SERVICING
86
Air Handler Static Pressure Readings
S-203 SINGLE PIECE AIR HANDLER EXTERNAL
STATIC PRESSURE
To determine proper airflow, proceed as follows:
1. Using a Inclined Manometer or Magnehelic gauge ,
measure the static pressure of the return duct at the inlet of
the air handler, this will be a negative pressure ( for example
-.30"wc)
2. Measure the static pressure of the supply duct at the outlet
of the air handler, this should be a positive pressure (for
example .20"wc).
3. Add the two readings together (for example -.30"wc +
.20"wc = .50"wc total external static pressure.
NOTE:
Both readings may be taken simultaneously and read
directly on the manometer if so desired.
4. Consult proper air handler airflow chart for quantity of air
(CFM) at the measured external static pressure.
Supply Static
+.20”wc
Return Static
-.30”wc
S-203A TWO PIECE AIR HANDLER EXTERNAL
STATIC PRESSURE
To determine proper airflow, proceed as follows:
1. Using a Inclined Manometer or Magnehelic gauge, mea-
sure the static pressure between the outlet of the evaporator
coil and the inlet of the air handler, this will be a negative
pressure ( for example -.30"wc)
2. Measure the static pressure of the supply duct at the outlet
of the unit, this should be a positive pressure (for example
.20"wc).
3. Add the two readings together (for example -.30"wc +
.20"wc = .50"wc total static pressure.
NOTE:
Both readings may be taken simultaneously and read
directly on the manometer if so desired.
4. Consult proper air handler airflow chart for quantity of air
(CFM) at the measured external static pressure.
