In residential and commercial buildings, Heating, Ventilation, and Air Conditioning (HVAC) systems constitute about 35% of the total energy consumption. Although today, heating is the most energy demanding need, there is an increasing demand for cooling which is expected to increase even further in the years to come due to climate changes. To decrease the overall energy demand, it is vital to look for new and innovative technologies for increasing the efficiency of currently applied state-of-the-art HVAC systems.To efficiently tackle the need for less energy demanding HVAC systems for both residential buildings and commercial facilities, the overall focus of EnE-HVAC focus will be on the energy efficiencies heat transfer addressing on both the air side- and the refrigerant side of the systems. It will also, importantly, tackle the energy transportation within the system to ensure maximum efficiency. This will require very high performance characteristics of the refrigeration agents in use. To ensure a significant impact on global warming, there will be a focus on developing the use of coolants with no HFC and CFC content.The specific aim of EnE-HVAC is to facilitate a significant reduction of the total energy consumption in modern HVAC systems by combining a range of new nanotechnological solutions. There will be a clear focus on the optimization of the heat transfer of heat exchangers used in HVAC systems such as condensers and evaporators in HVAC systems, along with the design of systems and the development of new nanomaterial enhanced HFC and CFC free refrigerants. The culmination of the present project will be the demonstration of energy savings of up to 50% on the total energy consumed in the developed HVAC systems compared current to state-of-the-art commercial systems.The EnE-HVAC consortium comprises industry market leaders representing the value chain and leading research institute in surface technology and heating/cooling.