Abstract: A system for managing the flow of fluids within a closed-loop system includes a pump controller and a variable-speed pump in communication with a conduit circuit including at least one one pressure-independent control valve (PICV). By using PICVs instead of conventional, two-way, two-way, pressure-dependent valves, the pump controller can monitor system needs and adjust the the speed of the variable-speed pump to more efficiently deliver pressure to the system without overshooting flow requirements, leading to less energy consumed and less cost incurred. A method method of variable-speed pumping including the use of PICVs is also disclosed.