Instructions / Assembly

11
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.
Do not operate this product without all the ductwork
attached.
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 bot-
tom (upflow configuration).
10 Return Air Filters
Each installation must include a return air filter. This fil-
tering may be performed at the air handler using the fac-
tory 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
compatible 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 4, 5, AND 6 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)
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 room air temperature. Using the
temperature rise calculated, CFM can be estimated from
the TR formula above. See Service Manual for more
information.
3568101519/2025
800 1219233137
1000 9 1519253044
1200 8 121521253749 62
1400 7 111318213242 53
1600 6 9 12 15 19 28 37 46
1800 5 8 10 14 16 25 33 41
2000 5 7 9 12 15 22 30 37
CFM
HEAT KIT NOMINAL kW
230/1/60 SUPPLY VOLTAGE - TEMP. RISE °F
Table 4
3568101519/2025
800 1118223035
1000 9 14 18 24 28 42
1200 7 12 15 20 24 35 47 59
1400 6 10 13 17 20 30 40 51
1600 6 9 111518273544
1800 5 8 101316243139
2000 4 7 9 12 14 21 28 35
CFM
HEAT KIT NOMINAL kW
220/1/60 SUPPLY VOLTAGE - TEMP. RISE °F
Table 5