As temperatures rise around the world and people work more hours throughout the day, the necessity for a comfortable work environment and better thermal comfort has increased. Ventilation systems might have an impact on workers’ health in relation to providing suitable levels of indoor air quality and thermal comfort. Thereby, the purpose of this research was to test different existing installations in an office by taking measures and carrying out a questionnaire to the office staff, so the performance of the systems and the thermal comfort provided could be evaluated. The investigated systems were: wall confluent jets supply device, windows façade supply device and active chilled beams.

The results show that the mean room temperature from both confluent jets ventilation (CJV) and façade-integrated displacement ventilation (FIDV) is higher than with the mixing ventilation with active chilled beams. Also the maximum temperature difference between neck level and ankle level was lower with the active chilled beams (ACB) system. Nevertheless, the draught rate was higher for the chilled beams. In addition to the fact that the mixing ventilation (MV) systems have the drawback of mixing contaminated air with the fresh air supplied, which can lead to lower performance and diseases for the occupants.

For the office studied, results confirm that the CJV provides better overall ventilation performance than the mixing and displacement supply devices used in this study, as it combines the positive effects of both mixing and stratification principles.