| Air-Cooled Screw Chiller | Rejects heat directly to outdoor air through condenser coils and fans. | Facilities that need a central chilled-water plant without a cooling tower. | Avoids cooling-tower water treatment and simplifies plant equipment. | Performance can decline in high outdoor temperatures; fan noise and outdoor space may be factors. | Cooling capacity at design conditions, sound levels, part-load efficiency, and available redundancy. |
| Water-Cooled Screw Chiller | Transfers heat to condenser water, typically served by a cooling tower. | Medium-to-large facilities with an established condenser-water system. | Can provide efficient operation when the tower and water system are properly designed and maintained. | Requires cooling-tower equipment, water treatment, and ongoing maintenance. | Full- and part-load efficiency, tower compatibility, water use, and maintenance requirements. |
| Centrifugal Chiller | Usually water-cooled; uses a centrifugal compressor to move refrigerant. | Large campuses or production facilities with substantial, relatively continuous cooling loads. | Well suited to high-capacity central plants and can be efficient near its intended operating range. | Plant design, minimum-load behavior, and equipment-room requirements need careful evaluation. | Capacity range, efficiency across the load profile, turndown, and standby-unit strategy. |
| Magnetic-Bearing Centrifugal Chiller | Typically water-cooled; uses magnetic bearings in a centrifugal compressor. | Facilities seeking efficient operation over varying loads and reduced compressor bearing contact. | Oil-free compressor designs can avoid oil management in the refrigerant circuit. | Controls, service capability, and operating limits should be reviewed for the specific application. | Part-load performance, operating envelope, service support, and integration with plant controls. |
| Modular Scroll Chiller Plant | Available in air-cooled or water-cooled arrangements, depending on the equipment design. | Smaller facilities or sites that expect staged growth in cooling demand. | Multiple modules can stage capacity and allow one unit to be serviced while others operate. | Many modules may require more piping, connections, and coordinated controls than a single unit. | Module staging, minimum stable capacity, service isolation, and expansion flexibility. |
| Oil-Free Centrifugal Chiller | Heat rejection depends on the selected air-cooled or water-cooled design. | Process and HVAC loads where oil-free compressor operation is a design preference. | Eliminates compressor lubricating oil from the refrigerant circuit in oil-free designs. | “Oil-free” does not remove the need for routine inspection, refrigerant management, or system maintenance. | Efficiency at actual operating conditions, capacity control, refrigerant, and service arrangements. |
| Low-Temperature Glycol Chiller | Heat is rejected through an air-cooled or water-cooled condenser; the secondary loop uses glycol solution. | Processes or equipment requiring fluid temperatures below the normal chilled-water range, or added freeze protection. | Glycol can reduce freeze risk in exposed or low-temperature circuits. | Glycol concentration affects fluid heat transfer and pumping requirements; verify compatibility and setpoints. | Required leaving-fluid temperature, glycol type and concentration, pump sizing, and heat-exchanger duty. |
| N+1 Redundant Chiller Plant | Uses one more chiller than the number required to meet the design load; heat rejection follows the selected chiller type. | Cleanroom operations where cooling continuity is important during equipment failure or maintenance. | Provides standby capacity when configured and controlled so remaining units can carry the required load. | Redundancy adds capital cost and does not by itself protect against shared failures in pumps, power, or controls. | Capacity after the largest-unit failure, electrical and hydraulic independence, and maintenance procedures. |
| Chiller Plant with Waterside Economizer | Uses a heat exchanger and cool outdoor conditions to reduce or bypass compressor operation when conditions permit. | Sites with suitable seasonal conditions and chilled-water temperatures that allow economizer operation. | Can reduce compressor energy use during eligible operating hours. | Benefits depend on climate, water temperatures, heat-exchanger approach, and system controls. | Annual eligible hours, economizer changeover logic, added pressure drop, and water-side design. |
| Central Chiller with Dedicated Secondary Process Loop | A central chiller cools a primary loop; a heat exchanger separates it from a dedicated cleanroom or process loop. | Facilities that need hydraulic separation or distinct fluid conditions for sensitive process equipment. | Allows separate loop controls and can limit direct interaction between primary-plant fluid and process equipment. | The heat exchanger creates a temperature approach, so primary chilled water may need to be colder than the secondary supply. | Heat-exchanger sizing, secondary-loop temperature stability, pump arrangement, and contamination-control requirements. |