9
9
DUCTWORK
CAUTION
If secondary drain is not installed, the secondary
access must be plugged.
This air handler is designed for a complete supply and return
ductwork system.
To ensure correct system performance, the ductwork is to be sized
to accommodate 350-450 CFM per ton of cooling with the static
pressure not to exceed 0.5" in w.c. Refer to ACCA Manual D,
Manual S and Manual RS for information on duct sizing and appli-
cation. Flame retardant ductwork is to be used and sealed to the
unit in a manner that will prevent leakage.
NOTE:
A downflow application with electric heat must have an L-
shaped sheet metal supply duct without any outlets or registers
located directly below the heater.
9.1 Return Ductwork
DO NOT LOCATE THE RETURN DUCTWORK IN AN AREA THAT
CAN INTRODUCE TOXIC, OR OBJECTIONABLE FUMES/ODORS
INTO THE DUCTWORK. The return ductwork is to be con-
nected to the air handler bottom (upflow configuration).
10
RETURN AIR FILTERS
Do not operate this product without all the ductwork
attached.
Each installation must include a return air filter. This filtering may
be performed at the air handler using the factory filter rails or
externally such as a return air filter grille. When using the factory
filter rails, a nominal 16x20x1”, 20x20x1” or 24x20x1” (actual di-
mension must be less than 23-½”x20”) filter can be installed on a
B, C and D cabinet respectively (the cabinet size is the seventh
letter of the model number). Washable versions are available
through your local Daikin distributor.
11
ELECTRIC HEAT
Refer to the installation manual provided with the electric heat kit
for the correct installation procedure. All electric heat must be
field installed. If installing this option, the ONLY heat kits that are
permitted to be used are the Daikin produced HKS series. Refer to
the air handler unit’s Serial and Rating plate or the HKS specifica-
tion sheets to determine the heat kits compatible with a given air
handler. No other accessory heat kit besides the HKS series may
be installed in these air handlers.
Air Handler
3" MIN.
POSITIVE LIQUID
SEAL REQUIRED
AT TRAP
Drain
Connection
2" MIN.
Figure 12
NOTE: TRANSFORMER SUB-ASSEMBLY
Before installing the Heat Kit, uninstall the transformer sub-assem-
bly (Figure 21). Make sure to unplug 12-Pin connector before
uninstalling the uninstalling the transformer sub-assembly. Follow
the Heat Kit Installation Manual to install the Heat Kit. Install trans-
former sub-assembly back to the unit (Figure 21). Plug in 12-Pin
connectors and secure screws while installing transformer sub-as-
sembly back to the unit after heater kit installation.
Un
ins
tal
l
Ins
tal
l
Transformer
Sub-Assembly
Figure 21
