Researchers in South Korea have developed a new type of heat pump that can turn low-temperature waste heat from factories and data centers into cooling.
The breakthrough could reduce electricity use, improve energy efficiency and help lower greenhouse gas emissions by making better use of heat that would otherwise go to waste.
The new system was developed by a team led by Dr. Young Kim at the Korea Institute of Machinery and Materials (KIMM), working with researchers from Chung-Ang University.
Together, they created a next-generation chemical adsorption heat pump that operates using waste heat at temperatures of only about 40°C (104°F), much lower than what existing systems require.
Heat pumps are widely used for heating and cooling buildings. Most conventional air conditioners work by using electricity to power a mechanical compressor that squeezes a refrigerant, allowing it to absorb and release heat. This process is effective but consumes a significant amount of electricity.
The newly developed system works differently. Instead of relying mainly on electricity, it uses waste heat that is already being produced by industrial facilities and data centers.
These buildings generate large amounts of low-temperature heat during normal operations, but much of it is simply released into the environment without being used.
Previous adsorption cooling systems generally needed waste heat above 70°C (158°F) to operate efficiently. That meant many potential sources of waste heat were simply too cool to be useful.
The new technology overcomes this limitation by successfully producing cooling using waste heat at only 40°C. This greatly expands the number of places where waste heat can be recycled into useful cooling.
One of the biggest improvements comes from redesigning the adsorption bed, which is the heart of the heat pump. This component temporarily stores and releases refrigerant during the cooling cycle. The researchers achieved a specific cooling power of 346.5 watts per kilogram, more than twice the performance reported for similar technologies overseas. According to the team, this represents a world-leading level of performance.
Another key innovation is the use of an electrochemical compressor instead of a traditional mechanical compressor. Because it has no moving mechanical parts, the compressor produces almost no noise or vibration while also using less energy.
This quiet operation could make the technology especially attractive for places where noise is a concern, including hospitals, schools, office buildings and residential neighborhoods.
The research team also worked on developing a larger ammonia-based electrochemical compressor, bringing the technology closer to commercial use. Ammonia is a natural refrigerant that has little impact on global warming compared with many synthetic refrigerants currently used in air conditioning systems. Using ammonia also helps the system meet increasingly strict international environmental regulations.
The researchers believe the technology could eventually be used in data centers, manufacturing plants and commercial buildings, where large amounts of waste heat are available every day. Instead of throwing that energy away, facilities could recycle it to provide cooling, reducing both electricity consumption and operating costs.
The team has already built and is testing a 10-kilowatt prototype of the new heat pump. If these demonstration trials continue to be successful, the researchers plan to carry out larger field tests and continue improving the system, bringing this energy-saving technology one step closer to real-world use.
