S-203A Two Piece Air Handler External Static - Daikin DAR09 Service Instructions Manual

SERVICING
TOTAL EXTERNAL STATIC

S-203A TWO PIECE AIR HANDLER EXTERNAL STATIC

To determine proper airflow, proceed as follows:
1. Using a Inclined Manometer or Magnehelic gauge, measure
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.
Supply Static
+ .20" wc
Return Static
- .30" wc
TOTAL EXTERNAL STATIC
S-204 COIL STATIC PRESSURE DROP
1. Using a draft gauge (inclined manometer), connect the posi-
tive probe underneath the coil and the negative probe above
the coil.
2. A direct reading can be taken of the static pressure drop
across the coil.
3. Consult proper table for quantity of air.
STATIC PRESSURE DROP
If the total external static pressure and/or static pressure drop
exceeds the maximum or minimum allowable statics, check for
closed dampers, dirty filters, undersized or poorly laid out duct
work.
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