The intelligent-air-SYSTEM makes it possible to heat or cool the respective building as desired, thus replacing the conventional heating system and its radiator. The heat or cold produced by the is-SYSTEM passes through the ventilation of the ia-SYSTEM into the desired room, which is then air-conditioned or heated. The spent air is then removed from the room and passed through the refrigeration or heat recovery and then discharged to the environment. No technical room or other equipment is needed. Only the minimum amount of ventilation ducts is installed, which can all be placed invisibly behind the walls. This results in a high material and installation cost savings. The ia-SYSTEM can be cooled or heated efficiently while massively reducing CO2 emissions.