9
NOTE:
Units operating in high static pressure applications may
require a deeper field constructed “P” style trap than is shown
in Figure 12 to allow proper drainage and prevent condensate
overflow.
NOTE:
Trapped lines are required by many local codes. In
the absence of any prevailing local codes, please refer to the
requirements listed in the Uniform Mechanical Building Code.
A drain trap in a
draw-through
application prevents air from
being drawn back through the drain line during fan operation
thus preventing condensate from draining, and if connected
to a sewer line to prevent sewer gases from being drawn into
the airstream during blower operation.
Use of a condensate removal pump is permitted when nec-
essary. This condensate pump should have provisions for
shutting off the control voltage should a blocked drain occur.
See Auxiliary Alarm Switch section for more details. A trap
must be installed between the unit and the condensate pump.
IMPORTANT NOTE:
The evaporator coil is fabricated with
oils that may dissolve styrofoam and certain types of plastics.
Therefore, a removal pump or float switch must not contain
any of these materials.
9 DUCTWORK
Do not operate this product without all the ductwork attached.
CAUTION
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 application. 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 OBJEC-
TIONABLE FUMES/ODORS INTO THE DUCTWORK.
The return ductwork is to be connected to the air handler
bottom (upflow configuration).
10 RETURN AIR FILTERS
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 dimension 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 specification 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.
NOTE:
TRANSFORMER SUB-ASSEMBLY
Before installing the Heat Kit, uninstall the transformer sub-as-
sembly (Figure 13). Make sure to unplug 12-Pin connector
before uninstalling the uninstalling the transformer sub-as-
sembly. Follow the Heat Kit Installation Manual to install the
Heat Kit. Install transformer sub-assembly back to the unit
(Figure 13). Plug in 12-Pin connectors and secure screws
while installing transformer sub-assembly back to the unit
after heater kit installation.
The heating mode temperature rise is dependent upon the
system airflow, the supply voltage, and the heat kit size (kW)
selected. Use data provided in Tables 4, 5 and 6 to determine
the temperature rise (°F).
NOTE:
For emergency heat, set the dipswitch on PCB. For
heating mode, use the thermostast user menu.
For installations not indicated above the following formula is
to be used:
TR = (kW x 3412) x (Voltage Correction) / (1.08 x CFM)
Where: TR = Temperature Rise
kW = Heater Kit Actual kW
3412 = Btu per kW
VC* = 1.0 (240 Supply Volts)
= .92 (230 Supply Volts)
= .84 (220 Supply Volts)
= .77 (210 Supply Volts)
= .75 (208 Supply Volts)
1.08 = Constant
CFM = Measured Airflow
*VC (Voltage Correction)
NOTE:
The Temperature Rise Tables can also be used to
estimate the air handler airflow delivery. When using these
tables for this purpose set the room thermostat to maximum
heat and allow the system to reach steady state conditions.
Insert two thermometers, one in the return air and one in the
supply air. The temperature rise is the supply air temperature
minus the return air temperature. Using the temperature
rise calculated, CFM can be estimated from the TR formula
above. See Specification Sheet and/or Service Manual for
more information.
H
eat
K
it
S
election
For heat kit selection, see the Specification Sheet for each
specific Air Handler.
