Scroll Chillers Explained: Working, Types & Applications
Scroll chillers are the smallest and simplest of the mainstream chiller compressor types — and for buildings under roughly 100 TR of cooling load, they’re often the most cost-effective choice. This guide covers how they work, where they fit, and how they compare to screw and centrifugal chillers.
What Is a Scroll Chiller?
A scroll chiller uses an orbiting scroll compressor — two interleaved spiral-shaped scrolls, one fixed and one orbiting — to compress refrigerant. As the orbiting scroll moves, the space between the two spirals shrinks, compressing the gas smoothly and continuously toward the center. Jaideo Automation supplies scroll chiller ranges including the York YCAL and York YCWL series.
How Does a Scroll Compressor Work?
Unlike screw or centrifugal compressors, a scroll compressor has very few moving parts — just the two scrolls and the motor driving them. That simplicity means:
- Fewer parts to wear or fail
- Lower vibration and noise than reciprocating compressors
- Good part-load performance, especially with multiple scroll compressors staged together
- Compact footprint relative to capacity
Scroll vs Screw vs Centrifugal Chillers
| Scroll | Screw | Centrifugal | |
|---|---|---|---|
| Typical capacity | Under ~100 TR | ~100–500 TR | 150 TR to 1000+ TR |
| Moving parts | Fewest | Moderate | Most (at high speed) |
| Best for | Small–mid commercial, modular plants | Mid-size commercial/industrial, variable loads | Large buildings, campuses, district cooling |
See the full Screw Chillers guide and Centrifugal Chiller guide for the other two.
Applications
Scroll chillers are commonly specified for:
- Small and mid-size office buildings
- Retail stores and showrooms
- Modular chiller plants, where multiple scroll units are staged for redundancy and part-load efficiency
- Restaurants, clinics, and boutique hospitality projects
Air-Cooled vs Water-Cooled Scroll Chillers
Scroll chillers are available in both air-cooled and water-cooled configurations. Air-cooled scroll chillers skip the cooling tower entirely, which keeps installation simple — a common choice where roof or yard space is available but water access is limited. See our Air-Cooled vs Water-Cooled Chiller guide for the full trade-off.
Where Scroll Chillers Fit in Your Selection
For a full walkthrough of how scroll chillers compare against every other type when planning a project, see our Types of Chillers guide and Chiller Selection Guide; to size the plant first, use the Chiller Tonnage & Capacity Sizing Guide. More scroll options are on the product pages for Air Cooled Scroll Chillers, York YLAA and the YMAE Inverter Scroll Modular Heat Pump Chiller. Scroll chillers typically feed fan coil units and air handlers such as the Standard Air Handling Unit, and for how speed control cuts energy at part load, see Variable Speed Drive Chillers.
Frequently Asked Questions
What is a scroll chiller?
A scroll chiller uses an orbiting scroll compressor with two interleaved spiral elements to compress refrigerant, producing chilled water for HVAC systems typically under 100 TR of capacity.
What is the difference between a scroll chiller and a screw chiller?
Scroll chillers suit smaller capacities (typically under 100 TR) with fewer moving parts and lower vibration, while screw chillers scale to larger medium-capacity loads with strong part-load efficiency.
Are scroll chillers available air-cooled and water-cooled?
Yes. Scroll chillers are available in both air-cooled and water-cooled configurations, with the choice depending on site water access and efficiency requirements.