YORK YVWA Variable-Speed Screw Chiller
Variable-speed water-cooled screw chiller with 50% fewer moving parts than slide-valve competitors, offering continuous 12.5% turndown and up to 30% better real-world efficiency.
The YORK YVWA is a water-cooled, variable-speed screw chiller covering approximately 125 to 300 TR (440–1,055 kW) — the mid-range bracket where many airport ancillary buildings, cargo terminals, MRO hangars and remote concourse facilities fall. Both semi-hermetic twin-screw compressors use a direct variable-speed drive with no slide valves or unloading steps, which removes the mechanical unloading mechanisms responsible for elevated wear in conventionally controlled screw machines.
The elimination of unloading steps delivers two concrete benefits: continuous capacity modulation from 100% down to 12.5% of full load, and 50% fewer moving parts relative to fixed-speed screw chillers with slide valves. The proprietary falling-film evaporator reduces refrigerant charge by up to 30% compared to flooded designs, improving both efficiency and leak-risk profile. Refrigerant is HFC-134a with zero ozone depletion potential; the unit is compatible with open or closed-circuit cooling towers, dry air coolers, and adiabatic coolers.
The YVWA's real-world efficiency advantage — Johnson Controls cites up to 30% improvement against earlier-generation products — is most evident at the low-to-medium partial loads typical of commercial air-conditioning during non-peak hours. For GCC facilities where cooling loads fluctuate sharply between morning pre-conditioning, peak mid-day occupancy and overnight setback, the continuous VSD turndown avoids the efficiency cliff that fixed-speed screw chillers encounter below 50% load.
Technical specifications.
| Cooling Capacity Range | 125–300 TR |
| Cooling Capacity Range (kW) | 440–1,055 kW |
| Minimum Turndown | 12.5% |
| Moving Parts Reduction vs Slide-Valve | 50% |
| Real-World Efficiency Improvement vs Previous Generation | Up to 30% |
| Refrigerant Charge Reduction vs Flooded | Up to 30% |
| Refrigerant | HFC-134a |
| Compressor Type | Semi-hermetic twin-screw, variable-speed direct drive |
| Evaporator Type | Falling-film, hybrid design |
| Condenser Compatibility | Open/closed-circuit cooling towers, dry air coolers, adiabatic coolers |
Use cases.
- ›Airport ancillary building HVAC — cargo terminals, maintenance facilities, remote concourses
- ›Mid-size office and retail zones within airport landside developments
- ›MRO hangar facilities requiring reliable year-round chilled water
- ›Data rooms and server suites with continuous but variable cooling loads
- ›Retrofit replacement of fixed-speed screw plant where improved part-load efficiency is the primary driver
- ›Facilities preferring oil-bearing screw technology for operational familiarity alongside improved efficiency