Multi-story building (61A, 61C, 61D, 61E, 111, 121), comprising: a) a plurality of outside units of a split type, unitary air conditioning system; b) a first passageway (S, CS, 22, 52, 92, 102) constructed internally within said building and being configured with- i. mounts for said plurality of outside units; and ii. a plurality of sets of penetrations (13, 14), each of said sets of penetrations dedicated to accommodate the extension therethrough of, and sized similarly as, a corresponding fluid circuit conduit through which refrigerant circulates between an inside unit and one of said outside units; c) a second passageway (E, 24, 56, 96) constructed internally within said building and in fluid communication with said first passageway to receive air discharged from each of said outside units, said second passageway terminating at an opening of said building through which said discharged air is exhausted to the atmosphere; and d) each of said outside units, which comprises a compressor, a condenser and a fan, wherein one or both of said first and second passageways upwardly extends across at least two stories of said building, wherein said first and second passageways have walls that are essentially closed, with the exception of the wall that adjoins said first and second passageways and that is formed with an opening through which said discharged air is flowable, characterized in that each of said plurality of outside units is a ducted condenser unit (15, 16) which has a casing (23, 35) within which said compressor, condenser and fan are mounted, said casing being mounted by one or more of said mounts, wherein said first passageway comprises an upwardly extending suction shaft (S, CS, 22, 52, 92) in fluid communication with at least one air inlet, through which ambient air is introducible and flowable upwardly into each of said DCUs, and terminates at a roof of the building, and said second passageway comprises an upwardly extending exhaust shaft (E, 24, 56, 96), wherein the fan of each of said ducted condenser units is a centrifugal fan which is operable to direct the air flow within said first passageway towards said condenser at an external static pressure ranging from 80 to 100 Pascal, to overcome pressure losses of the air circulating in said first and second passageways and to achieve a desired level of heat dissipation. a) a plurality of outside units of a split type, unitary air conditioning system; b) a first passageway (S, CS, 22, 52, 92, 102) constructed internally within said building and being configured with- i. mounts for said plurality of outside units; and ii. a plurality of sets of penetrations (13, 14), each of said sets of penetrations dedicated to accommodate the extension therethrough of, and sized similarly as, a corresponding fluid circuit conduit through which refrigerant circulates between an inside unit and one of said outside units; i. mounts for said plurality of outside units; and ii. a plurality of sets of penetrations (13, 14), each of said sets of penetrations dedicated to accommodate the extension therethrough of, and sized similarly as, a corresponding fluid circuit conduit through which refrigerant circulates between an inside unit and one of said outside units; c) a second passageway (E, 24, 56, 96) constructed internally within said building and in fluid communication with said first passageway to receive air discharged from each of said outside units, said second passageway terminating at an opening of said building through which said discharged air is exhausted to the atmosphere; and d) each of said outside units, which comprises a compressor, a condenser and a fan, wherein one or both of said first and second passageways upwardly extends across at least two stories of said building, wherein said first and second passageways have walls that are essentially closed, with the exception of the wall that adjoins said first and second passageways and that is formed with an opening through which said discharged air is flowable, wherein one or both of said first and second passageways upwardly extends across at least two stories of said building, wherein said first and second passageways have walls that are essentially closed, with the exception of the wall that adjoins said first and second passageways and that is formed with an opening through which said discharged air is flowable, wherein said first passageway comprises an upwardly extending suction shaft (S, CS, 22, 52, 92) in fluid communication with at least one air inlet, through which ambient air is introducible and flowable upwardly into each of said DCUs, and terminates at a roof of the building, and said second passageway comprises an upwardly extending exhaust shaft (E, 24, 56, 96), wherein the fan of each of said ducted condenser units is a centrifugal fan which is operable to direct the air flow within said first passageway towards said condenser at an external static pressure ranging from 80 to 100 Pascal, to overcome pressure losses of the air circulating in said first and second passageways and to achieve a desired level of heat dissipation.