Charli K. Matthews interviews Ashley Scott Zachry from Grundfos to learn more about distributed pumping at AHR 2023.
Distributed Pumping is a paradigm shift in hydronic system design that optimizes the entire HVAC system while improving occupant comfort. It replaces energy-wasting balance and control valves in HVAC systems with intelligent, reliable and maintenance-free pumps that generate pressure only when and where it’s needed. The result is over 50% pump energy savings and a constantly re-balanced HVAC system.
Distributed pumping is a hybrid-pumping arrangement, combining variable primary and variable-secondary systems which reduces pump energy between 50% and 80%, significantly improves delta-T and provides a constantly auto-balanced HVAC system that improves occupant comfort.
Distributed simply means that the secondary pumps are distributed through the piping network to be located adjacent to each zone, specifically the air handling unit or bank of fan-coil units. These distributed pumps will be installed in place of control valves and balancing valves. A low resistance check valve is added to the discharge side of each distributed pump which will prevent backflow in the HVAC system.
The primary pumps are only sized for the pressure losses through the bypass in the mechanical room and along with full system flow. This will drastically reduce the size of the pumps, costs, horsepower and physical space, compared to primary/secondary pumping arrangements.