Performance Enhancement of Solar Air Heater by Integrating Innovative Absorber Design and Automatic Control Flow Rate

: Solar air heater is often used to warm air for residential heating and drying agricultural products. Developing a single-pass absorber of the solar air heater in the form of a wire mesh layer will significantly improve its performance under certain climatic conditions. To further increase the efficiency of the modified solar heater so that it can adapt to all climatic conditions, an automatic control system combined with a fan motor has been designed and integrated with the heater to provide it with suitable parameters such as temperature and airflow rate. To determine the effect of the automatic fan speed control affects solar air heater performance, an experimental investigation is presented in this paper. Under identical weather conditions, two tests were conducted for two consecutive days, one without and one with using automated fan speed control. The control system was programmed to regulate outlet air temperature with a range of 40-60 °C. Accordingly, the fan speed is automatically changed in response to temperature variations. Online monitoring and adjustment of temperature will increase air temperature stability and stop oscillations despite varying solar radiation levels during daytime hours. With greater thermal efficiency than conventional technique, this technology encourages more even airflow and improved heat transfer, raising surface temperatures in the heater duct. By using automated control, the thermal efficiency of the heater is increased by roughly 39.5 %.