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

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SERVICING
TOTAL EXTERNAL STATIC
S-203A TWO PIECE AIR HANDLER EXTERNAL STATIC
To determine proper airow, proceed as follows:
1. Using a Inclined Manometer or Magnehelic gauge, measure
the stac pressure between the outlet of the evaporator
coil and the inlet of the air handler, this will be a negave
pressure ( for example -.30”wc)
2. Measure the stac pressure of the supply duct at the outlet
of the unit, this should be a posive pressure (for example
.20”wc).
3. Add the two readings together (for example -.30”wc +
.20”wc = .50”wc total stac pressure.
NOTE: Both readings may be taken simultaneously and read
directly on the manometer if so desired.
4. Consult proper air handler airow chart for quanty of air
(CFM) at the measured external stac pressure.
Supply Static
+ .20” wc
Return Static
- .30” wc
TOTAL EXTERNAL STATIC
S-204 COIL STATIC PRESSURE DROP
1. Using a dra gauge (inclined manometer), connect the posi-
ve probe underneath the coil and the negave probe above
the coil.
2. A direct reading can be taken of the stac pressure drop
across the coil.
3. Consult proper table for quanty of air.
STATIC PRESSURE DROP
If the total external stac pressure and/or stac pressure drop
exceeds the maximum or minimum allowable stacs, check for
closed dampers, dirty lters, undersized or poorly laid out duct
work.