The invention relates to a displacement ventilation system configured for conditioning the climate in a space with a greenhouse like climate characteristic. The system comprises an air supply opening configured for supplying air directly to an occupied zone of the space an air displacement device for generating an airflow to the air supply opening and a suction opening configured for extracting air from said space above the occupied zone. The displacement ventilation system further comprises one or more PCM units including a phase change material (PCM) having a melting temperature corresponding to a desired space temperature, wherein the displacement ventilation system is configured for generating an airflow from the suction opening along surfaces of the PCM-unit to the air supply opening.
