The document describes different types of badgirs, traditional wind towers used in Persian architecture for natural cooling and ventilation. It identifies five common styles of badgirs that vary based on the number and placement of vents, including unidirectional, two-directional, four-directional, and octagonal styles. It also explains two main functioning systems of badgirs - cooling by evaporation which is used in dry hot regions, and cooling by ventilation which occurs in humid warm areas and relies on rising hot air exiting through vents.

1. Types of Badgirs
Badgirs vary from one region to another. They
have many styles and different functioning. The
picture below shows the most known ones:
A. Unidirectional.
B. Two-directional.
C. Four-directional.
D. Octagonal with two vents on each side.
E. Four-directional with two false vents on
two opposite sides.
Functioning Systems of Badgirs
Cooling by evaporation:
Badgirs have vents on side from which the wind blows and on the opposite side. During the day
time; the wind enters the building and evaporates water causing a decrease in temperature inside the
building. This style of Badgirs is dominant in dry hot regions.
Cooling by ventilation:
Inside a building, the hot air rises because it is less dense whereas cool air sinks down since it is
denser. When there is no wind outside, Badgir allows the hot rising air to expire from the vents
leaving behind only cool air and thus the inner environment cools down. This type of Badgirs is
usually found in humid and warm regions.