A compact air conditioning system is fitted into the center of a vehicle and has a common drive shaft (10e) which powers two centrifugal blowers on each side of the middle line. Each pair of blowers supplies a pair of air ducts, i.e. one upper duct (23) for mainly fresh air and one lower duct (22) for mainly recirculated air. The blowers are fitted across the front of the system, behind control flaps which regulate the mix of fresh and recirculated air. The two air ducts pass through an air conditioning module (24) followed by a selected flow over a heat exchanger (25). The upper duct supplies the fresh air demisting jets while the lower duct supplies the foot level vents.
