the invention relates to a fuel cell system comprising a housing including a chamber for accommodating a fuel cell stack . the fuel cell system has various features that can also be independently embodied , namely : a u - shaped air channel including air inlet channels and air outlet channels which include an inlet or outlet on the same side of the housing of the fuel cell system ; at least two fans or compressors that are disposed downstream of each other in an air flow direction in the air inlet channel or in the air outlet channel ; a housing that has two additional , separate housing sections apart from a chamber for a fuel cell stack and an air inlet channel and an air outlet channel ; and an air bypass channel which is arranged between an air inlet channel for introducing ambient air into a chamber for the fuel cell stack and an air outlet channel for discharging air from the chamber for the fuel cell stack .