Abstract: The invention concerns a device (100) for treatment of indoor air. The device (100) comprises a supply air chamber (11) and from this nozzles (12a1, 12a2 . . . ) or a nozzle gap (12) to make a flow of fresh supply air flow out of the supply air chamber, which flow (J1) will induce a circulated airflow to flow out of the room (H) through a heat exchanger (10). The circulated airflow (J2) joins the supply airflow (J1), whereby the combined airflow (J1+J2) is made to flow out of the device. In the device (100) its heat exchanger (10a1, 10a2; 10) is used to either cool or heat the circulated airflow (J2). The device (100) for treatment of indoor air may also be a so-called passive beam, which can be fitted close to the ceiling of the room space (H), whereby the heated air is cooled by the heat exchanger (10) of the passive beam (100) as it ascends in the room space approaching the heat exchanger (10), from which upon being cooled it will descend back into the occupied zone of the room space (H).