A fuel cell electric power generation system using air as both a coolant and an oxidant comprises an electric power generation subsystem, an air filter subsystem, a power and control electronics unit (PEU) subsystem comprising a DC/DC converter, and an air fan subsystem. The subsystems are arranged such that air circulation through the system is improved and the risk of moisture damage to sensitive PEU components is reduced. In one embodiment, the air filter subsystem is positioned ahead of the PEU subsystem, which is positioned ahead of the power generation subsystem, which is positioned ahead of the air fan subsystem in the direction of air flow, such that air is drawn by the air fan subsystem through the air filter subsystem, over the PEU subsystem, and through the electric power generation subsystem providing filtered air to cool the PEU prior to entering the fuel cell stack to provide oxygen for the electrochemical reaction.