| Air-Cooled Screw Chiller | Twin-screw compressors circulate refrigerant through an evaporator and air-cooled condenser. The refrigerant absorbs heat from chilled water and rejects it to outdoor air. | Approximately 100–1,500 kW | Approximately 5–7°C | Condenser fans and outdoor air | No cooling tower or condenser-water pump; relatively simple installation; suitable for locations with limited water availability. | Higher energy use during hot weather; outdoor noise; performance varies with ambient temperature. | Commercial buildings, process cooling, warehouses, and medium-sized industrial facilities. |
| Water-Cooled Screw Chiller | A screw compressor raises refrigerant pressure and temperature. Heat is transferred to condenser water, which then rejects heat through a cooling tower. | Approximately 300–2,000 kW | Approximately 5–7°C | Condenser water and cooling tower | Good part-load efficiency; stable performance in warm climates; compact refrigeration package for medium-to-large loads. | Requires cooling tower, water treatment, pumps, and regular maintenance; consumes water. | Industrial plants, hospitals, district cooling systems, and large commercial buildings. |
| Centrifugal Chiller | A high-speed impeller adds velocity to the refrigerant vapor, and a diffuser converts that velocity into pressure before condensation and expansion. | Approximately 1,000–10,000+ kW | Approximately 5–7°C | Usually condenser water and cooling tower | High efficiency at large and relatively steady loads; low vibration; excellent capacity modulation with variable-speed drives. | Higher initial cost; less suitable for very small loads; surge control and specialist service may be required. | Large office complexes, airports, universities, data centers, and district cooling networks. |
| Scroll Chiller | Two interleaved scrolls compress refrigerant vapor continuously. Multiple small compressors can be staged to match changing cooling demand. | Approximately 10–350 kW | Approximately 5–7°C | Air-cooled or water-cooled, depending on configuration | Quiet operation; compact footprint; low vibration; good redundancy when several compressors are installed. | Limited capacity per compressor; not normally preferred for very large continuous loads. | Small commercial buildings, laboratories, food-processing equipment, and light industrial systems. |
| Reciprocating Chiller | Pistons compress refrigerant vapor inside cylinders. Suction and discharge valves control the refrigerant flow during each piston cycle. | Approximately 10–500 kW | Approximately 2–7°C | Air-cooled or water-cooled | Works across a broad operating range; suitable for smaller systems and some low-temperature applications. | More vibration and mechanical wear than scroll compressors; may require more maintenance. | Specialized process cooling, small cold-storage systems, and legacy refrigeration installations. |
| Absorption Chiller | Heat, rather than a mechanical compressor, drives refrigerant separation and circulation. Common working pairs include water–lithium bromide and ammonia–water. | Approximately 100–5,000 kW | Approximately 5–7°C for comfort cooling | Cooling tower is commonly required | Can use waste heat, steam, or direct-fired heat; reduces electrical demand where suitable heat is available. | Lower coefficient of performance than electric chillers; larger footprint; requires heat-source and water-treatment management. | Combined heat and power plants, industrial facilities, district energy systems, and sites with abundant waste heat. |