Absorption refrigeration is a cooling technology that uses heat energy instead of mechanical compression to drive the refrigeration cycle. A secondary fluid called an absorbent absorbs refrigerant vapor, which is then separated using heat. This technology powers approximately 10 percent of large commercial chillers and industrial cooling applications.
Operating Principles
The cycle uses lithium bromide or ammonia-water solutions. Heat input at 300-350 degrees Fahrenheit drives the separation process, eliminating the need for a compressor. The system generates cooling capacity of 100-2000 tons in commercial installations, with COPs between 0.6 and 1.2.
Advantages and Applications
Absorption systems excel where waste heat is available from generators, boilers, or solar collectors. They operate silently, require minimal vibration isolation, and utilize environmentally benign working fluids. Applications include district cooling systems, industrial process cooling, and facilities with combined heat and power systems.
Practical Considerations
Absorption chillers cost 40-60 percent more than vapor compression units but provide advantages in specific applications. Maintenance requires specialized technician training. These systems perform best in large-scale installations where thermal efficiency justifies higher capital costs.