The Effect of Solar Chimney on Building Ventilation in Different Climates of Iran

The growth of energy consumption in modern societies has confronted world with threatening changes along with the peril of depletion of fossil resources. Therefore، exploiting the methods of sustainable design has found a high status in international planning and policy making. The most energy consumptions are happening in the building industry، about 40%، and the major part of which is spent for cooling، heating and ventilation. Therefore، using suitable measures to reduce energy consumption has a great influence on energy balance of building. Solar energy for natural ventilation has been used for centuries. Air ventilation is necessary for removing or depleting pollution that can be supplied through solar chimney. Solar chimney is a simple idea to increase natural ventilation in surrounding spaces by using solar energy and chimney effect in an air gap. The driving force in solar chimney is buoyancy force. The solar energy absorbed by chimney causes heat up the air in the chimney so that the air flows upward because of the stack effect. That can be a driving force to enhance natural ventilation. Therefore، the breeze inside the space lets the fresh air enter the space through window. There are a lot of cases which show the use of solar energy for ventilation by some absorption effect in building. The commonest design of solar chimney for ventilation is in vertical form. In the present study، the effect of solar chimney on ventilation rate has been examined in four cities of Iran with different climates. The cities were Rasht (moderate and humid climate)، Tabriz (cold climate)، Isfahan (hot and dry climate)، Bandar Abas (hot and humid climate). Due to the lack of access to the implemented samples، the computerized simulation was used as an alternative method for field studies، the results of which by Energy Plus software in four cities of different climates show that the most suitable city is Isfahan (hot and dry climate) and the maximum ventilation is obtained there. There are also other factors that impacts solar chimney efficiency. Three cities (Isfahan، Yazd، Shiraz) of hot and dry climate were investigated to define their impact of latitude on ventilation rate.