Air is moved through a network of insulated ducts to air outlets to each room in the building. These outlets, or registers, are large to allow the air to be freely discharged into each area. Because of the high air flow needed for evaporative cooling it is not possible to cool individual rooms. The cooler air then travels through the rooms to open doors or windows, where it is exhausted. A central panel installed inside your home provides control over the system.
Some units also have timers and comfort controls.
Automatic adjustment of cooling and fan speeds provides the preselected comfort level. These units are installed through an aperture in an external wall. Operation is identical to the ducted units but the capacity is generally much smaller. As the air flow delivered is lower, the fan, filter pad and outside of the unit is smaller. This system only has basic controls and is suited to single open plan areas.