Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
According to the Engineering Reference Manual (p.1044), the electric consumption of the fan is calculated as:
Rated electric power (W) = Maximum Fan Flow Rate (m3/s) * Fan Delta Pressure (Pa) / Fan Total Efficiency
This matches your results: 0.9*710/0.45 = 1420 W
In order to get the electric power you want, I would adjust the either the fan total efficiency or the delta pressure. According to the equations of the simple fan model in the manual, it seems those values aren't used anywhere else in the fan model.
