Tandem print modules with interstitial bar for optimizing airflow

A printing unit comprising:

• a unit chassis having a pair of side bars interconnected by a pair of end bars;
• a first print module mounted on the unit chassis, the first print module comprising a respective first printhead having an associated first print zone;
• a second print module mounted on the unit chassis downstream of the first print module relative to a media feed direction, the second print module comprising a respective second printhead having an associated second print zone;
• an aerosol extractor positioned downstream of the second printhead, the aerosol extractor having one or more suction nozzles configured for providing an airflow through at least one of the first and second print zones;
• and
• an interstitial bar positioned in a space between the first and second printheads, the interstitial bar extending between the side bars parallel with the first and second printheads,
• wherein the interstitial bar is configured to modulate the airflow through at least one of the first and second print zones.