STULZ CyberAir 3PRO
One model name spans DX, dual-fluid, and chilled water; the suffix decides 2027 EPA exposure
This model is part of SecondWatt’s crac / crah research catalogue. Specifications and price observations are included where supported by sources. Equipment availability and commercial terms require confirmation.
Room and in-row air cooling runs out of headroom as rack density rises; above roughly 40 kW per cabinet the load is picked up by liquid cooling, usually retrofitted into halls that keep their CRAC units for the remaining air-cooled rows. The catalogue entries closest to that decision are CoolIT Systems DCLC Direct Liquid Cooling and GRC ICEtank Immersion Cooling.
STULZ CyberAir 3PRO specs, capacity in kW and tons, DX refrigerant options, GWP values, and the 2027 EPA and EU F-Gas deadlines for used equipment buyers.
CyberAir 3PRO is a family name, not a single SKU. Model codes combine an air-conduction prefix, a size class, and a cooling-system suffix, and that suffix is the whole story: A/AS, G, and GE/GES all carry a compressor and refrigerant circuit, while CW and CW2 are pure chilled-water coils with none at all. ACW and GCW sit in between, pairing a chilled-water primary path with a DX backup circuit in one cabinet.
The nameplate alone settles nothing until that suffix is read. DX capacity spans 22-150 kW (6.3-42.7 tons) across all five DX variants; CW spans 22-260 kW (6.3-73.9 tons) on STULZ's own product page. Both sides use scroll compressors, either fixed-speed on/off units or STULZ's continuously modulated "EC compressor," with EER around 4.3-5.5 kW/kW.
Five refrigerants populate the DX lineup and split on the 2027 deadline. R-407C, R-410A and R-134a all exceed EPA's 700 GWP ceiling for new CRAC manufacture; R-513A (GWP 630) already clears it on the on/off-compressor ASD/ASU/ALD/ALU series, and R-454C (GWP 146) clears it comfortably on the newer GE4(S) range. The EU's stricter F-Gas Regulation 2024/573 caps new data-center AC at GWP 150 on the same date, a ceiling R-513A fails despite passing EPA's, leaving only R-454C compliant on both.
STULZ is the one name in this category never absorbed into a larger industrial group, founded in Hamburg in 1947 and still family-held, and it shipped EC fans as standard on its CyberAir 1 in 2003. A same-vintage Liebert unit was more likely built with belt-driven fans; Vertiv still sells a paid retrofit kit to convert those units today.
Why it matters
The model-code suffix, not the product name, decides whether a unit has refrigerant exposure at all and, on the DX side, whether it already clears EPA's 700 GWP limit taking effect January 1, 2027. R-513A clears that US limit today; the EU's stricter 150 GWP F-Gas ceiling on the same date fails R-513A and passes only R-454C, so a unit compliant in one market can fail the other.
Who buys it
Data center and colocation operators sourcing room-perimeter CRAC or CRAH capacity, telecom and edge site owners standardizing on one European brand across DX and chilled-water rooms, and buyers working European used-equipment channels where STULZ resale activity concentrates. A buyer must confirm the suffix on the physical nameplate before pricing, since "CyberAir 3PRO" alone names neither a compressor nor a refrigerant.
Role in the data center
Room-perimeter cooling for a data hall, server room, or telecom space, sized well above in-row or rack-level units and below large central chiller-plant equipment. The DX variants (A/AS, G, GE/GES, ACW, GCW) serve rooms without or supplementing a chilled-water plant; the CW/CW2 variants serve rooms already fed by a central chiller.
