Traditional clay pot coolers as drinking water cooling technology for urban heat adaptation in Bangladesh

Abstract

Global warming is intensifying heat waves in tropical nations such as Bangladesh, where summer temperatures often exceed 35 °C with high humidity. These conditions pose severe health risks for outdoor workers—rickshaw pullers, hawkers, construction labourers, and traffic personnel—who lack access to conventional cooling technologies. This review examines clay pot coolers (CPCs), a traditional, low-cost, energy-free method for cooling drinking water. CPCs use evaporative cooling and can reduce stored water temperatures by 5–15 °C, though performance depends strongly on climate, clay properties, and design. To illustrate these limits, a desk-based analysis using NASA POWER climate data for Dhaka (2022–2024) was conducted. Results show cooling potential up to ∼14 °C in the pre-monsoon but less than 4 °C in the humid monsoon, underscoring the need for targeted design adaptations. The review also integrates engineering, public health, and policy perspectives, highlighting gaps in material optimisation, standardisation, and adoption pathways. CPCs are assessed within urban heat adaptation strategies and their contributions to health, clean water, sustainable cities, and climate action SDGs. They offer an affordable, scalable solution for protecting vulnerable communities in heat-stressed cities.