LAUSR

Abstract This work studies the relative influence of the constructive characteristics of thermosiphon factory made solar heating systems of components such as absorber type, collector area, thermal insulation of both collector(s) and tank, tank volume and volume/area ratio, on the annual energy production, the annual efficiency and the solar fraction. The research has been conducted on 28 systems available in the market, tested according to Standard ISO 9459-5:2007 and simulated fo different European reference locations (Athens, Davos, Wurzburg and Stockholm) according to Standard EN 12976-2:2019. The results show that reduced volume has a marked influence on the energetic and efficiency behaviour of these systems. In particular, for reduced volume values greater than 0.8, the constructive characteristics have high influence on systems behaviour. On the contrary, for reduced volume values lower than 0.8, all tested systems have a similar behaviour at the same location. The results found in this study allow optimizing the design of TSWHS, as well as selecting a specific system according to the location and a daily load volume.