The application of solar heating and cooling technologies is one of the most important strategies aiming at the decrease of fossil fuel and electricity consumption in buildings, which is one of the main priorities of the EU environmental policy. The advantages of using solar radiation for space heating and cooling and for the hot water production are environmental, since it can lead to fewer CO2 and pollutants emissions, as well as economic, since they are associated with lower operation costs in buildings.
The present proposal focuses on the development of advanced, high efficiency technologies and their integration into a simple and flexible solar heating and cooling system. The components of this system consist of:
1) Enhanced, high efficiency, high temperature flat plate solar collectors. The enhancement of the collector efficiency will be achieved by interventions including the selection of proper insulation thickness, the use of transparent insulation materials, the application of double glass combining anti-reflective layering and the construction of new aluminum profiles and angular connections.
2) Heating and cooling system based on the application of the vapor compression cycle (VCC) and the ejector cooling cycle (ECC). The solar heating and cooling system utilize the available solar radiation for covering the demands. Solar cooling is achieved via the application of an ejector cooling cycle (ECC). In the case that the solar energy input is insufficient, a conventional heat pump is used (VCC).
3) Roof heating/cooling elements with low temperature radiation. The advantages of the use of roof heating elements include comfort, energetic efficiency, low operation costs, decreased space requirements, uniform temperature distribution, quiet operation, sound suppression and hygiene.
4) Nanofluids of optimized thermal performance in the heating/cooling circuit. Within the project, research will be carried out on the optimization of the size of nanoparticles for the production of high thermal performance nanofluids Ag and CuO.
Τhe 4 components will be studied theoretically, while also prototypes will be designed and developed considering a base case application scenario in specified buildings. Beyond the individual and independent technical evaluation of each technological component, an integrated solar heating and cooling system combining them will be designed and manufactured. The pilot unit will be experimentally investigated, and its performance will be assessed for various operation conditions, which will be a fundamental step towards its commercialization.