S-203A Two Piece Indoor Unit External; Static - Daikin DX17VSS B Series Service Instructions Manual

SERVICING

S-203A TWO PIECE INDOOR UNIT EXTERNAL

STATIC

two piece indoor unit refers to CAPE(A)/CHPE cased coil
with Gas furnace/Modular Blower.
to determine proper air movement, proceed as follows:
1. With clean filters in the indoor unit, use a draft gauge
(inclined Manometer or Magnehelic gauge) to measure
the static pressure of the return duct at the inlet of the
Gas furnace or Modular Blower, this will be a negative
pressure (for example, -0.30"wc).
2. Measure the static pressure of the supply duct at the
outlet of the Gas furnace or Modular Blower, this
should be a positive pressure (for example, 0.20"wc).
3. Add the two (2) readings together for total abso-
lute value of external static pressure (for example,
-0.30"wc + 0.20"wc = 0.50"wc total static pressure).
NOTE: Both readings may be taken simultaneously and
read directly on the manometer if so desired.
if an Electronic Air Cleaner is used in conjunction with the
indoor unit, the readings must also include these compo-
nents.
4. Consult proper Gas furnace or Modular Blower airflow
chart for quantity of air (CfM) at the measured external
static pressure.
if the total external static pressure exceeds the minimum
or maximum allowable statics, check for closed dampers,
registers, undersized and/or oversized poorly laid out duct
work.
Supply Duct
Cased Coil
(CAPE(A)/CHPE)
Supply Static
Inclined
Manometer or
Magnehelic
gauge
Return Static
Return Duct
Case of Cased Coil + Gas Furnace
Supply Static
Blower
(inside)
Inclined
Manometer or
Magnehelic gauge
Return Static
Case of Cased Coil + Modular Blower
Blower
Gas Furnace
(inside)
Air
flow
Supply Duct
Modular Blower
Cased Coil
(CAPE(A)/CHPE)
Air
flow
Return Duct
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