scope:

This paper describes the development and testing of the characteristic curve fan model-a gray-box model. This model produces fan ejìciency as a function of airflow and fan static pressure. It is accurate, relatively easy to calibrate, and could be easily incorporated into commercial simulation programs. Also presented is an application of an existing model to predict fan speed from airflow and fan static pressure. These models were developed as apart of a larger research project to develop design guidelines for built-up variable air volume fan systems. The models have been successfully employed in comparative analysis of fan types, wheel diameters, fan staging, and analysis of supply pressure reset.