Dr. Shahin Heidari - Assistant Professor, Deputy of Chancellor Ilam University

This paper explores the potential of using natural ventilation as a passive cooling system for building designed.It is clear that when air movement cools the human body he/she will be comfortable at temperature higher than the maximum comfortable temperature for still air. A number of studies have examined air movement and comfort under warm conditions. Tanabe and Kirmua (1994) conducted an experimental work at 50% RH under different level of air speed. They found preferred speed at 28ºC to be 1.0 m/s, at 29.6 ºC, 1.2 m/s and at 31.3ºC, 1.6 m/s.Although we have a very good background in terms of such a good strategy, however,passive design elements are mostly ignored in new buildings in Iran and people are concerned with the rising costs of electricity and fuel. In their buildings air conditioning is used during hot hours of the days. During the cooler hours, most people are still willing to open their windows and let fresh air in. The problems with current designs have prompted signers to rethink their designs,particularly because of an increasing awareness of sustainability. To conserve energy and reduce Co2 emissions. It is important to design energy efficient buildings.