The COVID-19 pandemic was an extremely urgent threat to human life, and similar outbreaks may occur in the future. Due to people spending more than 90% of their time indoors, enclosed indoor environments are among the most high-risk spaces for airborne transmission. Airborne transmission comes from the inhalation of aerosol droplets which are exhaled by an infected person. Recent studies in office environments show the personal ventilation was effective in reducing the infection risk compared with conventional ventilation. A fully mixed ventilation system requires around a two times higher airflow rate for the same infection risk as the personal system. Despite the promising evidence personal ventilation have not gained wide usage in practical installations. One rea-son might be that the proposed personal ventilation systems require tight integration into to furnishing, while ventilation installations are commonly located in the ceiling. A new ceiling integrated protective ventilation concept has been developed to over-come above mentioned installation challenge. In previous research it has been applied with promising results in patient environments. In current research the protective flow concept is applied for office environment. The performance is verified against fully mixed conditions and to various person-al ventilation concepts, which were studied in earlier research with the same lay-out and operating parameters. Protective flow concept outperforms with a clear margin a fully mixed ventilation that is most commonly used in office environments. The exposure index for protective flow concept is even at the comparable level with the earlier studied localized personal ventilation systems.