Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
The fan model in EnergyPlus is a a sort of whole-system model that includes the fan motor, blade/blower and drive. The fan's motor size is included in the design volume flow rate (and pressure rise) for the fan system. The total fan efficiency is an input which describes the overall fan system and this includes the motor efficiency, blade efficiency, and drive efficiency. In general you can model improved fan motor performance by raising the total fan efficiency. To determine a new value I would suggest as a starting point to form a ratio of the replacement motor's nominal efficiency divided by the original motor's nominal efficiency and multiply this ratio by the original fan system's total fan efficiency.
