ECM pump recommendation

Torsten

Finishing an Uponor-designed radiant heat system. Boiler is a Navien NCB-180E. Primary loop will use Navien's built-in pump. Secondary loop will have a single pump and I was wondering if someone could recommend a proper ECM pump for this application?

Following are more details and calculations from the Uponor design:

• Secondary loop separated by a 20 gallon buffer tank (HTP SSU-20B)
• Total RH Circuits: 16
• Total Manifolds: 3
• Total Zones: 7
• Smallest zone Head Loss: 0.9
• Total system Head Loss: 7.0
• Total Flow: 5.31
• Water Temp: 92.2
• Total Heating Load: 25,374 Btu/hr (Radiant Back Losses: 5,049 Btu/hr; Radiant Heating: 19,964 Btu/hr)
• First floor has in-slab tubing; second floor has heat transfer plates mounted to the sub-floor from below

NY_Rob

The Grundfos ALpha2 may be a prefect fit for your needs, look at the pump curve chart...

https://www.supplyhouse.com/Grundfos-99163903-ALPHA2-15-55-F-Cast-Iron-Circulator-Pump-w-Terminal-Box