Sunken garden is one of the elements of traditional Iranian architecture, formed with the attitude of conservation of environment and organizing a meaningful relationship with its surroundings. Many studies have been conducted to identify this element of traditional architecture and its functions, endorsing its valuable and considerable properties in respect for nature, harmony with the aims of sustainable development and energy conservation. One of the most important functions of this elements is providing cooling needs for residents in the hot summer months of desert areas of Iran without the need of fossil fuels consuming. The current article, as a descriptive-analytic study, aimed at a more comprehensive knowledge of passive cooling in sunken garden. To reach this goal, passive cooling and its types and sunken garden were first introduced. Then, their relationship with natural elements and the role of each element in achieving passive cooling in sunken garden were evaluated. The results revealed that sunken garden has been linked with natural elements in a way which cools this underground space of traditional buildings of hot and dry climate of Iran through heat prevention, heat modulation and heat dissipation.

Dezful city, located in southwest of Iran, has a hot and semi-humid climate. In the past, architectures used design solutions to provide the cold of living space. Shavadoon is one of the most important design for reaching this goal. Shavadoon is an underground space in traditional buildings of Dezful city designed with a trend of respect and protection of natural environment. Shavadoon, linked with its peripheral environment, provided an appropriate space for sheltering residents in summers hot weather without a need of energy of fossil fuels. Exploring the causes of thermal comfort in this underground space with no need to non-renewable energies was the aim of this article. In this article passive cooling of shavadoon was reviewed in a descriptive and analytic procedure. Results indicated that the architectural design of shavadoon is such that cool down the shavadoon through three types of cooling including the ground cooling, cooling through ventilation and evaporative cooling.