With the aim of reducing the climate change potential, this study assesses the potential climate impact of two commonly used ventilation systems for office buildings, using the life cycle assessment method. The choice of a ventilation system for office buildings influences the potential climate change impact during the construction of the building (A-stage), use (B-stage) and demolition (C-stage). Therefore, this study includes all life cycle stages including (A-stage) use (B2, B4, B6) and demolition (C-stage) for two different ventilation systems. The ventilation system should both fulfill the ventilation air flow requirements and be able to cool down the office workplace, two systems that can accomplish these requirements have been chosen to assess as a case study. The first system is a variable air volume (VAV) system where both flow and cooling are controlled by temperature setpoints. The second system is a constant air volume (CAV) system with active chilled beams. The study evaluates different operational scenarios, showing that the CAV system with chilled beams has a higher operational climate change impact than the VAV system when both operate all the time, while with ventilation off during unoccupied time the results show the opposite. Results also show a lower embodied climate change impact in CAV system with chilled beams due to less material usage in its production. These findings suggest that the selection of a ventilation system should consider both operational and embodied impacts to optimize climate performance across the building’s life cycle.