9
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).
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 3, 4 and 5 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) / (1.08 x CFM)
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
3
5
6
8
10
15
19
20
21 or 25
AV PTC24B14
550
650
700
800
850
NR
NR
NR
NR
AV PTC30B14
600
700
750
875
950
NR
NR
NR
NR
AV PTC36C14
NR
850
900
1000
1200
1440
1500
1500
NR
AV PTC48C14
NR
850
900
1000
1200
1440
1500
1500
NR
AV PTC42D14
†
850**
1250
1300
1500
1550
1720
NR
1800
NR
AV PTC48D14
††
NR
1250
1300
1500
1550
1720
NR
1815
1850
AV PTC60D14
†††
NR
1250
1300
1500
1550
1780
NR
1850
1850
MINIMUM CFM REQUIRED FOR HEATER KITS
Heater Kit (Kw)
Please ref er to page 16 f or specif ic heater kit application guidelines.
Table 6
3
5
6
8
10
15
19/20
25
800
11
18
22
30
35
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
11
15
18
27
35
44
1800
5
8
10
13
16
24
31
39
2000
4
7
9
12
14
21
28
35
CFM
HEAT KIT NOMINAL kW
220/1/60 SUPPLY VOLTAGE - TEMP. RISE °F
Table 4
3
5
6
8
10
15
19/20
25
800
12
19
23
31
37
1000
9
15
19
25
30
44
1200
8
12
15
21
25
37
49
62
1400
7
11
13
18
21
32
42
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 3
3
5
6
8
10
15
19/20
25
800
10
17
21
28
33
1000
8
13
17
22
27
40
1200
7
11
14
19
22
33
45
56
1400
6
10
12
16
19
29
38
48
1600
5
8
10
14
17
25
33
42
1800
5
7
9
12
15
22
30
37
2000
4
7
8
11
13
20
27
33
CFM
HEAT KIT NOMINAL kW
208/1/60 SUPPLY VOLTAGE - TEMP. RISE °F
Table 5
