Principles of Natural Ventilation in Vernacular Architecture of Arid Regions (A Case Study of Tabatabaei House in Kashan, Isfahan, Iran)

Abstract

Climate plays an important role in both form and the performance of the building and its energy consumption. By designing a naturally responsive building, we can reduce the energy consumption and provide a comfortable, healthy and sustainable living space. Thermal comfort is defined in ASHRAE standard 55-74 as “that state of mind which expresses satisfaction with the thermal environment”. It’s one of the most important factors for improving the comfort and satisfaction of the occupants with their environment. The major variables of human thermal comfort are temperature, relative humidity and moisture, air movement, mean radiant temperature, metabolism/activities (MET) and CLO (clothing). Natural ventilation can provide thermal comfort and healthy indoor environment to the occupants. It can equip adequate breathing air, adequate ventilation of contaminants, adequate thermal conditioning and moisture and contribute to the well-being of the occupants. In order for natural ventilation to be effective, there should be a close relationship between the architecture and the air circulation. Regarding the rich history of architecture in Iran, it’s useful to analyze the sustainable features of the vernacular architecture of Iran in order to come up with methods to apply these strategies to modern architecture in similar climatic situations. Iran is a vast country and has different types of climate: mild and quite wet on the coast of the Caspian Sea, dessert and hot on the southern coast and the southeast, cold in high mountains, continental and arid in the plateau. In each of these climatic regions the form of the building is designed to provide the most thermally comfortable environment for the occupants. Being an architecture student in Isfahan, Iran, I have always wondered about the thermal comfort provided in different part of the vernacular architecture of that region without any use of non-renewable energy sources. I spent hours in the basements of these buildings without feeling any discomfort. Therefore in this research I will study the natural ventilation strategies in earth integrated vernacular architecture of hot and arid regions of Iran. This will be accomplished by developing 3D models of the case study from this region and examining them in Autodesk Flow Design and by drawing the natural ventilation diagrams of the building.