Korean scientists unveil 10 kW chemical adsorption heat pump prototype

Researchers from the Korea Institute of Machinery and Materials (KIMM) have developed a prototype of a chemical adsorption heat pump for cooling applications in commercial buildings, factories and data centers.

A chemical adsorption heat pump is a thermally driven system that uses the reversible attraction between a solid adsorbent and a refrigerant vapor to transfer heat and produce heating or cooling, with little mechanical compression. Instead of using an electrically powered compressor like a conventional heat pump, it supplies heat—such as industrial waste heat—to the adsorbent, causing the refrigerant previously held on its surface to be released.

The refrigerant is then condensed, rejecting heat before evaporating at low pressure and absorbing heat from the space or process being cooled. During the adsorption phase, the vapor is drawn back onto the solid adsorbent, allowing the cycle to repeat. Because heat is the main energy input, chemical adsorption heat pumps can convert otherwise unused low-temperature waste heat into useful cooling or heating while requiring relatively little electricity.

The whole system is primarily driven by waste heat, with electricity required only for auxiliary equipment such as pumps, valves, and controls.

According to its creators, the 10 kW system can provide cooling using waste heat at approximately 40 C, significantly below the 70 C-plus heat sources typically required by conventional adsorption cooling systems.

They said the core of the system is adsorption bed, which holds and releases the refrigerant and transfers heat efficiently between the adsorbent and the external heat source. It reportedly achieved a specific cooling power (SCP) of 346.5 W/kg, which the team said is more than twice the performance of comparable international technologies and represents a “world-leading level of performance.”

“The developed system incorporates an electrochemical compressor with no mechanical moving parts,” the researchers further explained. “Compared with conventional mechanical compressors, it reduces energy consumption while generating virtually no noise or vibration, making it well suited to hospitals, schools, residential areas, and other noise-sensitive environments.”

“In addition, the system uses ammonia, a natural refrigerant, enabling compliance with international refrigerant regulations while providing an environmentally friendly heating and cooling solution,” they emphasized.