Dunham-Bush air-cooled chiller specifications vary by model, but common features include cooling capacities ranging from approximately 77 to 504 tons (271 to 1772 kW). These chillers often use R-134a or environmentally friendly refrigerants like R-513A. Key components include horizontal or vertical screw compressors, advanced microprocessor controllers like the DB-Director, high-efficiency microchannel condenser coils, and options for variable speed fans, twin compressors for redundancy, and high-ambient operation. 

Performance and capacity 

• Cooling Capacity: Varies by model, with ranges such as 77 to 191 tons (271 to 672 kW) for the AFHX Series or 93 to 249 tons (329 to 875 kW) for the ACHX-DVE and ACHX-D series.
• Refrigerant: Commonly uses R-134a or environmentally friendly options like HFO-R513A.
• Efficiency: Features high-efficiency components, including screw compressors and condenser coils, to lower energy consumption.
• High Ambient Options: Specific models like the ACHX-BH are designed for high-ambient temperature operation, with capacities up to 418 tons (1470 kW). 

Components and features 

• Compressors: Typically equipped with high-efficiency horizontal or vertical screw compressors. Many models feature twin compressors with independent circuits for redundancy and reliability.
• Condenser Coil: Often includes an all-aluminum microchannel condenser coil for improved heat transfer. An optional fin and tube condenser is also available.
• Condenser Fans: Some series, like the ACHX-DVE, use variable speed electronically commutated (EC) fans for improved part-load efficiency and low noise operation.
• Evaporator: The AFHX series uses flooded evaporators for higher capacity and efficiency. The AFVX-B-6SR series also features a flooded evaporator.
• Controller: Uses an advanced microprocessor controller, such as the Vision controller or DB-Director, which offers features like a back-lit display, easy access to parameters, and scrolling messages in English. 

Certifications and compliance 

• AHRI Certified: Many models are AHRI certified, ensuring they meet or exceed industry performance standards.
• ASHRAE Compliance: Units meet or exceed ASHRAE 90.1 standards for energy efficiency. 

Availability 

• Voltage: Available in various voltages, such as 460V/3Ph/60Hz and 575V/3Ph/60Hz for certain models.