Passive solar house prototype design with a new bio-based material for a semi-arid climate

In this study, a passive solar house prototype was built using Trombe wall and was tested in the semi-arid region of Batna, in eastern Algeria. Traditional local materials (stone and adobe) were used for the construction of the thermal storage wall. A new local bio-based material made from date palm trunks was used for the insulation of the passive house prototype. For a better understanding of passive house heating and for a comparative study, a numerical simulation, using Fluent, was carried out. The aim of this study was to supply recommendations for improving the passive systems and to participate to the energy consumption control in the building sector. The results show that the experimental and numerical simulation results are in good agreement. The optimal orientation of the solar passive house has been determined, which is at 160° southeast. The use of local and bio-based materials has proven its effectiveness in the construction of the passive house. The thermal behavior of date palm wood has been found to be close to those of insulation materials commonly used in buildings. That means it has the same thermal insulation ability (thermal conductivity). On the other hand, the results show that the thermal efficiency of the passive solar heating system, with an adobe wall is significantly higher (50%) than that with a stone wall (30.7%).

Arduino-based night return mechanism for passive solar trackers

<p>Solar trackers are support platforms that keep photovoltaic panels facing the sun by following the sun from dusk to dawn. There exist active solar trackers that make use of motors and gears to orientate the photovoltaic panels towards the sun; and passive solar trackers that operate through the differential heating of the fluid in the tracking rack to follow the sun. Passive solar trackers suffer from the lack of a night return mechanism and a slow wake-up response in the mornings due to the limitations on the surface inclination angle of the rack. This paper seeks to address these issues by proposing an Arduino-based night return mechanism for passive solar trackers. An energy-saving heating element such as the ultra heating fabric manufactured by WireKinetics Co. is installed on the west-side canister of the tracker. Before dawn, the fabric is automatically heated and this will force the refrigerant in the west-side canister to vaporize and cool in the east- side canister, forcing the tracker to return and face eastward before sunrise. The night return mechanism is designed and simulated using Proteus profesional. Simulation results show that this system can significantly optimize the function of passive solar trackers.</p>