Stakeholders have utilized heating, ventilation, and air conditioning (HVAC) to provide thermal comfort. A team led by Prof. Stefan Seelecke developed the novel air conditioning technology. The technology cools the air through the use of muscles. The muscles consists of nickel-titanium. Susanne Kirsch and Felix Welsch helped in the development of this system while doing a doctoral research project. Prof. Stefan Seelecke and his team from Saarland University have been advancing this cooling system. The cooling system saves energy and conserves the environment.

The cooling system uses shape-memory constituents called artificial muscles. The muscles transfer heat by unloading and loading the nickel-titanium wires. Seelecke and his team aim to use the cooling system in electric vehicles. The team has been presenting their developments at Hannover Messe.

Over time we’ve seen developments in the cooling systems. That is, from simple home fridges to complex systems. People have embraced all these cooling systems. But some of these systems promote global warming and environmental degradation. Thus, society needs energy-efficient systems to reduce global degradation. Some cooling systems consume a lot of electricity in their functioning. Thus, they emit refrigerant gases and carbon footprint. Seelecke and his team have developed a cooling system that favors the environment.

The process used by Saarland University does not use refrigerants that can harm the climate. Their cooling system is more than 15 times more efficient than cooling systems based on harmful refrigerants. Both the United States Department of Energy and the EU Commission have approved the cooling system. Both stakeholders see the system as the best substitute for vapor-compression refrigeration systems.

The nickel-titanium wires in the system have special properties. The properties enable them to return to their original state after stretching. Hence, the muscles in the system tense and relax with ease. The nickel-titanium alloy consists of atoms that form crystal lattice structures.

When the wires are subject to any force the atom layers move relative to one another hence creating strain within the wire. The changes in the crystal structure cause transitions called phase transitions. The phase transitions cause the nickel-titanium wires to absorb and release heat. The muscles release heat to their surroundings when loaded in their super elastic state. They also absorb heat from the surroundings when unloaded.

The team has also developed a more complex cooling system called the Saarbrucken system. The circuit in this system has a patent-pending cam drive. The drive rotates thus, stretching and relaxing 200 nitinol wires. Through these movements, heat transfer occurs in an effective manner. The system has two chambers through which blown air passes to get into the system. In one chamber the blown air get heated and cooled in the other chamber. Hence, the cooling system cools and heats.

To develop HVAC technologies Intelligent Systems Lab has established mateligent GmbH Company.