Trane Sintesis RTAF
Air-cooled helical-rotary screw chiller, 115-520 tons, oil-lubricated, three-way refrigerant choice
Trane Sintesis RTAF is one of 5 chillers tracked in the SecondWatt catalogue, each with specifications, lead times and indicative secondary-market pricing.
Chilled water is only the upstream half of a high-density cooling loop: once heat is picked up at the die rather than in the room, the plant feeds coolant distribution units and immersion tanks tracked under liquid cooling, which run off the same chilled-water supply as the units on this page. The catalogue entries closest to that decision are ZutaCore HyperCool Two-Phase Immersion and GRC ICEtank Immersion Cooling.
Trane Sintesis RTAF air-cooled screw chiller: verified specs, refrigerant GWP compliance, inspection checklist, and secondary-market pricing status.
Trane's air-cooled, oil-lubricated helical-rotary (twin-screw) chiller ships as model RTAF, marketed since 2015 as Sintesis, rebranded in current European catalogs as Sintesis Prime RTAF. North American capacity runs 115-520 nominal tons; EMEIA catalogs list the platform from 300-2,090 kW. RTAF did not replace Trane's older Series R screw lines: RTAC (140-500 tons, R-134a only) and the earlier RTAA (70-400 tons, originally R-22) both still sit on Trane's price list, with RTAC a current, cheaper, parallel offering rather than a discontinued predecessor. A second, unrelated machine complicates the picture: Trane also sells Sintesis eXcellent, model GVAF, which uses magnetic-bearing centrifugal compressors, not screws, standard on R-1234ze(E) from a French factory. Trane expanded GVAF to 2.5 MW in April 2026, explicitly for data centers, the same buyers RTAF targets. A quote or listing that says only "Sintesis" does not identify compressor architecture by itself, so confirming RTAF versus GVAF on the nameplate is the single most consequential identification step in this family. Refrigerant is a factory-time choice, not a fixed spec: North American RTAF ships on R-134a or R-513A since 2015, while EMEIA adds a third option, R-1234ze(E), on the RTAF-G sub-line. R-513A (GWP about 630) and R-1234ze(E) (GWP under 5) both clear the EPA's 700 GWP comfort-cooling limit effective January 1, 2025; R-134a (GWP 1,430) does not. Trane states converting an installed unit from R-134a to R-513A is offered only in Europe, making a used R-134a unit a refrigerant dead end domestically.
Why it matters
RTAF's three-way refrigerant choice is the commercial hinge: R-513A and R-1234ze(E) clear the EPA's 700 GWP comfort-cooling limit, R-134a does not, and North America has no documented in-region path to convert an R-134a unit to R-513A after the fact. Free cooling and refrigerant are both locked in at the factory via model-number digits, so a used RTAF's full configuration string, not just its tonnage, decides whether it substitutes for another unit of the same nominal size.
Who buys it
Data center operators and colocation developers specify RTAF for chilled-water plants where a condenser-water loop is not practical, often paired with the factory free-cooling option chosen at order time. Hospitals, universities, and commercial campuses buy mid-range RTAF tonnages for comfort cooling. Process-cooling buyers select the dedicated RTAF-G Process variant. An EMEIA buyer wanting the lowest refrigerant GWP orders RTAF-G on R-1234ze(E), unlisted in North America.
