Filter
Top Products
6 18-AC56D1-1
Installer’s Guide
SUBCOOLING CHARGING IN COOLING ABOVE 55°F OD AMBIENT
The Trane company has always recommended installing
Trane approved
matched indoor and outdoor systems.
All 13 SEER Trane split systems are ARI rated with only
TXV indoor systems.
The benefits of installing approved indoor and outdoor split
systems are maximum efficiency, optimum performance and
the best overall system reliability.
The following charging methods are therefore prescribed for
systems with indoor TXVs.
1. Subcooling (in the cooling mode) is the
only recommended
method of charging above 55°F ambient temperatures.
2. For best results - the indoor temperature should be kept
between 70°F to 80°F. Add system heat if needed.
3. At start-up, or whenever charge is removed or added, the
system must be operated for a minimum 20 minutes to
stabilize before accurate measurements can be made.
4. Measure Liquid Line Temperature and Refrigerant
Pressure at service valves.
5. Determine total refrigerant line length, and height (lift)
if indoor section is above the condenser.
6. Determine the Design Subcool Charging Temperature
from the unit nameplate.
7. Locate this value in the appropriate column of the
Subcooling Charging Table. Locate your liquid line
temperature in the left column of the table, and the
intersecting liquid line pressure under your nameplate
subcool value column. Add refrigerant to raise the pres-
sure to match the table, or remove refrigerant to lower
the pressure. Again, wait 20 minutes for the system
conditions to stabilize before adjusting charge again.
8. When system is correctly charged, you can refer to
System Pressure Curves (in Service Facts) to verify
typical performance.
Installer’s Guide
R-22 SUBCOOLING CHARGING TABLE
LIQUID
TEMP.
(°F)
DESIGN SUBCOOLING VALUES (°F)
8101214
LIQUID LINE PRESSURE (psi)
45 89 93 96 100
50 98 102 105 109
55 107 111 115 119
60 117 121 126 130
65 128 132 137 141
70 139 144 148 153
75 151 156 161 166
80 163 168 174 179
85 176 182 187 193
90 190 196 202 208
95 205 211 217 223
100 220 226 233 239
105 236 243 249 256
110 253 260 267 274
115 271 278 285 293
120 289 297 305 313
125 309 317 325 333
SUBCOOL CHARGING TABLE CORRECTIONS FOR LINE LENGTH AND RISE
60
50
40
30
25
Add 5 psig to Subcool Charging Table Pressure
20
15
Use Design Subcool Value from Table
10
0
Subtract 5 psig from S.C. Table Pressure
10 20 25 30 40 60 80
TOTAL REFRIGERANT LINE LENGTH (FEET)
REFRIGERANT
LINE LIFT (FEET)