System for cooling and/or heating aircraft devices (12, 14, 16, 18) to be cooled and/or heated, which comprises: - a first individual cooling and/or heating system (20, 22), which is associated with a first aircraft device (12, 14) to be cooled and/or heated, - a second individual cooling and/or heating system (24, 26), which is associated with a second aircraft device (16, 18) to be cooled and/or heated, - a cooling and/or heating energy supply apparatus which is adapted to supply cooling and/or heating energy generated by the first and/or the second individual cooling and/or heating system (20, 22, 24, 26) to the first and/or the second aircraft device (12, 14, 16, 18) to be cooled and/or heated, and - a control device which is adapted to receive and process signals characteristic of the cooling and/or heating requirements of the first and/or the second aircraft device (12, 14, 16, 18) to be cooled and/or heated and of the load condition of the first and/or the second individual cooling and/or heating system (20, 22, 24, 26), and which is further adapted to control, on the basis of said signals and taking account of load-dependent energy requirement data of the first and second individual cooling and/or heating system (20, 22, 24, 26), the operation of the first and/or the second individual cooling and/or heating system (20, 22, 24, 26) and/or the supply of cooling and/or heating energy generated by the first and/or the second individual cooling and/or heating system (20, 22, 24, 26) to the first and/or the second aircraft device (12, 14, 16, 18) to be cooled and/or heated, in such a way that the total energy requirement of the first and second individual cooling and/or heating system (20, 22, 24, 26) necessary for generation of the cooling and/or heating energy by the first and/or second individual cooling and/or heating system (20, 22, 24, 26) is minimised. - a first individual cooling and/or heating system (20, 22), which is associated with a first aircraft device (12, 14) to be cooled and/or heated, - a second individual cooling and/or heating system (24, 26), which is associated with a second aircraft device (16, 18) to be cooled and/or heated, - a cooling and/or heating energy supply apparatus which is adapted to supply cooling and/or heating energy generated by the first and/or the second individual cooling and/or heating system (20, 22, 24, 26) to the first and/or the second aircraft device (12, 14, 16, 18) to be cooled and/or heated, and - a control device which is adapted to receive and process signals characteristic of the cooling and/or heating requirements of the first and/or the second aircraft device (12, 14, 16, 18) to be cooled and/or heated and of the load condition of the first and/or the second individual cooling and/or heating system (20, 22, 24, 26), and which is further adapted to control, on the basis of said signals and taking account of load-dependent energy requirement data of the first and second individual cooling and/or heating system (20, 22, 24, 26), the operation of the first and/or the second individual cooling and/or heating system (20, 22, 24, 26) and/or the supply of cooling and/or heating energy generated by the first and/or the second individual cooling and/or heating system (20, 22, 24, 26) to the first and/or the second aircraft device (12, 14, 16, 18) to be cooled and/or heated, in such a way that the total energy requirement of the first and second individual cooling and/or heating system (20, 22, 24, 26) necessary for generation of the cooling and/or heating energy by the first and/or second individual cooling and/or heating system (20, 22, 24, 26) is minimised.