Method for operating a building air-conditioning system (100; 100') with a plurality of heat exchangers (13.1, 13.2; 13.1.1,..., 13.3.31) in a dynamically hydraulically compensated state, in which, in the building air-conditioning system (100; 100'): - at least one heat exchanger and/or one heat generator and at least one circulating pump are arranged in a base circuit with advance and return lines (1, 2), - at least two circuit strands (10.1', 10.2', 10.3') are connected to the advance and return lines (1, 2) in parallel at branch points (16, 17; 16.1, 16.2, 17.1, 17.2), - each circuit strand (10.1', 10.2', 10.3') comprises at least one loop (11.1, 11.2) having at least one heat exchanger (13.1, 13.2; 13.1.1,..., 13.3.1), an auxiliary advance and return line (18.1,..., 18.3, 19.1,..., 19.3), and at least one remotely actuable control valve (15.1, 15.2; 15.1.1,..., 15.3.1), which is connected to a control unit via a wired or wireless datalink (14.1, 14.2); characterised in that, during operation of the building air-conditioning system: - a differential pressure Δp between the advance line and the return line and an actual volume flow rate V̇ in the advance line is measured; - the valve setpoint values (Y 1,..., Y 13) of the control valves (15.1, 15.2; 15.1.1,..., 15.3.1) are calculated and adjusted individually and continuously in such a way that a volume sub-flow suitable for providing the required heat is initiated in the loop, - the substitute resistors K VSi of the control valves (15.1, 15.2; 15.1.1,..., 15.1.3) and the pressure loss coefficients ζ i are each defined as a variable and calculated for: ∘ the base circuit with advance and return lines (1, 2), ∘ each loop (11.1, 11.2), and ∘ each further portion in the advance and return lines (1, 2) and in the auxiliary advance and return lines (18.1,..., 18.3, 19.1,..., 19.3) between branch points (16, 17; 16.1, 16.2, 17.1, 17.2), associated portions in the (auxiliary) advance and return lines (18.1,..., 18.3, 12.1,..., 12.3) in which the same volume flow rate prevails being assigned the same pressure loss coefficient ζ i; in that by way of the substitute resistors K VSi and the pressure loss coefficients ζ i the volume sub-flows are calculated by linear regression by the NELDER-MEAD iterative method and stored in the control unit, - a number n of matrices M i with n columns being formed using the variables ζ i, K VSi, where n is the number of all unknown pressure loss coefficients ζ i and hydraulic substitute resistors K VSi; - the measured actual volume flow rate V̇ and the measured differential pressure Δp being used for error calculation. - at least one heat exchanger and/or one heat generator and at least one circulating pump are arranged in a base circuit with advance and return lines (1, 2), - at least two circuit strands (10.1', 10.2', 10.3') are connected to the advance and return lines (1, 2) in parallel at branch points (16, 17; 16.1, 16.2, 17.1, 17.2), - each circuit strand (10.1', 10.2', 10.3') comprises at least one loop (11.1, 11.2) having at least one heat exchanger (13.1, 13.2; 13.1.1,..., 13.3.1), an auxiliary advance and return line (18.1,..., 18.3, 19.1,..., 19.3), and at least one remotely actuable control valve (15.1, 15.2; 15.1.1,..., 15.3.1), which is connected to a control unit via a wired or wireless datalink (14.1, 14.2); characterised in that, during operation of the building air-conditioning system: - a differential pressure Δp between the advance line and the return line and an actual volume flow rate V̇ in the advance line is measured; - the valve setpoint values (Y 1,..., Y 13) of the control valves (15.1, 15.2; 15.1.1,..., 15.3.1) are calculated and adjusted individually and continuously in such a way that a volume sub-flow suitable for providing the required heat is initiated in the loop, - the substitute resistors K VSi of the control valves (15.1, 15.2; 15.1.1,..., 15.1.3) and the pressure loss coefficients ζ i are each defined as a variable and calculated for: ∘ the base circuit with advance and return lines (1, 2), ∘ each loop (11.1, 11.2), and ∘ each further portion in the advance and return lines (1, 2) and in the auxiliary advance and return lines (18.1,..., 18.3, 19.1,..., 19.3) between branch points (16, 17; 16.1, 16.2, 17.1, 17.2), associated portions in the (auxiliary) advance and return lines (18.1,..., 18.3, 12.1,..., 12.3) in which the same volume flow rate prevails being assigned the same pressure loss coefficient ζ i; ∘ the base circuit with advance and return lines (1, 2), ∘ each loop (11.1, 11.2), and ∘ each further portion in the advance and return lines (1, 2) and in the auxiliary advance and return lines (18.1,..., 18.3, 19.1,..., 19.3) between branch points (16, 17; 16.1, 16.2, 17.1, 17.2), associated portions in the (auxiliary) advance and return lines (18.1,..., 18.3, 12.1,..., 12.3) in which the same volume flow rate prevails being assigned the same pressure loss coefficient ζ i; - a number n of matrices M i with n columns being formed using the variables ζ i, K VSi, where n is the number of all unknown pressure loss coefficients ζ i and hydraulic substitute resistors K VSi; - the measured actual volume flow rate V̇ and the measured differential pressure Δp being used for error calculation.