The contact factor of a coil is defined as the efficiency for dehumidification.
A 100% efficient coil will
bring the moisture content of air to the saturation moisture content at the
apparatus dew-point, gc. The
contact factor of the coil can be defined by moisture content differences:
or by specific enthalpy differences:
The contact factor of a coil depends on the design of heat transfer surfaces, air velocity and drainage of condensate.