1053681-UIM-B-0514
Johnson Controls Unitary Products
3
SECTION III: UNIT INSTALLATION
UNIT SIZING
1. The size of the unit should be based on an acceptable heat loss or
gain calculation for the structure. ACCA, Manual J or other
approved methods may be used.
2. Only connect the air handler to a duct system which has an external
static pressure within the allowable range.
3. Airflow must be within the minimum and maximum limits approved
for electric heat and evaporator coils.
4. When an air handler is installed so that supply ducts carry air circu-
lated by the air handler to areas outside the space containing the air
handler, the return air shall also be handled by duct(s) sealed to the
air handler casing and terminating in the space to be cooled/
heated.
5. Refer to the unit rating plate for the air handler model number, and
then see the dimensions page of this instruction for supply air ple-
num dimensions. The plenum must be installed according to the
instructions.
6. The installer must check available supply power and verify that it is
within the normal operating voltage range for the unit. The accept-
able voltage range for these units is as follows:
CLEARANCES
Clearances must be taken into consideration, and provided for as fol-
lows:
1. Refrigerant piping and connections - minimum 12” recommended.
2. Maintenance and servicing access - minimum 36” from front of unit
recommended for blower motor / coil replacement.
3. Condensate drain lines routed to clear filter and panel access.
4. Filter removal - minimum 36” recommended.
5. The ductwork and plenum connected to this unit are designed for
zero clearance to combustible materials.
6. A combustible floor base accessory is available for downflow appli-
cations of this unit, if required by local code.
FIGURE 2:
Dimensions & Duct Connection Dimensions
J
D
Blower
Compartment
Service
Disconnect
Panel
Drain Pan Connections
for Horizontal Applications
Refrigerant
Connections
Drain Connections
for Upflow
Applications
7-11/32”
B
A
K
C
1-1/2”
Top Outlet
Dimensions
Filter
Access
20-5/16”
E
Bottom Inlet
Dimensions
13”
F
A024-001
TABLE 1:
Dimensions
1
Models
Dimensions
Wiring Knockouts
2
Refrigerant
Connections
Line Size
A
B
C
D
E
F
J
K
Height
Width
Depth
Power
Control
Liquid
Vapor
AHR18B3XH21
46”
17-1/2”
21-1/2”
16-1/2”
13-29/32” 16-1/2”
7/8” (1/2”)
1-3/8”(1")
1-23/32” (1-1/4”)
7/8” (1/2”)
3/8”
3/4”
AHR22B3XH21
46”
17-1/2”
16-1/2”
13-29/32” 16-1/2”
AHR24B3XH21
46”
17-1/2”
16-1/2”
13-29/32” 16-1/2”
AHR30B3XH21
46”
17-1/2”
16-1/2”
13-29/32” 16-1/2”
AHR36B3XH21
46”
17-1/2”
16-1/2”
13-29/32” 16-1/2”
AHR29C3XH21
52”
21”
21-1/2”
17-13/32”
20”
AHR34C3XH21
52”
21”
21-1/2”
17-13/32”
20”
AHR42C3XH21
52”
21”
21-1/2”
17-13/32”
20”
AHR48D3XH21
57”
24-1/2”
26”
20-29/32” 23-1/2”
7/8”
AHR60D3XH21
57”
24-1/2”
26”
20-29/32” 23-1/2”
1. All dimensions are in inches.
2. Actual size (conduit size).
Air Handler Voltage
Normal Operating
1
Voltage Range
1. Rated in accordance with ARI Standard 110, utilization range “A”.
208/230-1-60
187-253
