STULZ Tech Brief: Chiller Units
News | 01.05.2025
This month, we’re putting the spotlight on STULZ Chiller Units — high-performance cooling systems built for maximum efficiency in data centers, laboratories, and industrial environments. Designed for precision, scalability, and low energy consumption, STULZ chillers are your reliable partner in meeting today’s most demanding thermal challenges.
Stulz Chiller Units are highly reliable cooling systems designed to deliver maximum efficiency and stable performance in mission-critical IT and industrial environments. Equipped with advanced technologies, Stulz chillers provide precise temperature control, energy efficiency, and long-term durability, meeting the highest cooling demands of data centers, telecommunications, and other high-load infrastructures.

CyberCool WaterTec - Smart, Sustainable, and Highly Efficient Water-Cooled Chiller
CyberCool WaterTec Designed with a forward-thinking approach, the CyberCool WaterTec offers compact, maintenance-friendly construction combined with Turbocor compressor technology optimized for partial loads. This water-cooled chiller uses the environmentally conscious refrigerant R1234ze, significantly reducing environmental impact without compromising performance.
Key features of the CyberCool WaterTec:
- Optional Free Cooling via the CyberCool Free Cooling Booster
- Minimal refrigerant use with eco-friendly R1234ze
- Seamless integration and maintenance in chilled water systems
- 5 models across 4 sizes
- Turbocor compressors optimized for part-load efficiency
- Technical Specs. Cooling capacity: 350 – 1,510 kW

Explorer WSW – Flexible, Water-Cooled Chiller for Mission-Critical Systems
Explorer WSW is a versatile water-cooled chiller with electronic expansion valve, smart control, and variable power regulation. Paired with the CyberCool Free Cooling Booster and dry cooler, it offers high energy savings in temperate and cold climates.
Key features of the Explorer WSW:
- Free Cooling enabled with CyberCool Free Cooling Booster and dry cooler
- Eco-friendly R513A refrigerant with low GWP (573)
- High performance with minimal footprint
- Robust components with easy access for maintenance
- Available in single or dual circuit configurations
- 16 size options for different capacities
- Cooling capacity: 230 – 1,530 kW
- Refrigerant: R513A (GWP: 573)

CyberCool Indoor – Compact Chiller with Integrated Free Cooling for Indoor Use
CyberCool Indoor delivers efficient, high-performance chilled water cooling for indoor environments such as IT spaces, medical equipment, and critical facilities. Its compact, modern design allows for easy installation inside buildings and seamless integration into existing systems. The system is available in configurations with or without EC compressors, meeting a wide range of project needs.
Key features of the CyberCool Indoor:
- Integrated Free Cooling for reduced operating costs (GE/GES systems)
- Customized adaptations for unique cooling requirements
- Installable directly near the heat source
- Available with and without EC compressors
- Three system variants available
- Technical Specs. Cooling capacity: 20 – 100 kW

Explorer WPA – Compact and Flexible Air-Cooled Chiller for Critical Applications
Explorer WPA is a versatile air-cooled chiller system that combines high efficiency, reliability, and adaptability. Designed with project-specific flexibility in mind, this system features microchannel condensers for improved heat exchange and minimal refrigerant use, along with dual refrigerant circuits for increased redundancy. Its compact, lightweight construction allows for easy integration in a wide variety of setups.
Key features of the Explorer WPA:
- Microchannel condensers for high performance and low refrigerant use
- Two independent refrigerant circuits for high availability
- Compact design enables easy installation in diverse environments
- Transportable globally via ISO container
- Outdoor installation from -40°C to +45°C
- Cold water outlet range: -7°C to +25°C
- 138 models across 10 sizes
- Cooling capacity: 80 – 1,200 kW

CyberCool Free Cooling Booster – Maximize Efficiency with Retrofitted Free Cooling
CyberCool Free Cooling Booster is an innovative solution that allows traditional water-cooled chiller systems to benefit from Free Cooling, even in installations where it’s not typically available. With support for precise Mixed mode operation, this plug-and-play system enables year-round energy savings by leveraging low ambient temperatures at the site.
Key features of the CyberCool Free Cooling Booster:
- Substantial energy savings with Free Cooling and Mixed mode
- Quick setup with minimal commissioning thanks to plug-and-play design
- High reliability via redundant components and robust engineering
- Optional glycol in consumer circuit
- Maintenance-friendly construction
- Variable speed, energy-efficient pumps
- Cooling capacity: 270 – 1,800 kW

CyberCool Explorer WS – High-Efficiency Air-Cooled Screw Chillers with Free Cooling
CyberCool Explorer WS is purpose-built to meet the demanding cooling needs of data centers, offering a wide capacity range of 280 to 1,860 kW. Designed for high-temperature operation, these units enable integrated Free Cooling for most of the year, significantly reducing energy consumption and operational costs.
Key features of the CyberCool Explorer WS:
- Energy-saving Free Cooling for year-round performance
- Compliant with ErP2021 - SEPR HT (EU) 2016/2281 standards
- Available with microchannel or finned tube condensers
- Outdoor-ready: corrosion- and weather-resistant design
- Screw compressors with stepless (WSA) or frequency-controlled (WSI) operation
- Cooling capacity: 280 – 1,860 kW
- Refrigerants: R1234ze (GWP: 7), R513A (GWP: 573)