Virtual Lab Modules for Undergraduate Courses Related to Building Energy Systems

Background: In the engineering education, hands-on laboratory experience is essential to enhancing students' practical skills such as conceptual understanding and problems solving skills. However, many students are not able to participate in practical activities (e.g., laboratory experiments) due to inaccessible or unavailable "brick and mortar" laboratories, especially when most universities have currently adopted the online instruction while students are sheltered at home due to the ongoing COVID-19 pandemic. Purpose: This paper presents a library of virtual laboratory modules expanded and enriched from our initial learning app through an Augmented Reality (AR) environment, where virtual objects (augmented components) are superimposed onto a real learning setting during online lecture instruction. Specifically, to facilitate students' gaining practical skills, a library of virtual objects were established for the main physical components or systems related to the undergraduate "Heating, Ventilating, and Air-conditioning (HVAC)" class to allow students to be immersed in an augmented learning reality representing the real physical world. Design: The library of virtual lab modules were established by: 1) including all the main HVAC components in an HVAC course; 2) refining these components' 3D models with learning materials (e.g., concept and evaluation); 3) improving the AR method to recognize each component's figures or pictures from any learning documents (e.g., printed lecture ppt notes and textbook, documents shown on computer or mobile screens, and a real HVAC setting); and 4) improving and/or reproducing the initial AR app using the OpenCV (replacing the original EasyAR software development kit) to sequence the learning materials upon request once an component is recognized. Results: This updated AR app with enriched virtual lab modules were tested and validated by the class lecturer and graduate students who have already taken this HVAC class before. Their feedback showed that the AR tool would allow them to learn at their own pace while the instructor is not face-to-face with them, and the results revealed that the tool enhanced their practical skills especially when they are sheltered at their homes without accessing a lab or field trip. This AR-based supplementary learning tool is ready for use in the HVAC class in this coming spring semester, and the app's effectiveness will be more comprehensively evaluated once students in the class adopt the tool. Conclusion: A well-designed AR learning app will effectively guide students to perform hands-on experiments related to the HVAC course and other STEM laboratory courses. The alternative pedagogy through AR technology also provides an efficient way to deliver practical experience online, especially when on-campus lab resources are limited or people are sheltered at home during natural disasters like the COVID-19 pandemic.