A systematic review of the impact of cool roofs on thermal comfort and energy efficiency of buildings in hot and dry climates

Subject Areas : City architect

shokouh sadat asadollahi ¹ , Mansoureh Tahbaz ^{2 *} , Niloufar Nikghadam ³ , Mahnaz mahmoodi zarandi ⁴

1 - Department of Art and Architecture, ST.C, Islamic Azad University, Tehran, Iran.
2 - Department of Architecture and Urban Planning, Shahid Beheshti University, Tehran, Iran
3 - Department of Architecture, ST.C, Islamic Azad University, Tehran, Iran
4 - Department of Architecture, NT.C, Islamic Azad University, Tehran, Iran

Received: 2025-05-29 Published : 2025-06-11

Keywords: Cool roof, Thermal comfort, Energy efficiency, Hot and dry climate, Passive design, Systematic review,

Abstract :

State the problem: In hot and arid climates, thermal discomfort and excessive cooling energy demand are major challenges in achieving sustainable building design. Cool roofs, as a passive architectural strategy, reduce roof surface temperature by reflecting solar radiation, thus improving indoor thermal comfort and energy efficiency. Objective: Aim: The aim of this article is to provide a systematic review of international and domestic research in this field. This study presents a systematic review of literature published between 2000 and 2025 on the impacts of cool roofs on thermal comfort and energy performance of buildings in hot and dry climates. and "What factors (materials, design, location, maintenance) play a role in its effectiveness?" Research method A comprehensive search was conducted in Scopus, Web of Science, ScienceDirect, SID, and MagIran databases, and following PRISMA guidelines, 15 studies were selected for in-depth analysis. Results reveal that cool roofs can reduce indoor air temperatures by up to 5°C and cooling energy consumption by 15–40%. A wide range of technologies were analyzed—from traditional white surfaces and nanocoatings to advanced PCM and ventilated systems—showing varied effectiveness depending on climatic, material, and maintenance conditions. Tips The study critically evaluates aligned and divergent findings across the literature, identifies key influencing factors, and proposes directions for future research. Conclusion: This review provides a practical reference for architects, engineers, and energy policymakers engaged in climate-responsive design in arid regions.

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