An air-conditioning method and system for an automotive vehicle for controlling passenger compartment air temperature under comfortable air control conditions, that is, under comfortable outlet duct air volume and temperature according to the perception of individual passengers, once the control conditions are adjusted by the passenger. The air-conditioning system according to the present invention comprises, in addition to a microcomputer, a temperature sensor, a temperature preset device, and the like, a blower-fan motor speed selector manually operated by the passenger, a non-volatile memory unit for storing the manually-adjusted blower-fan motor speeds classified on the basis of difference between detected air temperature and preset air temperature, vehicle travelling conditions, and the time elapsed since the system was turned on. In the first five minutes of operation the system can memorize a desired sequence of blower speeds selected by the occupant as well as the temperature difference between the compartment and outdoors and the vehicle speed. This information is stored in nonvolatile memory so that when the system is subsequently restarted, and the same environmental conditions exist, the desired blower speeds are implemented. The system also has an automatic mode in which blower speeds are selected from a pre-programmed table.