9
Do not operate this product without all the ductwork
attached.
A drain trap in a
draw-through
application prevents air from being drawn back through the drain line during fan opera-
tion 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.
Field experience has shown condensate drain traps with an open vertical Tee between the air handler and the condensate
drain trap can improve condensate drainage in some applications, but may cause excessive air discharge out of the open
Tee. The manufacturer does not prohibit this type of drain but we also do not recommend it due to the resulting air
leakage. Regardless of the condensate drain design used, it is the installer’s responsibility to ensure the condensate drain
system is of sufficient design to ensure proper condensate removal from the coil drain pan.
Use of a condensate removal pump is permitted when necessary. This condensate pump should have provisions for
shutting off the control voltage should a blocked drain occur. A trap must be installed between the unit and the conden-
sate 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.
Tip
: Priming the “P” trap may avoid improper draining at the initial installation and at the beginning of the cooling
season.
9 Ductwork
This air handler is designed for a complete supply and re-
turn 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 OBJECTIONABLE FUMES/
ODORS INTO THE DUCTWORK. The return ductwork is to be connected to the air handler bottom (upflow configu-
ration).
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).
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 HKS series.
Refer to the air handler unit’s Serial and Rating plate or the HKS specification sheets to determine the heat kits compat-
ible with a given air handler. No other accessory heat kit besides the HKS series may be installed in these air handlers.
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 2, 3 and 4 to determine the temperature rise (°F).
NOTE:
For installations not indicated above the following formula is to be used:
TR = (kW x 3412) x (Voltage Correction) / (1.08XCFM)
Where:
TR
= Temperature Rise
kW
= Heater Kit Actual kW
3412 = Btu per kW
VC*
= .96 (230 Supply Volts)
= .92 (220 Supply Volts)
= .87 (208 Supply Volts)
1.08
= Constant
CFM = Measured Airflow
*VC (Voltage Correction)