The main objective of the poultry housing and equipment is to provide the optimum condition for birds to achieve their maximum genetic potential. In Iranian poultry industry, most of older houses are smaller buildings without proper ventilation, heating, insulation, equipment and automation systems. This has led to an increase in energy consumption and poor performance and low efficiency of commercial poultry operations. Due to the low price of fuel and electricity in Iran, little attention has been paid to control energy consumption. One of the problems of most poultry houses in the country is the lack of minimum ventilation system or its inappropriate application. This issue, in addition to problems in controlling the environmental conditions of the houses, has led to an increase in fuel consumption. The tunnel ventilation system, due to its ability to generate high air velocity in hot weather, especially in humid areas, is more useful than other types of ventilation. However, surveys show that in most poultry houses, the air velocity is below optimum. Similar to other parts of the world, many new poultry houses are being built larger. Although larger houses increase efficiency and reduce production costs, their successful use depends on factors such as engineering considerations during construction and on properly designed and installed heating and ventilation systems. With the increase in fuel and labor costs and the introduction of modern poultry production systems and government support, the process of retrofitting and improvement of the poultry houses is evident.