Contact Factor of nozzles

The contact factor of nozzles is defined as the efficiency for humidification. A 100% efficient nozzle system will bring the moisture content of air to the saturation moisture content at the apparatus dew-point, gc. The contact factor of the nozzle system can be defined by moisture content differences:

or by specific enthalpy differences:

The contact factor of a nozzle system depends on the design of nozzles, nozzle arrangement and water pressure.