Abstract: Air conditioning (AC) system for motor vehicles comprising two fans connected in a series circuit whereby the first fan provides only a part of the air required for admission into the passenger compartment, and the remaining contribution to the desired quantity of air is provided by the second fan. Under normal operating conditions, where all openings such as windows, doors and sunroof (if any) are closed, both fans are independently regulated by a main controller device in such a manner that the air on the passenger compartment experiences a slight overpressure in order to permit the rapid entry and exit of air flow through the passenger compartment and a uniform air circulation therein. A manometer is included in the AC system to provide air pressure differential data (between the passenger compartment and the outside) to the main controller.