Abstract: For controlling the opening of a valve (10) in an HVAC system (100) to regulate the flow ? of a fluid through a thermal energy exchanger (2) of the HVAC system (100) and adjust the amount of energy E exchanged by the thermal energy exchanger (2), determined are the flow ? through a valve (10) and the temperature difference ?T=Tin?Tout between the supply temperature Tin of the fluid entering the thermal energy exchanger (2) and the return temperature Tout of the fluid exiting the thermal energy exchanger (2). The opening of the valve (10) is controlled depending on the flow ? and the temperature difference ?T. For example, the opening of the valve (10) is controlled depending on a control criterion c=ƒ(?,?T), calculated from the flow ? and the temperature difference ?T.

Abstract: A hydraulic network (1) having plural parallel zones (Z1, Z2) with a regulating valve (V1, V2) in each zone for regulating a flow of fluid (?1, ?2) through respective zones. Characteristic parameters of the hydraulic network (1) include static flow capacity values (Kex,a, Kex,b) of the zones. Measurement data sets are recorded which include a determined value of a hydraulic system variable of the hydraulic network (1), e.g. the total flow (?tot) or the system pressure (?P), and valve positions of the regulating valves (V1, V2) set for the determined value of the hydraulic system variable. The characteristic parameters are calculated from plural measurement data sets, by grouping related measurement data sets, which include the same value of the hydraulic system variable but different valve positions, and by using the flow capacity (Kvalve,a, Kvalve,b) of the regulating valves (V1, V2) at the valve positions included in the data sets.

Abstract: A hydraulic network (1) having plural parallel zones (Z1, Z2) with a regulating valve (V1, V2) in each zone for regulating a flow of fluid (?1, ?2) through respective zones. Characteristic parameters of the hydraulic network (1) include static flow capacity values (Kex,a, Kex,b) of the zones. Measurement data sets are recorded which include a determined value of a hydraulic system variable of the hydraulic network (1), e.g. the total flow (?tot) or the system pressure (?P), and valve positions of the regulating valves (V1, V2) set for the determined value of the hydraulic system variable. The characteristic parameters are calculated from plural measurement data sets, by grouping related measurement data sets, which include the same value of the hydraulic system variable but different valve positions, and by using the flow capacity (Kvalve,a, Kvalve,b) of the regulating valves (V1, V2) at the valve positions included in the data sets.

Abstract: For controlling the opening of a valve (10) in an HVAC system (100) to regulate the flow ? of a fluid through a thermal energy exchanger (2) of the HVAC system (100) and adjust the amount of energy E exchanged by the thermal energy exchanger (2), determined are the flow ? through a valve (10) and the temperature difference ?T=Tin?Tout between the supply temperature Tin of the fluid entering the thermal energy exchanger (2) and the return temperature Tout of the fluid exiting the thermal energy exchanger (2). The opening of the valve (10) is controlled depending on the flow ? and the temperature difference ?T. For example, the opening of the valve (10) is controlled depending on a control criterion c=f(?,?T), calculated from the flow ? and the temperature difference ?T.