An air conditioning apparatus having at least a first heat exchanger for exchanging heat with air circulating there through; a cooling circuit for a cooling fluid, having a path that passes through the first heat exchanger; a compressor including an electric motor, for circulating the cooling fluid in the cooling circuit; an electrical power unit configured to absorb an input electrical current or power and to generate a variable infeed voltage, for powering the electric motor with an infeed electrical current, a controller connected to the electrical power unit, adapted to receive input data representative of a reference value for the input electrical current or power, and programmed to set the electrical power unit to generate the infeed voltage at a reference amplitude and/or frequency, so that the input electrical current or power is below the reference value.