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Your EIRfPLR curve looks correct. However, this curve is not properly implemented in code. The EIRfPLR should output a constant 1 (or something far less impactful if you have other data.

HP_EIRFPLR output [1, 1, 1, 1, 1]

The power is calculated as:

this->powerUsage =
    (this->loadSideHeatTransfer / this->referenceCOP) * eirModifierFuncPLR * eirModifierFuncTemp * InputPowerMultiplier * this->cyclingRatio;

where:

loadSideHeatTransfer = availableCapacity * operatingPLR; InputPowerMultiplier is a defrost term which is 1 when not in defrost cyclingRatio is the fraction of time the unit cycles below min PLR

So in this equation, the loadSideHeatTransfer already includes the impact of PLR and again applying another PLR factor using the eirModifierFuncPLR curve is double dipping and causing the high COPs. If you were to try to use this EIRfPLR curve with this equation it would be more like:

HP_EIRFPLR output [1.03, 1.02, 1.01, 1, 1] to account for inefficiencies at low PLR (I am guessing on my curve outputs).

Your EIRfPLR curve looks correct. However, this curve is not properly implemented in code. The EIRfPLR should output a constant 1 (or something far less impactful if you have other data.

HP_EIRFPLR output [1, 1, 1, 1, 1]

The power is calculated as:

this->powerUsage =
    (this->loadSideHeatTransfer / this->referenceCOP) * eirModifierFuncPLR * eirModifierFuncTemp * InputPowerMultiplier * this->cyclingRatio;

where:

loadSideHeatTransfer = availableCapacity * operatingPLR; operatingPLR;

InputPowerMultiplier is a defrost term which is 1 when not in defrost defrost

cyclingRatio is the fraction of time the unit cycles below min PLR

So in this equation, the loadSideHeatTransfer already includes the impact of PLR and again applying another PLR factor using the eirModifierFuncPLR curve is double dipping and causing the high COPs. If you were to try to use this EIRfPLR curve with this equation it would be more like:

HP_EIRFPLR output [1.03, 1.02, 1.01, 1, 1] to account for inefficiencies at low PLR (I am guessing on my curve outputs).

Your EIRfPLR curve looks correct. However, this curve is not properly implemented in code. The EIRfPLR should output a constant 1 (or something far less impactful if you have other data.

HP_EIRFPLR output [1, 1, 1, 1, 1]

The power is calculated as:

this->powerUsage =
    (this->loadSideHeatTransfer / this->referenceCOP) * eirModifierFuncPLR * eirModifierFuncTemp * InputPowerMultiplier * this->cyclingRatio;

where:

loadSideHeatTransfer = availableCapacity * operatingPLR;

InputPowerMultiplier is a defrost term which is 1 when not in defrost

cyclingRatio is the fraction of time the unit cycles below min PLR

So in this equation, the loadSideHeatTransfer already includes the impact of PLR and again applying another PLR factor using the eirModifierFuncPLR curve is double dipping and causing the high COPs. If you were to try to use this EIRfPLR curve with this equation it would be more like:

HP_EIRFPLR output [1.03, 1.02, 1.01, 1, 1] to account for inefficiencies at low PLR (I am guessing on my curve outputs).

Your EIRfPLR curve looks correct. However, this curve is not properly implemented in code. The EIRfPLR should output a constant 1 (or something far less impactful if you have other data.data).

HP_EIRFPLR output [1, 1, 1, 1, 1]

The power is calculated as:

this->powerUsage =
    (this->loadSideHeatTransfer / this->referenceCOP) * eirModifierFuncPLR * eirModifierFuncTemp * InputPowerMultiplier * this->cyclingRatio;

where:

loadSideHeatTransfer = availableCapacity * operatingPLR;

InputPowerMultiplier is a defrost term which is 1 when not in defrost

cyclingRatio is the fraction of time the unit cycles below min PLR

So in this equation, the loadSideHeatTransfer already includes the impact of PLR and again applying another PLR factor using the eirModifierFuncPLR curve is double dipping and causing the high COPs. If you were to try to use this EIRfPLR curve with this equation it would be more like:

HP_EIRFPLR output [1.03, 1.02, 1.01, 1, 1] to account for inefficiencies at low PLR (I am guessing on my curve outputs).

See https://github.com/NREL/EnergyPlus/issues/10387