Table 5: Split unit installation
Point weights (lbs)
Total
Unit
1
2
3
4
5
6
7
8
Operat
ing
Shippi
ng
2 ton
138
76
66
112
75
70
72
112
675
715
3 ton
140
76
68
113
75
70
72
112
680
720
4 ton
151
147
127
129
97
93
100
130
950
1010
5 ton
160
156
136
138
98
94
101
138
990
1060
8 ton
292
252
236
270
73
108
140
99
1470
1560
10 ton
384
332
302
352
128
163
195
154
1940
2120
Ductwork
When installing ductwork, adhere to local codes. Where possible, minimize duct runs and avoid
abrupt changes in direction. Allow ample access space to service the coils and change the filters.
Perform regular maintenance on the ducts to increase the unit life, maintain efficient operation,
and reduce the accumulation of dust and debris.
To not exceed the maximum external static values, refer to the blower performance charts in Fan
Performance on page 28, engineer duct runs, and accessory pressure drop.
Louver sizing guidelines
An important issue in obtaining optimum performance from indoor air conditioners is proper
selection of the condenser intake and discharge louvers. In practice, outdoor air-cooled units intake
and discharge their cooling without restriction. However, indoor units must first overcome the
resistance of grilles or louvers at the outside wall and then the restriction of any interconnecting
ductwork.
The DSH's indoor air-cooled air conditioners are designed to accommodate the external static
pressure loss associated with properly sized storm proof louvers. A storm proof louver typically has
a free area approximately 40–45% of the actual louver size. To determine the free area required for
any given unit, adhere to the following guidelines:
•
The size condenser air intakes are for 350–600 feet/minute nominal velocity. The maximum
recommendation is 700 feet/minute.
•
The size condenser air discharge is for 1,200–1,500 feet/minute nominal velocity. The
maximum recommendation is 1,700 feet/minute.
Louvers with higher velocities than stated above can be employed. This is at the discretion of the
engineer or installer provided that the total air pressure drop does not exceed the capability of the
condenser fan and motor.
Low restriction louvers with shallow blade angles can allow higher face velocities without excessive
static pressure loss. Exceeding the static pressure capability of the condenser fan results in
insufficient condenser air volume. This causes a loss in system capacity and can cause compressor
shutdown during high ambient periods. Where applicable in such cases, the installation of an
oversize condenser motor/drive may be considered.
Note:
As a general rule, these velocities require an intake louver sized approximately 1.25
to 1.5 times the dimensions of the duct connection on the unit, and a discharge louver sized
approximately 1.5 to 2 times the duct connection dimensions
Model DSH024C–120C Horizontal R-410A Air Conditioning Units C-Generation Smart Equipment Controller
26
Johnson Controls
