Exergy of boson and fermion fluxes

Particles with zero and non-zero rest mass are considered in both the classical and ultra-relativistic limits. Relationships that may be used for both fermions and bosons are derived. The exergy flux of free particles involves an efficiency-like factor affecting the energy flux. This factor contains the ambient temperature and the effective particle flux temperature and it is generally different from both the usual Carnot factor and the Petela factor appearing in the exergy of blackbody radiation fluxes, respectively. Some particular cases considered here show that free Fermi particles carry less available work than Bose particles and that the classical approximation yields higher values of the efficiency-like factors than the ultra-relativistic assumption.