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What IES says its using as curve coefficients for the generic hermetic centrifugal; vsd chiller, it really isn't. It's actually using the same curves as eQuest uses for CentH2OVSD. They are very similar, but with a couple of coefficients different (b & c only). For this particular curve (EIR-f-PL&dT) the coefficients are:

Also, Cnorm is the result of the curve at the design conditions. For curves that do not result in "1" at the design condition, this will "normalize" the curve for you. Though all of the eQuest curves already equal "1" at design conditions and don't need this.

So when I use the eQuest curve coefficients, and with those Cnorm isn't necessary, I get the correct curve, the same as IES is visualizing:

What IES says its using as curve coefficients for the generic hermetic centrifugal; vsd chiller, it really isn't. It's actually using the same curves as eQuest uses for CentH2OVSD. They are very similar, but with a couple of coefficients different (b & c only). For this particular curve (EIR-f-PL&dT) the coefficients are:

Also, Cnorm is the result of the curve at the design conditions. For curves that do not result in "1" at the design rated condition, this will "normalize" the curve for you. Though all of the eQuest curves already equal "1" at design rated conditions and don't need this.this (though if you are using design conditions it might).

So when I use the eQuest curve coefficients, and with those Cnorm isn't necessary, I get the correct curve, the same as IES is visualizing:

What IES says its using as curve coefficients for the generic hermetic centrifugal; vsd chiller, it really isn't. It's actually using the same curves as eQuest uses for CentH2OVSD. They are very similar, but with a couple of coefficients different (b & c only). For this particular curve (EIR-f-PL&dT) the coefficients are:

Also, Cnorm is the result of the curve at the design conditions. For curves that do not result in "1" at the rated condition, this will "normalize" the curve for you. Though all of the eQuest curves already equal "1" at rated conditions and don't need this (though if you are using design conditions it might).

So when I use the eQuest curve coefficients, and with those Cnorm isn't necessary, I get the correct curve, the same as IES is visualizing:

What IES says its using as curve coefficients for the generic hermetic centrifugal; vsd chiller, it really isn't. It's actually using the same curves as eQuest uses for CentH2OVSD. They are very similar, but with a couple of coefficients different (b & c only). For this particular curve (EIR-f-PL&dT) the coefficients are:

Also, Cnorm is the result of the curve at the design conditions. For curves that do not result in "1" at the rated condition, this will "normalize" the curve for you. Though all of the eQuest curves already equal "1" at rated conditions and don't need this (though if you are using design conditions it might).

So when I use the eQuest curve coefficients, and with those Cnorm isn't necessary, I get the correct curve, the same as IES is visualizing:

And this curve is created by using this equation:

[EIRfactor EIRrated = \frac{EIRfPLR}{PLR}]EIRfPLR / PLR

What IES says its using as curve coefficients for the generic hermetic centrifugal; vsd chiller, it really isn't. It's actually using the same curves as eQuest uses for CentH2OVSD. They are very similar, but with a couple of coefficients different (b & c only). For this particular curve (EIR-f-PL&dT) the coefficients are:

Also, Cnorm is the result of the curve at the design conditions. For curves that do not result in "1" at the rated condition, this will "normalize" the curve for you. Though all of the eQuest curves already equal "1" at rated conditions and don't need this (though if you are using design conditions it might).

So when I use the eQuest curve coefficients, and with those Cnorm isn't necessary, I get the correct curve, the same as IES is visualizing:

And this curve is created by using this equation:

EIRrated = EIRfPLR / PLR

UpdateUpdate 2017/12/14 I heard back from IES on this and they found that there is an issue with visualization of chiller curves when using IP units. There is no issue if you are using SI units. It is unclear if this This issue is just with visualization or if it is also with the chiller curves themselves used in themselves, not just the simulation.visualization, so you should use SI units to simulate chillers until the issue is resolved.

What IES says its using as curve coefficients for the generic hermetic centrifugal; vsd chiller, it really isn't. It's actually using the same curves as eQuest uses for CentH2OVSD. They are very similar, but with a couple of coefficients different (b & c only). For this particular curve (EIR-f-PL&dT) the coefficients are:

Also, Cnorm is the result of the curve at the design conditions. For curves that do not result in "1" at the rated condition, this will "normalize" the curve for you. Though all of the default eQuest curves already equal "1" at rated conditions and don't need this (though if you are using design conditions it might).

So when I use the eQuest curve coefficients, and with those Cnorm isn't necessary, I get the correct curve, the same as IES is visualizing:

And this The EIRrated curve is created by using this equation: equation:

EIRrated = EIRfPLR / PLR

Update 2017/12/142018/01/09 I heard back from IES on this and they found that there is an issue with visualization of chiller curves when using IP units. There is no issue if you are using SI units. For default curves in IP there is an incorrect conversion being applied which affects the visualization. This issue is with does not actually affect the simulation results. However, if you create a custom chiller curves themselves, not just curve in IP the visualization, conversion will affect results, so you should use SI units to simulate chillers until the issue is resolved.when inputting a custom chiller curve.

Cnorm is the result of the curve at the design conditions. For curves that do not result in "1" at the rated condition, this will "normalize" the curve for you. Though all of the default eQuest curves already equal "1" at rated conditions and don't need this (though if you are using design conditions it might).

The EIRrated curve is created using this equation:

EIRrated = EIRfPLR / PLR

Update 2018/01/09 I heard back from IES on this and they found that there is an issue with visualization of chiller curves when using IP units. There is no issue if you are using SI units. For default curves in IP there is an incorrect conversion being applied which affects the visualization. This does not actually affect the simulation results. However, if you create a custom chiller curve in IP the conversion will affect results, so use SI when inputting a custom chiller curve.

Cnorm is the result of the curve at the design conditions. For curves that do not result in "1" at the rated condition, this will "normalize" the curve for you. Though all of the default eQuest curves already equal "1" at rated conditions and don't need this (though if you are using design conditions it might).

The EIRrated curve is created using this equation:

EIRrated = EIRfPLR / PLR