Motor-driven fan systems in air handling units (AHUs) account for 15.9% of the electricity consumption in commercial buildings. Currently electronically commutated motors (ECMs) have seen increasing applications to replace induction motors for energy savings. While efficiency models for motor-driven fan systems are essential for building energy management, there is no valid efficiency model for ECM fan systems. Therefore, this paper is to develop and validate an efficiency model for ECM fan systems, which can be applied to evaluate the motor input power at given fan airflow rate and head. First, an efficiency model is developed and calibrated using the manufacturer data of a 5.2 kW ECM fan. Innovatively a fan efficiency correction coefficient is introduced to consider the bias of affinity laws and the correlation between motor efficiency and motor shaft power is verified. Then the calibrated efficiency model is validated in an AHU with an array of four calibrated ECM fans. It was found that the proposed fan efficiency correction coefficient can improve the fan efficiency model accuracy by 20% at 20% rated motor speed. Moreover, the validation results show that the developed efficiency model can accurately evaluate the motor input power with an error of 0.096 kW or 1.8%.

空气处理机组（AHU）中的电动风扇系统占商业建筑用电量的15.9％。当前，电子换向电动机（ECM）越来越多地用于代替感应电动机以节省能源。尽管电机驱动风扇系统的效率模型对于建筑能耗管理至关重要，但ECM风扇系统没有有效的效率模型。因此，本文旨在开发和验证ECM风扇系统的效率模型，该模型可用于评估给定风扇气流速率和扬程下的电动机输入功率。首先，使用5.2 kW ECM风扇的制造商数据开发和校准效率模型。创新地引入了风扇效率校正系数，以考虑亲和力定律的偏差，并验证了电机效率与电机轴功率之间的相关性。然后，在具有四个校准ECM风扇阵列的AHU中验证校准效率模型。结果发现，提出的风扇效率校正系数可以在20％的额定电机转速下将风扇效率模型的精度提高20％。此外，验证结果表明，开发的效率模型可以准确地评估电动机输入功率，误差为0.096 kW或1.8％。结果发现，提出的风扇效率校正系数可以在20％的额定电机转速下将风扇效率模型的精度提高20％。此外，验证结果表明，开发的效率模型可以准确地评估电动机输入功率，误差为0.096 kW或1.8％。结果发现，提出的风扇效率校正系数可以在20％的额定电机转速下将风扇效率模型的精度提高20％。此外，验证结果表明，开发的效率模型可以准确地评估电动机输入功率，误差为0.096 kW或1.8％。