Solar Air Collectors in Cold Climates to Achieve Energy Efficiency in Residential Buildings

Solar energy is becoming a cardinal element for the decarbonization of our society and pushing toward new levels of energy conservation. In current practice, great attention has been paid to photovoltaic systems that are in a phase of great expansion. Nevertheless, other technologies such as solar air collectors can be a promising solution to help in the process of achieving zero-energy buildings, especially considering more advanced solutions. In this study, the use of a concentrating solar air collector to provide heating and domestic hot water in a residential building in cold climates is explored. The innovative solution employs a rock bed storage to store thermal energy for heating applications and an air-to-water heat exchanger to exploit the surplus energy, especially in the summer period, and convert it into domestic hot water. Simulations are performed with transient simulation software TRNSYS considering a two-story building located in Krakow (Poland). The control system considers different variables and parameters for the activation of the different components of the plant to optimize the plant operation and maximize energy efficiency. Results indicate how the proposed system can considerably contribute to the heating of the building and almost completely satisfy the energy need for domestic hot water.