Heat Adaptation in Street Markets: The Role of Fog Cooling Systems in Sales Growth

Climate change is intensifying extreme summer heat, negatively affecting public health and the vitality of urban open spaces. Attendance in outdoor spaces serves as an indicator of thermal comfort, as users naturally avoid thermally uncomfortable environments. Although various cooling strategies have been implemented to improve thermal conditions, their potential socioeconomic benefits through enhanced user activity have received limited attention. This study investigates how fog cooling systems in street markets contribute to sales performance through improved thermal comfort for visitors. The research analyzed daily sales growth rates during summer months from 2017 to 2021 in Seoul, comparing markets equipped with fog cooling systems to typical markets. Using a difference-in-difference estimation with controls, the results revealed that fog-equipped markets showed an approximately 17% increase in daily sales compared to typical markets from the 2017 baseline to 2021. Notably, when comparing sales between moderate April and the hottest month of August, fog-cooled markets maintained steady sales levels, while typical markets experienced a sales decline during this comparison. The fog cooling systems, known to reduce ambient temperatures by 3°C–5°C in street markets, demonstrated effectiveness in maintaining market activities during hot periods. These findings reveal a pathway from technological intervention to broader social impacts: fog cooling systems improve thermal comfort, which leads to extended visitor stays and increased foot traffic, ultimately resulting in higher sales performance. Field observations and interviews with market managers support this relationship, showing improved visitor satisfaction and longer shopping duration. Beyond its environmental merits, this research provides empirical evidence that fog cooling systems can enhance economic activity in urban street markets and offers actionable insights for urban planning professionals seeking to integrate microclimate adaptation into broader revitalization and policy efforts.