The needs of the digital revolution and the knowledge-based economy impose a transformation of traditional education to improve technical and scientific knowledge and include alternative abilities. This work presents a service-learning initiative with multiple goals: to improve scientific, technical, engineering, and mathematic (STEM) knowledge at school, to enhance students' engagement, and to make people aware of the repercussions of poor indoor air quality. The initiative involves four actors: the administration which steers the initiative, students who are the receivers of the knowledge, teachers as facilitators of the activity and research centers as expert references. Within this service-learning initiative, a real-life project has been proposed, focusing on measuring carbon dioxide (CO[subscript 2]) levels in classrooms and correlating them with indoor airborne infection transmission. Reference experts have developed two systems provided to teachers and students for project implementation. The project involves an engineering step where students set up the systems, and a scientific step where students hypothesize, develop experiments, analyse data, and communicate results gaining experience with the scientific method. Through the combined efforts and appropriate allocation of responsibilities, this experience has yielded excellent results in STEM knowledge transmission and has proven effective in fostering student commitment to their learning process.