Abstract: A system for ventilation, dehumidification, and cooling according to an exemplary embodiment in the present disclosure may include an outdoor unit dehumidifying and cooling introduced outside air; and an indoor unit connected to the outdoor unit to perform ventilation, in which the outdoor unit includes a dehumidification rotor, an evaporative cooler, an evaporative condenser, a ventilation damper, a heating unit, and a control module operating and stopping at least one of the dehumidification rotor, the evaporative cooler, the evaporative condenser, the ventilation damper, or the heating unit.