Condensers have a slow-turning, screened or perforated metal-covered drum on which the ginned lint forms a batt. The batt is discharged between doffing rollers to the lint slide. 

Conveying air supplied by a high-volume centrifugal fan passes through the screen on the drum and is usually discharged out one end of the drum through an air duct. The discharged air then goes to dust abatement equipment and then into the atmosphere.

The speed of the condenser drum is adjusted to the capacity of the gin so that the smooth, solid batt is formed.