Purpose: This study examined the field performance of energy recovery ventilation (ERV)-related ventilation improvements for indoor air quality (IAQ) in public school food service facilities through a secondary exploratory analysis of previously reported field data and certified ERV performance information. Research Design and Data: Pre- and post-improvement reduction rates for seven pollutants (PM10, PM2.5, CO2, NO2, CO, TVOC, and HCHO) were compiled for cooking rooms and cafeterias in three schools, of which two provided matched before-and-after data. Pollutant reduction patterns were assessed descriptively, and certified ERV indicators, including airflow capacity, power consumption, heat-recovery efficiency, and noise level, were summarized as technical performance information. Because raw repeated-measurement data were unavailable, inferential testing, formal correlation analysis, and causal modeling were not performed. Results: Particulate pollutants showed the most consistent reductions, with PM10 and PM2.5 exceeding 55% across the four matched space-level observations. NO2 and CO showed moderate reductions, whereas CO2 showed smaller and more variable changes. TVOC showed inconsistent or negative responses, suggesting the influence of non-ventilation sources such as cooking materials, cleaning agents, and indoor chemical emissions. The available data were insufficient to formally evaluate the relationship between certified ERV airflow capacity and pollutant reduction. Conclusions: ERV-related ventilation improvement appears effective for reducing cooking-generated particulates in public school food service facilities. However, VOC control requires source-management strategies in addition to ventilation. These findings provide preliminary field-based evidence for larger multi-site validation studies and future operation-level performance assessments.