R454B Charging Information and Procedures
This document provides essential charging information for R454B refrigerant systems, detailing methods such as subcooling and weigh-in, and includes comprehensive tables for indoor unit matchups, charge levels, and normal operating pressures.
Charging Methods
Maintenance checks can be performed using the Normal Operating Pressures table. However, this table is not a procedure for charging the system. Minor variations in pressures are expected due to installation differences, but significant deviations may indicate improper charging or system issues.
Charge Using the Subcooling Method
Cooling Mode: When the outdoor ambient temperature is 60°F (15°C) and above, use the cooling mode to adjust the charge using the subcooling method. Target subcooling values in Table 1 are based on 70 to 80°F (21-27°C) indoor return air temperature.
Heating Mode: When the outdoor ambient temperature is below 60°F (15°C), use the heating mode to adjust the charge using the subcooling charge levels (table). Target subcooling values in Table 1 are based on 65-75°F (18-24°C) indoor return air temperature.
Table 1 - Normal Operating Pressures
*Temperature of air entering the outdoor coil.
| °F* | LIQ / VAP | LIQ / VAP | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| 20 | 30 | 40 | 50 | 60 | 65 | 75 | 85 | 95 | 105 | 115 | |
| -018 | 268/60 | 285/75 | 301/93 | 318/112 | 336/132 | 213/130 | 248/132 | 288/135 | 332/138 | 382/139 | 436/140 |
| -024 | 272/59 | 285/73 | 298/89 | 316/106 | 335/125 | 222/129 | 259/131 | 300/133 | 346/136 | 398/138 | 455/139 |
| -030 | 278/54 | 294/68 | 313/84 | 329/102 | 348/120 | 221/128 | 259/130 | 300/133 | 345/135 | 395/137 | 450/139 |
| -036 | 257/47 | 281/67 | 299/83 | 315/100 | 332/120 | 213/124 | 249/129 | 290/131 | 334/133 | 383/135 | 436/137 |
| -042 | 285/56 | 302/70 | 318/86 | 334/103 | 351/122 | 214/123 | 249/129 | 289/131 | 333/133 | 382/135 | 435/137 |
| -048 | 287/56 | 305/69 | 322/84 | 339/101 | 357/120 | 221/118 | 258/125 | 299/127 | 346/130 | 396/132 | 449/135 |
| -060 | 284/54 | 301/67 | 315/79 | 333/99 | 349/116 | 227/121 | 265/124 | 307/126 | 353/128 | 403/133 | 459/132 |
Line Set Length Adjustments and Weigh-in Method
Table 2 lists Lennox recommended indoor unit matchups with charge levels for various outdoor unit sizes. Charge levels on the unit nameplate are based on installations with 30ft. (9.1m) line sets. For line sets with 3/8" (9.5mm) liquid line, add 3 oz. additional refrigerant for every 5ft. longer than 30ft. If line length is less than 30ft., subtract this amount (refer to Installation Instructions for more details).
Charge Using the Weigh-in Method
If the system is void of refrigerant, locate and repair any leaks, then weigh in the refrigerant charge into the unit. For charge adjustments, consider line set length differences and, referring to Table 1, adjust for the matchup difference.
- Recover the refrigerant from the unit.
- Conduct leak check; evacuate as previously outlined.
- Weigh in the unit nameplate charge, adjusting for matchup and line set length differences.
If weighing facilities are not available, use the Subcooling method.
