An ozone generator unit includes a housing with a first half having a first recess and a second half having a second recess. The ozone generator unit further includes an inlet and an outlet in the housing, a first dielectric disc arranged within the first recess in contact with an inner surface of the first half, a second dielectric disc arranged within the second recess in contact with an inner surface of the second half, and a high voltage electrode, having a gas passage, arranged between the first and second dielectric discs. The high voltage electrode is spaced apart from the first and second dielectric discs using a first spacer and a second spacer to constitute a first gas chamber and a second gas chamber on either side of the high voltage electrode.