Field Controls FAPV180-AC Manual page 13

9. Adjust the speed control knob on the FAPV until this static pressure is measured. NOTE: the static
pressure more closely matching the actual desired fl owrate may be "interpolated" from adjacent
column cfm values if desired. Contact Field Controls Technical Support for assistance if needed for
help with interpolation.
10. Example: 50 cfm of ventilation fl ow rate while the FAPV operates is desired to meet ventilation
requirements. A model IAD-6 6" intake hood with 27 feet of fl ex duct is installed, with one 90° bend:
• "Equivalent length" is 27 + 12 = 39 feet
• The row for 6" hood and duct, 50 feet should be used
• The column for Flex Duct having the closest value to 50 cfm has the value of 47 cfm (closer
to 50 than 40 or 57).
• The static pressure at the top of this column is 0.035. Adjust the speed knob until slightly
over this value is achieved, since 50 is greater than 47.
page 13 of 20 P/N 780104900 Rev A 09/20