STUDENT PAPER. This paper outlines the research design and methodological framework of a doctoral study aimed at enhancing indoor air quality (IAQ) in naturally ventilated (NV) Irish primary school classrooms. The study commenced with a systematic review of the literature, which provided critical insights into the relationships between carbon dioxide (CO2) levels, IAQ, ventilation adequacy, and their impacts on student health and academic performance. The review identified key knowledge gaps; no published research addresses IAQ or ventilation in Irish schools; there is limited understanding of how NV strategies affect thermal comfort, energy use, and the infiltration of outdoor pollutants; there is a lack of clear guidance on the applicability and efficacy of standard CO2 sampling methods in NV classrooms; and the effectiveness and practicality of ventilation enhancement measures in Irish settings remain underexplored. To address these gaps, the study adopts a pragmatic, mixed-methods, deductive approach across five phases, integrating CO2, nitrogen dioxide (NO2), and thermal comfort monitoring with teacher and school management surveys, as well as spatial CO2 mapping, to generate robust, evidence-based insights specific to Irish classrooms. Findings will inform best practice for CO2 monitoring and support the development of practical, cost-effective ventilation guidelines to promote healthier, more sustainable learning environments.