Energetic Behaviour of a Solar Thermal System Producing Domestic Hot Water and Preheating the Ventilation Air
Abstract
As a result of the evolution of the thermal regulation in Europe, buildings are better isolated and more airtight, thereby reducing their heating needs. Efficient systems from the energetic point of view, using preferably renewable sources, must cover the new distribution of needs. Indeed, domestic hot water (DHW) becomes a more important load than space heating in residential buildings and air renewal, necessary to guarantee indoor air quality, represents a significant thermal loss. In this context, solar thermal systems are appropriate for supplying a significant part of the heat demand in energy efficient housing. Thus, this paper focuses on a solar thermal system producing DHW and preheating the ventilation air. A co-simulation between Dymola (Modelica language) and EnergyPlus forecasts the energy performance of the system in a low-energy individual house for different French cities. The results show an improved collector efficiency as well as a higher solar productivity in comparison to a classical solar domestic hot water system in all the studied cases. Although energy savings are achieved for the majority of the studied climates, a different control strategy may be interesting in order to improve the distribution of the collected solar energy. To this end, a parametric analysis provides some clues for increasing the energy performance of the innovative system when modifying the design and control parameters.