Integrating Vernacular Patterns and Modern Passive Design Strategies for Energy Optimization in Iran’s Hot-Arid Climate (Case Study: Qom City)

Shirdel, Amir Hossein; Olfat, Milad; Asadpour, Faezeh; Heidari, Mohammad Saber

doi:10.22034/ijumes.2026.2069856.1326

Integrating Vernacular Patterns and Modern Passive Design Strategies for Energy Optimization in Iran’s Hot-Arid Climate (Case Study: Qom City)

Document Type : Case Study

Authors

Amir Hossein Shirdel ¹

Milad Olfat ²

Faezeh Asadpour ³

Mohammad Saber Heidari ⁴

¹ Department of Architecture, Faculty of Architecture and Urban Planning, Shahid Beheshti University, Tehran, Iran

² Department of Art Education, Farhangian University, P.O. Box 14665-889, Tehran, Iran

³ Department of Architecture, University of Science and Technology of Mazandaran, Behshahr, Iran

⁴ Department of Architecture, Faculty of Art and Architecture, Tarbiat Modares University(TMU), Tehran, Iran

10.22034/ijumes.2026.2069856.1326

Abstract

The building sector is a major consumer of energy, particularly in hot-arid regions where intense summer heat, large diurnal temperature variations, and limited naturally comfortable periods increase dependence on mechanical heating and cooling. The aim of this research was to develop an integrated framework for improving thermal comfort in residential buildings in Qom city by combining the principles of Iranian vernacular architecture with contemporary climatic analysis. The research methodology employed a mixed qualitative–quantitative approach. In the qualitative phase, 34 candidate strategies were identified through a review of peer-reviewed studies, books, specialized reports, and documented examples of vernacular residential architecture in Iran’s hot-arid regions. After applying predefined inclusion and exclusion criteria, 20 passive and low-energy design strategies were retained. In the quantitative phase, Qom’s climatic conditions were evaluated using Climate Consultant and the ASHRAE Standard 55 thermal comfort model based on a standardized EPW typical meteorological year dataset (1991–2020), with separate analyses for the cold and hot seasons. The results and discussion showed that naturally comfortable conditions occur during only a limited portion of the year. During the hot season, two-stage evaporative cooling achieved the highest applicability, addressing 80.2% of selected hourly conditions. Solar shading, natural ventilation, building and courtyard orientation, vegetation, and high-thermal-mass materials were identified as the most influential passive design strategies. The conclusion indicates that the integrated screening and climatic validation process produced 20 operational strategies, providing an evidence-based framework for reducing mechanical energy demand, improving thermal comfort, and adapting traditional Iranian architectural principles in hot-arid regions.

Graphical Abstract

Integrating Vernacular Patterns and Modern Passive Design Strategies for Energy Optimization in Iran’s Hot-Arid Climate (Case Study: Qom City)

Highlights

· This research tackles the building sector's excessive energy consumption, which accounts for over 40% of global energy use and approximately 36% in Iran, focusing on optimization in hot and arid climates.

· The study uniquely integrates empirical strategies from Iran's rich vernacular architecture (e.g., windcatchers, courtyards, thick walls) with rigorous quantitative climatic analysis using specialized software (Climate Consultant) and the ASHRAE-55 comfort model.

· Analysis of nearly 30 years of climatic data for Qom reveals extreme conditions, with summer peaks of 44°C and winter lows of -2°C, resulting in a very limited period of natural comfort and a high dependence on mechanical heating and cooling systems.

· The research identifies and ranks the most impactful design strategies. Two-stage evaporative cooling (80.2% impact) and window shading devices (40.7% impact) were quantitatively validated as the most critical factors for achieving thermal comfort in the hot season.

· The study culminates in the formulation of 20 operational design strategies that merge passive vernacular patterns with modern technologies. This provides architects and designers with a practical guide for creating energy-efficient, culturally resonant, and comfortable buildings in Iran's hot and arid regions.

Keywords

Energy efficiency

Hot-Arid climate

passive design

Qom city

thermal comfort

vernacular architecture

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