KND is an atmospheric tower, the air flow through this tower is produced by the density differential that exists between the heated (less dense) air inside the stack and the relatively cool (more dense) ambient air outside the tower.

Although this towers are more expensive than other normal tower types, they are used extensively in the field of electric power generation, where large unified heat loads exist, and where long amortization periods allow sufficient time for the absence of fan power to recoup the differential cost of the tower.