Table 2 – Indoor Unit Matches and Subcooling Charge Levels and Additional Charge
**Amount of charge required in addition to charge shown on unit nameplate.
| Indoor Matchup | Target Subcool | Total Charge | Additional Charge | Indoor Matchup | Target Subcool | Total Charge | Additional Charge | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Heat (±5°F) | Cool (±1°F) | lbs | oz | lbs | oz | Heat (±5°F) | Cool (±1°F) | lbs | oz | lbs | oz | |||
| ML14KP1-018 / EL16KP1-018 | ML14KP1-042 / EL16KP1-042 | |||||||||||||
| CBK45UHPT-018/ CBK45UHVT-018 | 12 | 7 | 6 | 3 | 1 | 3 | CBK45UHPT-042/ CBK45UHET-042/ CBK45UHVT-042 | 13 | 4 | 9 | 2 | 0 | 4 | |
| CBK45UHPT-024/ CBK45UHET-024/ CBK45UHVT-024 | 11 | 7 | 6 | 6 | 1 | 6 | CBK45UHET-048/ CBK45UHVT-048 | 12 | 4 | 9 | 7 | 0 | 9 | |
| CBK47UHET-018/ CBK47UHET-024/ CBK48MVT-018/024 | 6 | 7 | 7 | 0 | 2 | 0 | CBK47UHET-042/ CBK48MVT-042 | 12 | 6 | 9 | 13 | 0 | 15 | |
| CK40[C,U]-24 | 11 | 3 | 5 | 3 | 0 | 3 | CBK47UHET-048/CBK48MVT-048 | 11 | 6 | 9 | 10 | 0 | 12 | |
| CK40[C,U]-30 | 11 | 7 | 5 | 11 | 0 | 11 | CK40[C,U]-48 | 14 | 5 | 9 | 5 | 0 | 7 | |
| CK40HT-24A | 12 | 4 | 5 | 1 | 0 | 1 | CK40[C,U]-49 | 7 | 5 | 9 | 7 | 0 | 9 | |
| CK40HT-24B | 15 | 7 | 5 | 15 | 0 | 15 | CK40HT-42B | 8 | 5 | 10 | 2 | 1 | 4 | |
| CK40HT-30A | 12 | 3 | 5 | 2 | 0 | 2 | CK40HT-42C | 24 | 5 | 9 | 11 | 0 | 13 | |
| CK40HT-30B | 10 | 8 | 5 | 0 | 0 | 0 | CK40HT-48B | 1 | 8 | 6 | 8 | 14 | 0 | 0 |
| CK40DT-30/36 | 28 | 7 | 6 | 8 | 1 | 8 | CK40HT-48C | 25 | 6 | 9 | 13 | 0 | 15 | |
| ML14KP1-024 / EL16KP1-024 | CK40DT-48C | 44 | 6 | 9 | 1 | 0 | 3 | |||||||
| CBK45UHPT-024/ CBK45UHET-024/ CBK45UHVT-024 | 9 | 7 | 6 | 11 | 0 | 15 | CK40DT-50/60C | 43 | 6 | 10 | 3 | 1 | 5 | |
| CBK45UHPT-030/ CBK45UHET-030/ CBK45UHVT-030 | 4 | 6 | 7 | 5 | 1 | 9 | ML14KP1-048 / EL16KP1-048 | |||||||
| CBK47UHET-024/CBK48MVT-018/024 | 12 | 9 | 6 | 12 | 1 | 0 | CBK45UHET-048/ CBK45UHVT-048 | 11 | 5 | 9 | 0 | 0 | 1 | |
| CBK47UHET-030/ CBK48MVT-030 | 9 | 9 | 6 | 8 | 0 | 12 | CBK45UHET-060/ CBK45UHVT-060 | 10 | 7 | 8 | 15 | 0 | 0 | |
| CK40[C,U]-24 | 11 | 7 | 6 | 2 | 0 | 6 | CBK47UHET-048/CBK48MVT-048 | 13 | 5 | 9 | 9 | 0 | 10 | |
