Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
You should use the performance curve coefficients for condenser water entering temperature if you are modeling a water-cooled condenser.
From the Input-Output Reference for the AirConditioner:VariableRefrigerantFlow object:
From the Engineering Reference for the same object:
That information leads me to believe that EnergyPlus has the capability to model water-cooled condensers for VRF systems. I agree with you that the documentation for the Cooling Capacity Ratio Modifier Function of Low Temperature Curve Name input field you referenced is not clear and makes it seem like it will only use outdoor air dry-bulb. However, after digging around in the source code, I am confident in telling you that the VRF condenser inlet will use the water node you assign and not outdoor air dry-bulb IF you have specified WaterCooled in the Condenser Type input field.
