Process of operating an air and fuel supplied fuel cell unit contained in an enclosure and an installation of performing the process

The fuel cell assembly (1) is installed in a room (2) with several air inlets (18a-18d). Several streams (11) of inlet air (FL) converge on the inlet (6), pass through a control valve (5,5a) and pass the cathodes (4a) of the stack of fuel cells (4). Waste gas (AL) is withdrawn from the fuel cell assembly at a pressure lower than that of the incoming air. Hydrogen is supplied to the anodes of the stack of fuel cells.