| CK40[C,U]-30 | 10 | 10 | 6 | 15 | 1 | 3 | CBK47UHET-060/CBK48MVT-060 | 13 | 7 | 10 | 2 | 1 | 3 | |
| CK40HT-24A | 13 | 8 | 6 | 4 | 0 | 8 | CK40[C,U]-48 | 17 | 5 | 9 | 3 | 0 | 4 | |
| CK40HT-24B | 13 | 7 | 5 | 13 | 0 | 1 | CK40[C,U]-49 | 8 | 5 | 9 | 0 | 0 | 1 | |
| CK40HT-30A | 12 | 7 | 6 | 4 | 0 | 8 | CK40[C,U]-50/60C | 20 | 5 | 10 | 2 | 1 | 3 | |
| CK40HT-30B | 7 | 7 | 5 | 12 | 0 | 0 | CK40[C,U]-60C | 10 | 5 | 10 | 2 | 1 | 3 | |
| CK40DT-30/36 | 14 | 5 | 6 | 14 | 1 | 2 | CK40HT-48B | 20 | 5 | 9 | 15 | 1 | 0 | |
| ML14KP1-030 / EL16KP1-030 | CK40HT-48C | 21 | 5 | 10 | 13 | 1 | 14 | |||||||
| CBK45UHPT-030/ CBK45UHET-030/ CBK45UHVT-030 | 9 | 7 | 7 | 10 | 0 | 10 | CK40HT-51/61C | 14 | 6 | 10 | 15 | 2 | 0 | |
| CBK45UHPT-036/ CBK45UHET-036/ CBK45UHVT-036 | 8 | 7 | 7 | 10 | 0 | 10 | CK40HT-60D | 12 | 5 | 11 | 5 | 2 | 6 | |
| CBK47UHET-030/ CBK48MVT-030 | 15 | 8 | 8 | 1 | 1 | 1 | CK40DT-50/60C | 49 | 6 | 10 | 14 | 1 | 15 | |
| CBK47UHET-036/ CBK48MVT-036 | 18 | 9 | 8 | 4 | 1 | 4 | CK40DT-60D | -- | -- | -- | -- | -- | -- | |
| CK40[C,U]-30 | 15 | 2 | 7 | 3 | 0 | 3 | ML14KP1-060 / EL16KP1-060 | |||||||
| CK40[C,U]-36 | 14 | 7 | 7 | 10 | 0 | 10 | CBK45UHET-060/ CBK45UHVT-060 | 12 | 6 | 9 | 15 | 0 | 0 | |
| CK40HT-30A | 21 | 9 | 7 | 0 | 0 | 0 | CBK47UHET-060/CBK48MVT-060 | 12 | 7 | 10 | 7 | 0 | 8 | |
| CK40HT-30B | 15 | 5 | 8 | 0 | 1 | 0 | CK40[C,U]-49 | 14 | 7 | 10 | 11 | 0 | 12 | |
| CK40HT-36A | 21 | 3 | 7 | 4 | 0 | 4 | CK40[C,U]-60C | 14 | 7 | 10 | 13 | 0 | 14 | |
| CK40HT-36B | 24 | 6 | 7 | 5 | 0 | 5 | CK40[C, U]-60D | 22 | 5 | 11 | 9 | 1 | 14 | |
| CK40HT-36C | 13 | 5 | 7 | 8 | 0 | 8 | CK40HT-51/61C | 20 | 7 | 10 | 9 | 0 | 10 | |
| CK40DT-42 | 34 | 7 | 7 | 1 | 0 | 1 | CK40HT-60D | 11 | 6 | 10 | 12 | 0 | 13 | |
| ML14KP1-036 / EL16KP1-036 | CK40DT-60D | 47 | 7 | 10 | 9 | 0 | 10 | |||||||
| CBK45UHPT-036/ CBK45UHET-036/ CBK45UHVT-036 | 12 | 4 | 7 | 11 | 0 | 0 | ||||||||
| CBK45UHPT-042/ CBK45UHET-042/ CBK45UHVT-042 | 11 | 4 | 9 | 0 | 1 | 5 | ||||||||
| CBK47UHET-036/ CBK48MVT-036 | 15 | 4 | 8 | 15 | 1 | 4 | ||||||||
The values in this table are most popular match-up pressures; indoor match-up, indoor air quantity, and indoor load will cause the pressures to vary.
