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.
Trane packages cooling capacity as a multiple of 12,000 BTU/hr (a two-digit code that divides by 12 to give tons). It shares its platform with American Standard under Trane Technologies.
Current models are non-hyphenated strings that begin with a refrigerant digit — 4 for R-410A/R-32, 2 for legacy R-22 — followed by T for the Trane brand. The third character marks the system: T (as in 4TTR) is a split air conditioner, W (4TWR) a heat pump. The capacity code sits at digits 7–8, so 4TTR6036 reads as 36 → 3.0 tons.
Older units begin with the letter T and carry a zero-padded three-digit capacity (e.g. TTR024 → 024 → 2.0 tons). The decoder strips the leading zero before mapping to tonnage.
The decoder above applies this nomenclature automatically. Capacity codes are nominal — always confirm against the rated-capacity line on the unit’s data plate.
Capacity decoding on this page follows Trane’s published model-number nomenclature. To confirm a unit’s actual rated capacity and efficiency, cross-check the authoritative references below.
Tonnage is derived from nominal cooling capacity: 1 ton of refrigeration = 12,000 BTU/hr.
Model-number conventions and standards evolve, and manufacturers occasionally reuse digits for non-capacity codes — the rated-capacity line on the unit’s data plate is always authoritative. Figures here are for identification and planning, not a substitute for a professional load calculation.
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.