Significance of Vastu Purush Mandal
The goddesses assigned to particular directions, and names signifying their characteristics are essentially the different images and projections of the sun and the moon in their daily traverse through the sky.

East-South-West is considered as the solar kingdom and West-North-East is called the lunar kingdom. During sunrise, for the first 2-2.5 hours, the sun provides energy for promotion of life. It lies in the East direction and its primary energies are good for existence of all life-forms. The next three hours it starts radiating more and more energy in the environment and is called the state of Agni (fire). This is the time when it starts moving on its mission gradually, providing negative effects. During this period the sun lies in the South-East zone.

The next three hours, in its third phase, a complete glow and aura of the sun starts coming out with its full force and energy. This is called Yama- a scorching and devastating state of the sun. During this period, the sun lies exactly above the head, i.e., in South-mid-horizon. This is the reason why the South is called the direction of Yama (Lord of death). After giving out all its radiation, the following three hours the sun rules over the entire horizon with its complete command. This is called Gagan, a state associated with sorrow due to the sun' s excess thermal activity and its location in the South- West. At sunset it cools down and directs its rays towards the moon for its night-reign.

In fact, the vastu Purush mandal represents images of goddesses according to the effects of the sun and its position in that particular direction ( Fig.4.2A, 4.2B). With reference to the cosmic environment, these images exactly fit the sun's position in the sky.