Abstract: The invention relates to a method for conditioning air by means of a ventilation system, in which in order to set a specified target air state characterized by air humidity and air temperature, air having an initial air state is cooled and optionally dehumidified with the aid of an air cooler (10), by a coolant supply apparatus assigned to the air cooler (10) for a coolant supplied to the air cooler (10) regulating both a coolant mass flux and a coolant inlet temperature in accordance with the initial air state and the specified target air state. Moreover, the invention relates to an apparatus for air conditioning is provided.