Field Controls FCMC Manual page 9

SETTING THE VENTILATION TIME
If the ventilation time is already known, rotate the knob to the appropriate number.
If the ventilation time is NOT known:
1) Lookup or calculate the continuous ventilation rate Qtot (2013 to current):
2) Lookup* or measure the Intermittent ventilation fl ow rate (FAV rate)
If this is unknown, the fl ow rate can be measured with appropriate tools and should be done with the central
fan operating. This can be initiated using the quick start method detailed later in the manual FAV rate can
also be approximated using look-up tables if the duct length, diameter, and number of bends are known.
3) Calculate the ventilation Time:
Set the knob to the appropriate number of minutes per the calculation above.
KEY
Qtot: Continuous Ventilation Rate
Nbr: Number of Bedrooms
FAV Rate: Intermittent Ventilation Rate (CFM)
*Lookup is in reference to architectual drawings that include an HVAC schedule, table, or defi ned FAV fl ow
rates for each apartment size and their associated (AHU) Air Handler Unit equipment.
Qtot=0.03 (fl oor sq.ft.) + 7.5 (Nbr +1)
Time = (Qtot X 60) / (FAV rate)
Qtot
Time =
FAV Rate
TIME
CONTROL
KNOB
X 60
=
780110400 | RevA | 07/23