Key specifications
| Cooling capacity, DX line (all variants) | 22-150 kW (6.3-42.7 tons) |
|---|---|
| Cooling capacity, CW line (product-page figure) | 22-260 kW (6.3-73.9 tons) |
| Cooling capacity, GE4(S) low-GWP DX | 24-71 kW (6.8-20.2 tons) |
| Airflow, DX line | 4,000-32,000 m3/h |
| Airflow, CW line | 7,500-46,200 m3/h |
| Electrical supply, standard (EU/international) | 400 (380-415) / 3-phase+N+PE / 50 V, Hz |
| Electrical supply, alternate options | 230V/3Ph/50Hz; 208V/3Ph/60Hz; 460V/3Ph/60Hz V, Hz |
| Dimensions, smallest cabinet (size 1) | 950 (W) x 1,980 (H) x 890 (D) mm |
| Dimensions, largest cabinet (size 7) | 3,110-3,350 (W) x 2,495-2,915 (H) x 980-1,040 (D) mm |
| Operating weight, ASD 231 A (DX, air-cooled) | 376 kg |
| Operating weight, ASU 640 CW (chilled water) | 373 kg |
| Sound pressure level range | 46-58.5 dB(A) |
| Filter class | ISO 16890 (ISO Coarse 80% to ePM10 70%) rating |
| EER, compressor mode (headline range) | 4.3-5.5 kW/kW |
| EER, ASD 231 A at 53C condensing temp (unit example) | 2.96 kW/kW |
| Standards compliance (DX) | EN 378, EN ISO 12100, EC Machinery Directive 2006/42/EC, RoHS 2011/65/EU - |
Technical summary
DX capacity: 22-150 kW (6.3-42.7 tons). CW capacity: 22-260 kW (6.3-73.9 tons), OEM sources disagree up to 272.8 kW. GE4(S) low-GWP DX capacity: 24-71 kW (6.8-20.2 tons). Compressor: scroll, on/off or continuously modulated "EC compressor". EER, compressor mode: 4.3-5.5 kW/kW. Refrigerants: R-407C, R-410A, R-134a, R-513A, R-454C. Electrical supply: 400V (380-415V) / 3-phase+N+PE / 50 Hz standard. Fan technology: RadiCal EC fans, latest generation. EPA CRAC-subsector GWP limit: 700, effective January 1, 2027. EU F-Gas 2024/573 self-contained data-center AC limit: GWP 150, same date.
Major variations
CyberAir 3PRO ships as five DX cooling systems plus a separate chilled-water line, all under one product name. A/AS is air-cooled DX, G is water-cooled DX, and GE/GES is hybrid free-cooling DX; all three carry a compressor and refrigerant circuit. ACW and GCW are dual-fluid variants pairing a chilled-water primary path with an air-cooled or water-cooled DX backup circuit in the same cabinet, and STULZ does not state which refrigerant charges that backup circuit. CW and CW2 are the pure chilled-water line, single or dual redundant circuit, with no compressor or refrigerant at all. A sixth range, GE4(S), is a newer low-GWP hybrid free-cooling DX built on R-454C specifically to meet the EU's F-Gas Regulation 2024/573, available in three sizes from 24-71 kW.
Configurations and options
Air-conduction prefix (ASD downflow, ASU upflow, ASR raised-floor with external fan box) combines with the cooling-system suffix and a numeric size class to form the full model code. On/off fixed-speed compressors run on the ASD/ASU and ALD/ALU series; STULZ's continuously modulated "EC compressor" runs on AS and GES systems. Alternate voltages (230V/3Ph/50Hz, 208V/3Ph/60Hz, 460V/3Ph/60Hz) are available against the 400V/50Hz standard configuration.
Compatibility and dependencies
A buyer should not assume "CyberAir" branding alone identifies this model: STULZ separately sells CyberAir 2 (the direct predecessor), CyberAir Mini/Mini CW, CyberOne (a distinct EC-DX line), CyberRow, CyberPack, Ceilair, and EVE (an Italian-subsidiary line), and a listing that hedges between "CyberAir" and one of these names should not be priced as CyberAir 3PRO without a confirmed ASD/ASU/ASR/ACW/GCW/CW/CW2 model code on the nameplate.
Pricing and availability
Comparable secondary-market band: 75–700 $ per ton. Trend: stable Lead time, new: Neither STULZ nor its dealers state a lead time in days or weeks; the Lendoux.com new-unit listing shows dealer stock on hand rather than a manufacturing lead time.. Lead time, used or refurbished: No dealer or classified publishes a numeric used-unit lead time; used units observed are existing deinstalled or dealer inventory, so availability is a function of rigging and freight rather than a manufacturing queue.. Warranty, new: STULZ publishes no new-unit warranty term for the CyberAir 3PRO as of August 2026.. Warranty, used: No used-unit warranty is published by STULZ or its dealers as of August 2026..
