Passive cooling paint enabled by rational design of thermal-optical and mass transfer properties
- Jipeng Fei
- Xuan Zhang
- Di Han
- Yue Lei
- Fei Xie
- Kai Zhou
- See-Wee Koh
- Junyu Ge
- Hao Zhou
- Xingli Wang
- Xinghui Wu
- Jun-Yan Tan
- Yuheng Gu
- Yongping Long
- Zhi Hui Koh
- Su Wang
- Panwei Du
- Tangwei Mi
- Bing-Feng Ng
- Lili Cai
- Chi Feng
- Qiaoqiang Gan
- Hong Li
2025-06-05
Integrating radiative and evaporative cooling shows promise for enhancing passive cooling, but durable self-curing integrated cooling paints remain underdeveloped. We designed a modified cementitious structure with advanced thermal-optical and mass transfer properties, boosting cooling power while ensuring durability, mechanical strength, and broad adhesion. The paint achieves 88 to 92% solar reflectance (depending on wetting), 95% atmospheric window emittance, ~30% water retention, and self-replenishing properties, maintaining stable optical performance even when wet. Field tests in tropical Singapore demonstrated superior cooling performance compared with commercial white paints. Pilot-scale demonstrations highlighted consistent electricity savings under varying weather conditions, supported by theoretical modeling. By leveraging sustainable water evaporation and thermal radiation, this paint offers a practical and long-term solution for mitigating the urban heat island effect.