Having the right surroundings and physical conditions in a workplace is crucial for ones ability to accomplish a job efficiently and staying physically and mentally healthy at the same time. A often overlooked part of public workplaces is the air quality and overall function of the ventilationsystem, which can make a substantial difference for the well-being of staff. In this study, the ventilationsystem of Rodengymnasiet, a high school in Norrtälje municipality has been examined and evaluated since staff at the school have some complains regarding the air quality at their workplace. The study was conducted through preliminary reviews of blueprints for the building and discussion with the staff about specifics for their complaints, where most complaints were related to uncomfortable temperatures in offices. Then measurements of humidity, air temperature and CO₂-levels were taken in several offices and classrooms during regular workdays with normal attendance. This, in combination with visual inspection of the ventilationsystem and reviewing of the latest results of inspection gave the results that no obvious faults in the ventilation seem to exist, and thusly the complaints and feelings of uncomfortableness seem to not stem from flawed ventilation. A simplified estimation of the ventilationsystem energy usage was also made from the information available and inspected state of the components in the system. The most important conclusion made from these results is that Rodengymnasiet seem to have a very well functioning ventilationsystem, and the suggestions made in this study only serve to add a small degree of optimization to a already well constructed and well maintained system.