NOTE: Add the operating charge of the condensing unit, the evaporator coil and
the refrigerant lines to determine the total refrigerant charge of the system.
1Charges are based on 40
°
F suction temperature and a 105
°
F liquid temperature.
2Type “L” copper tubing.
Model
Designation
Nominal
Capacity
(Tons)
Refrigerant
Flow Rate
1
(Lbs./Min.)
Type L
Copper Tubing
(Inches O.D.)
Pressure Drop
3
Friction
2
(PSI/100 Ft.)
Vertical
Rise
(PSI/Ft.)
180 Mbh
15
45
3/4
7/8
4.7
2.2
0.5
240 Mbh
20
60
3/4
7/8
8.0
3.5
0.5
1Based on Refrigerant-22 at the nominal capacity of the condensing unit, a liquid temperature of 105
°
F and a suction temperature of 40
°
F.
2
These friction losses do not include any allowances for a strainer, filter-drier, solenoid valve, isolation valve or fittings.
3
The total pressure drop of the liquid line for both friction and vertical rise must not exceed 40 PSI. If the pressure drop exceeds 40 PSI, the liquid refrigerant could flash before it reaches the
expansion valve. This flashing will not only cause erratic valve operation and poor system performance, but could also damage the expansion valve.
TABLE 5 - LIQUID LINES
Liquid Line
2
Inches, O.D.
5/8
0.113 lb./ft.
7/8
0.237 lb./ft.
Suction Line
2
Inches, O.D.
1-5/8
0.018 lb./ft.
2-1/8
0.031 lb./ft.
2-5/8
0.047 lb./ft.
TABLE 6 - REFRIGERANT-22 LINE CHARGE
1
Compressor Suction
Ambient Temperature Entering Condenser Coil (°F)
Model
65
75
85
95
105
115
Pressure
(psig)
Saturated
Temp (°F) MBH
1
kW
2
MBH
kW
MBH
kW
MBH
kW
MBH
kW
MBH
kW
54.9
30
165
12.3
157
13.4
150
14.8
142
16.3
134
18.1
126
19.9
61.6
35
181
12.5
172
13.6
164
15.0
156
16.5
147
18.3
138
20.2
180
68.5
40
196
12.7
188
13.9
179
15.3
170
16.7
160
18.6
151
20.4
76.0
45
212
12.9
204
14.1
194
15.5
184
17.0
174
18.9
164
20.8
84.0
50
231
13.2
220
14.3
210
15.8
199
17.3
188
19.1
177
21.0
54.9
30
228
17.3
217
19.2
206
21.1
195
23.4
183
25.9
172
28.5
61.6
35
248
17.7
237
19.6
225
21.5
213
23.8
200
26.4
188
29.0
240
68.5
40
269
18.1
257
20
244
21.9
231
24.3
218
26.9
204
29.6
76.0
45
291
18.5
277
20.5
264
22.4
250
24.8
236
27.5
222
30.3
84.0
50
313
19.0
299
21
284
23.0
269
25.3
254
28.1
239
30.9
1. Capacities are gross ratings.
2. Pow er is f or the condensing unit only.
TABLE 7 - CONDENSING UNIT COOLING CAPACITIES AND POWER REQUIREMENTS
550.23-N6Y
8
Unitary Products Group
