This paper discusses a new test platform for evaluating the performance of solar thermal collectors that was recently designed and constructed on the roof of the Applied Energy Laboratory at Purdue University, located at 40.4 °N and 86.9 °W. The test platform is mainly used for teaching undergraduate students about applications of thermodynamics and renewable energy, but it can also be used for comparative evaluations of solar thermal collector designs according to an established test standard. The entire system is monitored and controlled by a web-based Building Automation System that automatically tracks and trends both weather data and the performance of individual solar collectors. The online data is particularly helpful for undergraduate education because large numbers of students, including international partners, can access real-time data to learn about solar energy applications. The weather at this location varies significantly by season, which has a substantial impact on the performance of the solar thermal collectors. ASHRAE designates this location as climate zone that experiences both hot, humid summers and cold, dry winters. The solar intensity also varies by season, with longer and more sunny days during the summer and shorter and more cloudy days during the winter. Not surprisingly, evaluations of solar collector performance vary seasonally too. Solar collector efficiency, the ratio of thermal energy collected to the solar energy available, varies from 10% to 80%. Solar energy factor, the ratio of thermal energy collected to the source energy (electricity) to circulate the fluid, varies from 10 to 150. Both performance terms (efficiency and energy factor) are needed to get a complete picture of solar collector performance.
Solar thermal energy, building automation, undergraduate education
Date of this Version
Hutzel, Bill; Horton, W. Travis; and Zimpfer, Mark, "Remotely Accessible Laboratory for Teaching and Research on Solar Thermal Collectors" (2020). School of Mechanical Engineering Faculty Publications. Paper 29.