Digits 7–8 in 4TT model numbers are the BTU code. Paste your model number for an instant decode.
Always confirm against the data plate's rated capacity line — model ranges occasionally reuse digits for non-capacity codes, and the plate is authoritative.
| Capacity code | BTU/hr | Tons |
|---|---|---|
| 09 | 9,000 | 0.75 |
| 12 | 12,000 | 1.0 |
| 18 | 18,000 | 1.5 |
| 24 | 24,000 | 2.0 |
| 30 | 30,000 | 2.5 |
| 36 | 36,000 | 3.0 |
| 42 | 42,000 | 3.5 |
| 48 | 48,000 | 4.0 |
| 60 | 60,000 | 5.0 |
Amana American Standard Blue Star Bryant Carrier Daikin Goodman Heil Hitachi Lennox LG Lloyd O General Panasonic Payne Rheem Ruud Samsung Voltas Whirlpool York
On the data plate — a metal or foil sticker on the side or back of the outdoor unit (or behind the front panel on indoor split units). Use the model number, not the serial number, which encodes the manufacture date rather than capacity.
Digits 7–8 in 4TT model numbers are the BTU code. Divide the BTU code by 12 to get tons.
Paste the model number from the outdoor unit's data plate into the decoder above — it applies Trane's nomenclature automatically. Example: 4TTR4036 = 3.0 tons.
Different brand? Back to the full 22-brand decoder. Sizing a replacement? Check what your space really needs with the AC tonnage calculator first — the old unit may have been mis-sized.