Abstract: A heating and/or air conditioning installation for the inner space of a motor vehicle, particularly individual cars, comprises programmable and manually adjustable devices for the defrost air (4 and 5), foot air (6 and 7) and aeration air (8, 9, 10) inlets. These devices enable one to consider the various sensitivities of the driver and the passengers to temperature and to air streams, since they control different air inlets by means of separate automatic and programmable temperature selectors (11 and 12) for each lateral half (17 and 18) of the inside of the car and by means of adjusting devices (23-26), also independent and previously adjusted according to the needs.