NPM Pumps Curves

Performance Curves – Variable Speed

 The NP Multi is available with variable speed pumping or constant speed pumps. The premium (most efficient) option includes variable speed central pumping for three to five heat pumps with a zone valve for each heat pump.

The central pump is controlled based upon differential pressure. As the zone valves open and close based upon the operation of the heat pump (on/off or modulating), the system pressure changes, causing the pump to adjust speed to attain the water flow needed for the number of heat pumps running.

Variable speed pumping is available with two models and three combinations. The Magna3 40-120 and 40-180 may be configured as a single insulated pump, two insulated pumps in parallel, or two insulated pumps in series. The curves below provide both performance and power consumption for the various combinations.



Performance Curves – Constant Speed

The NP Multi constant speed flow center includes one, two or three pumps for each heat pump. Each heat pump controls the pump(s) for that particular circuit. Due to the flow characteristics of series/parallel pump combinations, Geo-Flo suggests using the NP Multi online Calculator on the Geo-Flo Design Calculators website. If the pressure drop has already been calculated, a Series/ Parallel Pump Calculator is available in the Pump Sizing section of the Design Calculators website.