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RE: [EnergyPlus_Support] Re: Is there any way to simplify DX Unit Model?




I have not actually done this myself.

When you are only interested in building heat load, what you are observing is the heat gain or loss, and what ever part is replaced by air-conditioning.

Temperture, PLR and mass flow rate are the three major parameters that the system would provide, when delivering the heat or cool.

If the system is for cooling, the condenser will need to reject the same amount heat to the condenser loop and at the tower.

At each stage more power is used, and some of these is added into the heat flow path.



If you multiply the heat amount at the evaporator by 1/COP provided by the manufacturer, you get the electrical power. which include the compressor motor power and the fan motor power.

When the load is not unitorm, the COP may change, typically from 2 to 6 and some even claim to be 9 max.  After an EPlus simulation, there will be a spread sheet with temperature,  plr, mass flowrate, etc, and the heating or cooling from the coil.

Performance curves are acturally using coefficients and a mathmatical formula using the PLR, Temperature and flowrate to calculate the COP for that condition.  Therefore, now you can generate a column with different COP values for different DX heat transfer rate.