followed by investigation into the carbon reduction potential of these. The results of this investigation lead to suggestions of necessary actions to be taken within the industry to reduce the environmental impact of ventilation systems and components.