Natural Ventilation Strategies to Prevent Airborne Disease Transmission in Public Buildings

This paper evaluates the effectiveness of natural ventilation as a health and safety strategy in municipal buildings, focusing on its capacity to ensure indoor air quality and limit airborne disease transmission. Natural ventilation can be incorporated into building design as the primary mechanism for achieving the required indoor air quality, equipping buildings with operable windows based on their intended occupancy. Using 11 public buildings in Mostoles, Spain, as case studies, the research applies a quantitative methodology based on carbon dioxide concentration to estimate ventilation rates and theoretical occupancy thresholds. The findings reveal that cross ventilation is the only natural method capable of meeting air renewal rates recommended by health authorities, particularly the IDA2 air quality standard and three to five air changes per hour suggested to reduce disease spread. However, 53% of the assessed spaces lacked cross ventilation capacity, underscoring the need to integrate natural and mechanical systems. The study proposes a replicable model to assess and adapt indoor occupancy based on real ventilation capacity, offering a practical tool for decision-making in public health, energy efficiency, and architectural design. Ultimately, the research supports the strategic use of natural ventilation as a low-cost, scalable intervention to enhance environmental quality in public facilities.