Masoud Esfandiari - PhD, Faculty of Architecture and Urban planning, Shahid Beheshti University, Tehran, Iran
Mohammad Reza Hafezi - PhD, Faculty of Architecture and Urban planning, Shahid Beheshti University, Tehran, Iran
Ardalan Aflaki - PhD, Faculty of Architecture and Art, University of Guilan, Rasht, Iran

The quality of the indoor environment depends on the quality of variables such as thermal comfort orindoor air. Natural ventilation as a tool can enhance the quality of the indoor environment by improvingthe thermal quality and indoor air. Also, natural ventilation helps to reduce the high demand for energyconsumption in the buildings, in which buildings have become one of the major sources of energyconsumption in urban with high energy demand. This study aims to review the state of the art concerningnatural ventilation. To achieve the aim the influence of natural ventilation on indoor air quality andthermal comfort has been investigated through a review of the literature. Indoor airflow as a significantparameter of natural ventilation has been reviewed in the international guidelines and standards. Thereview has implied to have appropriate indoor airspeed should be defined based on the time of the yearand microclimate, although a range of acceptable airflow is suggested by various standards. Also, aconflict might happen to suggest an airflow based on thermal comfort, air quality or energy saving.

Natural Ventilation; Indoor Air Quality; Airflow Rate; International Guidelines