Process and apparatus for heating a passenger compartment of a vehicle equiped with a fuel cell

The method of heating a fuel cell powered motor vehicle passenger compartment uses the coolant fluid fed via a radiator (6) to be used for heating. The heating circuit uses an air heater (9) and the fuel cell (1) has reformer (15) which produces heated gas. The method involves selectively preheating the heated gas for transfer to the coolant. Claims include a heater using the method.