Energy, Exergy, and Sustainability Assessment of Modified Solar Air Heater Configurations

Abstract

This study is an experimental study that compares the thermo-hydraulic, energetic and sustainability efficiency of finned and unfinned solar air heaters which work under the same climatic conditions. Both configurations were also experimented concurrently during a typical sun day (09:00-16:00) encountering four mass flow rates of 0.0383 to 0.06 kg/s -1. The finned heater reached its highest temperature gain of 10 ⁰C, which is a 67-percentage point higher compared to the unfinned system, and reached a thermal efficiency of 56 percent. On the other hand, the unfinned design had a greater exergy efficiency (0.99>5%) and a sustainability index of 5.8 at high flow rates. Together, the findings suggest finned designs have a better performance at lower flow rates, and unfinned systems can be used to implement high-output, applications focused on sustainability.