The nanotechnology implementation is set to significantly increase the energy efficiency of heating and ventilation systems in the coming years. An EU funded project lead by the Danish Technological Institute is currently developing the technology that can help reduce this massive use of energy. Jacob Ask Hansen, Consultant at Danish Technological Institute, Denmark gives an account.
Although today, heating consumes the majority of the energy used for HVAC systems, there is also an increasing demand for cooling. This demand is expected to further increase in the coming years due to climate changes. Therefore, the ambitious goals of energy efficient HVAC can be realized only by tackling the efficiencies in all parts of the HVAC systems.
Energy efficient heat exchangers
To tackle the need for more energy efficient HVAC systems, the European Commission has granted a new project under the 7th Framework programme: EnE-HVAC – Energy efficient heat exchangers for HVAC applications. This project will achieve significant energy savings in future HVAC systems via new technologies that include nanotechnological coatings and surface treatments for improved heat transfer, new nano- and micro-materials for improved efficiency of the refrigerants and improved efficiency and heat transfer capabilities of coolants via new nanotechnological additives.
To minimize the energy consumption, it is vital to secure innovative solutions to significantly improve the current HVAC systems. The technologies have to be brought into play to achieve a far more efficient heat transfer in heat exchangers. This will significantly reduce the energy consumed in modern heat exchangers for cooling and ventilation.
The project deals with the heat exchanger efficiency on both the air and liquid side of heat exchangers such as condensers/evaporators and on heat recovery systems. It also addresses the heat transport system to ensure high efficiency throughout the HVAC system. To achieve these large energy savings, the project has put up requirements on the refrigerants used, to ensure least possible environmental effects. Thus, throughout the project there has been a significant focus on the use of “green” refrigerants avoiding HFC and CFC gasses. To decrease the overall energy demand, it is vital to increase the efficiency of currently applied HVAC systems. The new technologies are:
• Nanostructured coatings including Sol-gels and PVD coatings for increased heat transfer
• Nanotechnological coatings with anti-freezing properties to limit over icing of heat exchangers
• Nanofluids for the improvement of heat transport