Measuring Fan Performance
Generally speaking, Air Movement and Control Association Standard 230 establishes uniform test procedures for determining the performance of ceiling fans.
AMCA 230 establishes uniform methods for laboratory testing of circulating fans to determine performance in terms of thrust for rating, certification or warranty purposes. The 1999 version described a method to determine the developed thrust and used a simple equation to convert the measured thrust to airflow. During the periodic review process, it was determined that the calculated airflow was too high; therefore, this version no longer artificially calculates airflow, but leaves the measured performance in units of thrust.
The current version, AMCA 230-12, re-introduces airflow with a revised equation and new efficiency metrics. The official scope of the standard was limited to ceiling fans under 6 ft (1.8 m) in diameter, so the current standard does not apply to HVLS fans. A new version of the standard is currently under consideration.