below the following cfm/ton levels to reduce the risk of evaporator coil freeze-up. • 130 cfm/ton - 1 compressor • 160 cfm/ton - 2 compressors • 190 cfm/ton - 3 compressors • 220 cfm/ton - All compressors I • Utilizes a Variable Frequency Drive (VFD) to stage the supply blower airflow • VFD alters the frequency and voltage of the power