The effect of wind-catchers el-malaqef- on the internal natural ventilation in hot climates with special reference to Egypt : Ahmed Abdel_Wahab Ahmed Rizk, Mohamed Abd Elmawgoud Abd Elghaffar.

Abstract EN

The research problem has two parts.

The first one expresses how to deliver air current (flow movement) due to wind pressure to cover all home parts.

The other part expresses how to achieve the thermal comfort in the conditions of Egypt such as high temperatures and low wind speed of the prevailing cold wind.

In this work, the effects of the geometrical characteristics of wind catchers on the internal natural ventilation is studied.

The aim of this study is to find a way to increase the wind speed from wind catcher all over the internal surrounding spaces.

Small physical models is used to derivate the optimum geometrical characteristics of wind catchers that achieve the objective of this research than actual models.

Also, the dimensions of the models of wind catchers are analyzed : the effect of the following items on air speed : the mainly second part discusses the controversial effects of the geometrical properties of wind catchers on air speed at wind catcher’s air entries (inlets) and air exits (outlets).

These effects are : 1- Different orientations of the entry openings.

Different inlet/outlet area ratio 2- 3- Different numbers and locations of air exits.

4- Cross-areas of the air tunnel and its different forms.

The roof angles of wind-catcher 5- The conclusions of the paper can summarize the conditions under which air speed - at both inlet and outlet openings increases as follows : when the long axis of the air-entry opening is perpendicularly placed to the wind direction.

When the inlet opening area is smaller than the outlet opening area.

When the outlet opening is faced inlet opening.

When the air tunnel cross-area gets smaller or turns into a circular shape.

And when the wind catcher roof angle is between 30º and 55º.