Why is E+ auto-sizing, oversizing the DX cooling coil?
I'm designing a DX split system for a small data center in energy plus. The calculated Design Load is 11,805 W and the program gives a coil final gross total capacity of 26,554 W. It seems like E+ is defaulting to a 610^-5 m3/sW flow rate overcapacity. When I manually input different supply airflow rates into the parent Unitary system, the capacity goes down to around 13,000 W. How do I get E+ to get a more realistic value from the auto-size function so I can iterate this simulation in JePlus?
Any input would be much appreciated!
Have you found an answer?
I have noted this as well. I suspect that EnergyPlus is not sizing the coil based on design day conditions. Rather, it seems to be sizing the coil based on ideal air loads. For example, if the design day conditions close the outside air damper (ie. zero outside air), it seems that the coil sizing still accounts for the minimum outside air (ie. total is the zone load plus the minimum outside air load (aka Design Outdoor Air Flow Rate).