A previous post helped clarify the origin of fan performance curves.
I'm also curious about the source and derivation of pump performance curves.
The image below is from the ANSI/ASHRAE/IES Standard 90.1-2022 Performance Rating Method Reference Manual.
- Constant-speed pump riding the pump curve: (0, 3.2485, -4.7443, 2.5294)
- Variable-speed pump without differential-pressure reset: (0, 0.5726, -0.3010, 0.7347)
- Variable-speed pump with differential-pressure reset: (0, 0.0205, 0.4101, 0.5753)
These coefficients are published in Table 5.21 of Achieving the 30% Goal: Energy and Cost Savings Analysis of ASHRAE Standard 90.1-2010 (Thornton et al., 2011), which only states that PNNL developed the three curves. I have not been able to trace the underlying data or derivation any further.
Does anyone know how these coefficients were originally derived?
