An approach to investigate the interface between built environment and thermosyphon solar water heating system

Abstract Several studies have already highlighted the benefits associated with the use of Solar Water Heating Systems (SWHS). Although this technology is already consolidated, there is a lack of studies regarding the impacts of its interaction with the user and the built environment. Thus, this work presents a multiparametric sensitivity analysis applied to identify and quantify the constructive and operational parameters that sensitize the SWHS performance indicators. This study was carried out at the city of Sao Paulo, Brazil, using computer simulation in the EnergyPlus software. The model was validated presenting an average error of 7.5%. The collector orientation proved to be the most critical constructive limitation for the SWHS performance. The divergence in the electric power consumption due to distinct orientations reached 60%. Lower flat plate collector inclination (i=20°) favors lower energy consumption during winter for some critical orientations. The constructive parameters Vst/Acol ratio and tank volume affect significatively the performance of indicators providing saving of even 284 kWh/year and increasing the tank temperature up to 15°C. Changes on showering time may provide an increase of even 170 kWh/year in the useful energy gain. The results indicate that adequate adjustments in the parameters settings compensate or minimize the effects of constructive limitations.