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# EnergyPlus HVACCurveFitTool for chiller EIRfPLR curve?

EnergyPlus' Chiller:Electric:EIR requires a quadratic performance curve for it's Electric Input to Cooling Output Ratio Function of Part Load Ratio (EIRfPLR) curve.

Is it possible to create this quadratic curve using EnergyPlus' HVAC Curve Fit Tool?

I can create the biquadratic curves for CAPfT and EIRfT using the tool, but I'm not quite sure how to create the quadratic EIRfPLR curve.

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Does the Chiller:Electric:EIR accept a biquadratic? If not, then the EIRfPLR curve will just represent EIR as a function of part load ratio regardless of lift (dT)?

( 2016-10-14 12:42:13 -0600 )edit

Hey @pflaumingo , you're correct, I have edited my question accordingly. I was having flashbacks to my previous eQUEST/DOE-2 days where the chiller EIRfPLR curve would accept a 'biquadratic in ratio & dT' curve to model EIR as a function of both PLR and lift (dT).... old habits die hard, haha.

( 2016-10-14 15:09:59 -0600 )edit

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From the INPUTS sheet...

DX Coil Type = Other
Independent Variable = Flow or Temperature (either will work)


For the independent variable, either option will work as long as the corresponding column in the performance data is PLR.

The performance data header names are less important than getting the dependent and independent variable data in the correct columns.

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Hello,

I am trying to generate EIRfPLR quadratic curve using EnergyPlus' HVAC Curve Fit Tool. The output sheet gives two set of coefficients CAPFTemp and EIRFTemp even though I imputed PLR (Independent variable), Cap and Power (Dependent variable) in the column whereas I expected only one, EIRfPLR. Any insight?

thanks,

( 2019-11-18 11:26:28 -0600 )edit

@Javed see the last sentence of my answer. The spreadsheet names the curve objects based on the independent variable selection, so either flow or temp. As long as your data is in the correct column the object names don't matter, just change them before exporting to IDF.

( 2019-11-18 12:03:57 -0600 )edit

thank you. It helps!

( 2019-11-18 12:27:12 -0600 )edit