Air conditioning device for conditioning the air present in an inner environment of a means of transport, said device comprising: - a fluidic circuit configured to circulate a first operative fluid; - conditioning means cooperating, in use, with the circuit to condition the first operative fluid and, through this, the air present in the inner environment of the means of transport; and - a radiator mass configured to receive a second operative fluid and defining a heat exchange interface between the second operative fluid received and the air that laps/crosses, in use, the radiator mass ; wherein the air conditioning device is of modular type and the conditioning means and the radiator mass are housed in respective, separate casings connectable in a releasable manner to one another directly or with interposition of parts; wherein the air conditioning device comprises: - a first casing housing the conditioning means , defining a first module (M1) of the device , having a first inlet opening for the air to be conditioned and a first outlet opening for the conditioned air; and - a second casing housing the radiator mass , defining a second module (M2) of the device , having a second inlet opening for the air and a second outlet opening for the air; characterized in that the first casing includes a first connection interface arranged at the first outlet opening , in that the second casing includes a second connection interface arranged at the second inlet opening , and in that said first connection interface is couplable to said second connection interface by means of releasable fastening means , directly or with interposition of parts. - a fluidic circuit configured to circulate a first operative fluid; - conditioning means cooperating, in use, with the circuit to condition the first operative fluid and, through this, the air present in the inner environment of the means of transport; and - a radiator mass configured to receive a second operative fluid and defining a heat exchange interface between the second operative fluid received and the air that laps/crosses, in use, the radiator mass ; wherein the air conditioning device is of modular type and the conditioning means and the radiator mass are housed in respective, separate casings connectable in a releasable manner to one another directly or with interposition of parts; wherein the air conditioning device comprises: - a first casing housing the conditioning means , defining a first module (M1) of the device , having a first inlet opening for the air to be conditioned and a first outlet opening for the conditioned air; and - a second casing housing the radiator mass , defining a second module (M2) of the device , having a second inlet opening for the air and a second outlet opening for the air; - a first casing housing the conditioning means , defining a first module (M1) of the device , having a first inlet opening for the air to be conditioned and a first outlet opening for the conditioned air; and - a second casing housing the radiator mass , defining a second module (M2) of the device , having a second inlet opening for the air and a second outlet opening for the air; characterized in that the first casing includes a first connection interface arranged at the first outlet opening , in that the second casing includes a second connection interface arranged at the second inlet opening , and in that said first connection interface is couplable to said second connection interface by means of releasable fastening means , directly or with interposition of parts. <EOS>