Air flows from an area of high density to an area of low density; and it rises when slightly heated.health and fitness Updated: May 29, 2003 19:47 IST
A house should have the following devices to enhance natural ventilation.
Windows let in air. When a window and an open door (or a bigger window) are placed in line with each other unequal pressure is created and air moves from one opening to another. This is called cross ventilation and this ensures fresh air supply.
Air diffuses through fine meshes. These are preferred where privacy is required. But here the process is slow and needs to be supplemented with other types of ventilation.
These are excellent devices to keep the air circulating. They work on the theory of convection. Air flows from an area of high density to an area of low density; it rises when slightly heated and escapes from openings provided high up in the room and enters through inlets placed low. A narrow opening high up on the wall keeps the room cool in summer.