Simulation and experimentation of an integrated collector storage solar water heater designed for integration into building facade

Highlights: • A novel collector-storage solar water heater integrated in building facade. • Device reflector made of small rectangular and pivoting mirrors. • Device produces warm water and ensures ventilation of the dwelling when not used. • A thermal model developed and validate with experimental results. • Effective daily and night operation of the device. -- Abstract: This paper relates to design, construction and experimentation of an innovative Integrated Collector Storage Solar Water heater (ICSSWH) equipped with a linear parabolic reflector. The device is designed for integration into a building facade in Algerian Sahara to meet hot water needs of households in winter. Its reflector is made of small rectangular and pivoting mirrors assembled on a wooden framework. During summer period the solar water heater is not used; when pivoting the small mirrors of the reflector towards the horizontal position, we can use the device to ventilate the interior of the building according to the principle of the venetian blind. The numerical model of the device was developed and a prototype was constructed and experimentally tested. Experimental tests demonstrated that the device is effective only during winter period. Its mean daily efficiency varies between 36.4 and 51.6% and its thermal losses coefficient during night-time varies between 2.17 and 3.12 W K^-1. Under a clear sky with an initial temperature of 22 °C, water temperature increases to reach a maximum at 49 °C. The numerical model was validated by comparison with experimental results and then used to investigate the influence of some design parameters.