# Chiller performance curve adjustment for ASHRAE90.1 Baseline case

This question is related to my previous post, but I separated.

I want to model ASHRAE90.1 Baseline cases. Specific COP and IPLV need to be input. COP is easy to be input. For IPLV, `Chiller:Electric:EIR`

has three performance curves that directly affect the IPLV calculation.

`Electric Input to Cooling Output Ratio Function of Part Load Ratio Curve`

`Cooling Capacity Function of Temperature Curve`

`Electric Input to Cooling Output Ratio Function of Temperature Curve`

Each curve has many Coefficients. **Which Coefficient should be adjusted to get the target IPLV?**

ANSI/ASHRAE/IES Standard 90.1-2016 Performance Rating Method Reference Manual shows two curves: *Chiller Cooling Capacity Adjustment Curve* and *Electric Chiller Cooling Efficiency Adjustment Curves*. And the Manual says that the default curves should be used for the Baseline case. Actually, the coefficients of the two curves shown in the Manual are different from the defalut coefficients which are generated from `HVACTemplate:Plant:Chiller`

. It may be because EnergyPlus uses SI unit and the Manual is written with IP unit. I'm not sure. But if these two curves should not be changed, **the only curve we can change for the Baseline case is Electric Input to Cooling Output Ratio Function of Part Load Ratio Curve**. This curve is

`Curve:Quadratic`

and it has only three coefficients. I think any of the three coefficients can be changed. Is my interpretation correct?