For standard, ducted A/C systems without zoning the diagnostically tested system airflow and fan-efficacy shall meet the following criteria:

• Airflow =350 cfm/ton, and
• Fan-Efficacy =0.58 w/cfm.

Alternatively, standard duct systems without zoning may use an alternative method of demonstrating compliance based on sizing of the return duct system per Tables 150.0-B/C. Return Duct Sizing