Experimental Performance Evaluation of a Solar Air Heater Using Recycled Aluminum Soda Cans Absorbers Under Maiduguri Climatic Conditions

Abstract

This study experimentally investigated the performance of a solar air heater (SAH) constructed using recycled aluminium beverage soda cans as absorber tubes under Maiduguri harmattan climatic season. The research addressed the growing need for low-cost, environmentally sustainable heating systems for applications such as space heating and crop drying in regions with abundant solar radiation. The system was designed as a single-pass solar air collector with dimensions 1.09 m × 0.835 m × 0.15 m and collector area of 0.91 m². The absorber consisted of 96 aluminium soda cans arranged in a 12 × 8 matrix and coated with black paint to improve solar absorptivity. Experiments were conducted in active mode using a 12 V DC fan with air mass flow rate of 0.00113 kg/s and in passive mode airflow movement which occurred naturally through buoyancy-driven convection. The collector was tested at tilt angles of 25°, 30°, 45°, 60°, and 180°. Performance parameters included outlet air temperature, temperature rise, useful heat gain, and collector efficiency. Results indicated that the active system achieved a maximum thermal efficiency of 14 % with useful heat gain of approximately 90W at 45o tilt angle. Also, the passive mode achieved 16% efficiency with optimum performance at 45° tilt angle with maximum useful heat gain of 130.2W. The results confirmed that discarded aluminium cans can be effectively used as low-cost absorber materials for solar air heaters in solar-rich regions, such as Maiduguri.