Contents - Index



SPECHEAT [J/kg-K, J/kmol-K, kJ/kg-K, kJ/kmol-K, Btu/lbm-R, Btu/lbmol-R] returns the constant pressure specific heat of the specified substance.  The value and units of the returned value depends on the Unit System setting.  For pure substances that obey the ideal gas law and incompressible substances, the specific heat function has temperature as its only other argument in addition to the substance name.  For pure real fluids, two independent arguments are required.  Note that, at saturation, pressure and temperature are not independent.  If the specific heat of saturated liquid or vapor is required, it is necessary to provide the quality or some other quality-dependent property.  The specific heat of a two-phase mixture with a quality other than 0 or 1 is infinite and a value cannot be returned for this state.  


For AirH2O, three arguments are required for the SPECHEAT function.  One of these arguments must be total pressure (P).  The remaining two can be any of the following: temperature (T), enthalpy (H), relative humidity (R), humidity ratio (W), wetbulb (B), or dewpoint (D).   X (for quality) is not allowed.  Note also that the specific heat returned for substance AirH2O (psychrometrics) is per unit mass of dry air.


Note that the SpecHeat function is identical to the CP function. 


The list of property identifiers needed in the calling arguments and instructions are available in the Thermophysical Function help.