Lifecycle and maintenance
No STULZ document publishes a numeric service-life, MTBF, or overhaul interval for CyberAir 3PRO. The continuity case is concrete, not asserted: STULZ is the one major name in this category never absorbed into a larger industrial group, founded in Hamburg in 1947 and still family-held, and it shipped EC fans as standard on its CyberAir 1 as early as 2003, so its EC-fan and driver-board failure history run longer than any competitor's. Vertiv's own Liebert lineup shows the contrast: legacy DS, DH, and Deluxe System/3 units shipped with belt-driven AC fans, and Vertiv still sells a paid EC Fan Upgrade Service to retrofit them today. A 15-year-old STULZ unit's parts and control-board sourcing run through the same unbroken entity that built it, not a post-acquisition successor brand.
Thermal and emissions profile
Five refrigerants span STULZ's CyberAir 3PRO DX lineup: R-407C (GWP 1,774), R-410A (2,088), and R-134a (1,430) all exceed EPA's 700 GWP ceiling for new CRAC manufacture after January 1, 2027; R-513A (630, on the on/off-compressor ASD, ASU, ALD and ALU series) already clears it; R-454C (146, on the GE and GES "GE4(S)" range) clears it comfortably. The EU's F-Gas Regulation 2024/573 is stricter on the same date, capping new self-contained data-center AC at GWP 150 - R-513A fails that ceiling despite passing EPA's, leaving R-454C as the only refrigerant compliant in both markets. CW and CW2 units carry no refrigerant circuit at all; their exposure sits upstream at the chiller plant.
Common failure points
- Scroll compressor — rising amp draw at constant load, reduced sensible capacity, high-head-pressure trips
- Refrigerant circuit leak points — repeated small refrigerant top-offs, declining subcooling on successive service visits
- EC fan driver board — fan fails to modulate, runs fixed-speed or not at all despite an intact motor
- E2 controller firmware and comms card — BMS integration errors, lost setpoint history, obsolete Modbus or BACnet card
- Condenser and evaporator coil fouling — falling sensible capacity and rising head pressure at unchanged load over time
- Humidifier and reheat subsystem — subsystem bypassed or physically disconnected, canister corrosion, no humidity control
- Backup DX circuit on ACW or GCW units — backup circuit sits idle for years while the primary chilled-water path carries the load
Inspection checklist
Nameplate refrigerant charge: confirm R-407C, R-410A, R-134a, R-513A, or R-454C: the five options span GWP 146 to 2,088 and only two clear EPA's 700 GWP limit. Model code suffix: confirm A, AS, G, GE, GES, ACW, or GCW versus CW or CW2: a CW/CW2 nameplate carries zero refrigerant exposure, an ACW/GCW nameplate hides a backup DX circuit. Compressor run-hours: pull the on-board E2 controller counter reading, not a verbal estimate, before rigging. Refrigerant leak-rate history: request 3 years of service tickets with logged superheat and subcooling readings, not a single spot check. Superheat at the evaporator outlet: verify it falls within 8-12F of design at the last recorded service: a wide deviation signals a metering-device or charge problem.
Procurement channels
New-unit pricing comes through a European dealer (Lendoux.com) rather than directly from STULZ. Used units circulate through German-language classifieds and dealer sites (Permasale.de, Kleinanzeigen.de); English-language US marketplaces carry no CyberAir 3PRO listings at all.
Regional notes
STULZ's own catalog splits by regulator, not just by refrigerant. Against EPA's 700 GWP limit on CRAC-subsector manufacture from January 1, 2027, R-513A (GWP 630) already clears the bar on the on/off-compressor ASD, ASU, ALD and ALU series. Against the EU's F-Gas Regulation 2024/573, which caps new self-contained data-center AC at GWP 150 on the same date, that same R-513A fails by a wide margin and only R-454C (GWP 146) passes. A buyer sourcing across both markets, or moving a European-built unit to a US site or the reverse, cannot assume one region's compliant refrigerant satisfies the other.