Key specifications
| Capacity range (North America) | 115-520 nominal tons |
|---|---|
| Capacity range (EMEIA, RTAF-G) | 320-1,720 kW |
| Refrigerant (North America) | R-134a or R-513A |
| Refrigerant (EMEIA) | R-134a, R-513A, or R-1234ze(E) |
| R-513A GWP | 630 AR5-basis |
| R-1234ze(E) GWP | under 5 (Trane states <1 and also 4 in different documents) |
| Full-load EER (EMEIA RTAF-G, XSE) | 3.53-3.80 kW/kW (EU convention) |
| Compressor type and count | Semi-hermetic, direct-drive helical-rotary (twin) screw; 2 (115-270T), 3 (280-390T), or 4 (410-520T) per unit count |
| Evaporator type | Shell-and-tube, CHIL (Compact-High performance-Integrated-Low charge); 2-pass at or below 270T, 1-pass 280-520T |
| Electrical supply (North America) | 380/60/3, 400/50/3, 460/60/3, 575/60/3 V/Hz/phase |
| Operating weight (North America) | 8,091 (115T) - 23,907 (500T) lb |
| Operating weight (EMEIA, RTAF-G) | 3,410-9,840 kg |
| Sound level (EMEIA RTAF-G, by acoustic package) | 91-103 dB(A) |
| Minimum ambient operating temperature (North America) | 14 standard; -4 with low-ambient option F |
| Ambient operating range (EMEIA, high-ambient option) | -10 to +55 C |
| Free-cooling configuration | Factory-installed only, selected at order via model-number digit (Total/Partial x Direct/Glycol-Free); no field-add path documented |
Technical summary
Capacity, North America: 115-520 nominal tons Capacity, EMEIA RTAF-G: 320-1,720 kW Refrigerant, North America: R-134a or R-513A Refrigerant, EMEIA: R-134a, R-513A, or R-1234ze(E) R-513A GWP: approximately 630 R-1234ze(E) GWP: under 5 across Trane figures (as low as <1) Compressor: oil-lubricated helical-rotary twin screw, 2-4 per unit Evaporator: shell-and-tube CHIL design, low refrigerant charge Electrical supply: 380/400/460/575V, 50/60Hz, 3-phase Operating weight, North America: 8,091-23,907 lb Sound level, EMEIA: 91-103 dB(A) by acoustic package Free cooling: factory-installed only, chosen at order
Configurations and options
Refrigerant is a factory build-time choice: R-134a or R-513A in North America, with R-1234ze(E) added as a third option in EMEIA on the RTAF-G sub-line. Compressor count scales with frame size: 2 compressors for 115-270 ton units, 3 for 280-390 tons, 4 for 410-520 tons, each unit built with two independent refrigerant circuits. Free cooling is a factory-installed option only, selected at order via a model-number digit across Total/Partial and Direct/Glycol-Free configurations. Sound packages in EMEIA literature span Standard through Extra/Whisper-Low-Noise tiers, roughly 91 to 103 dB(A).
Compatibility and dependencies
Free cooling cannot be added in the field: a unit ordered without the free-cooling digit in its model number has no documented retrofit path, so two used RTAF units of identical tonnage are not automatically interchangeable if one has factory free-cooling and the other does not. Refrigerant is similarly locked at the factory, and Trane's own oil-compatibility rules state that the wrong oil type in the wrong refrigerant circuit causes catastrophic failure, ruling out an informal field refrigerant swap. Acoustic package is also fixed at build time and is not a field-retrofit option.
Pricing and availability
Comparable secondary-market band: 123.33–136 $ per ton. Trend: flat
Common failure points
- Twin-screw rotor set — Rising discharge temperature and falling volumetric efficiency, confirmed by a climbing Fe/Cu wear-metal count on oil analysis
- Discharge and suction bearings — Vibration-spectrum peaks at bearing-pass frequency, often preceding audible grinding by months
- Slide valve / Variable Volume Index mechanism — Compressor will not load past a fixed capacity step, or hunts between steps
- Oil separator and oil circuit — Recurring low-oil-flow fault trips on the controller, or oil carryover in the sight glass
- Aluminum-alloy condenser coil — Bent fins, hail-guard damage, or a white corrosion film that cuts rated heat-rejection capacity
- Symbio 800 control board — Obsolete firmware revision, an unavailable replacement board, or loss of BACnet/LonTalk/Modbus integration
- Refrigerant circuit and seals — Annualized leak rate above roughly 10 percent of full charge, or frost and oil residue at joints