Traditional office hours are typically poorly attended for a variety of reasons, including the limitations imposed by faculty office space constraints in terms of simultaneous student participation. Virtual office hours are an option for instructors to support their students through a virtual learning environment. Research suggests that virtual environments are beneficial to both learners and educators, offering more flexibility in the learning process. Further, participation in office hours provides a platform for student-instructor interaction, claimed in the growing body of research to improve student learning experiences overall. This paper describes the design and structure of virtual office hours offered in three undergraduate energy-related mechanical engineering courses (Thermodynamics, Fluid Mechanics, and Heat Transfer) before the COVID-19 pandemic. The student learning experience was analyzed through an assessment of student responses on anonymous end-of-course evaluations. Findings revealed that students appreciated the virtual office hours and felt that they were more accommodated than could have been in a traditional office hour setting. Findings suggested as well that students appreciated the virtual setting more as they progressed through a series of courses offering virtual office hours. Findings from our study can be helpful for a broader audience of researchers and educators in an educational environment that is increasingly online.