Climate Elements 1. Knowing the sun's patterns at a given site will help in determining the location and shape of the building. The five principles of air movement are velocity, direction, pressure, density, and the venturi effect. When air encounters an obstruction, it tends to continue moving in the same direction and flows around the object. Differences in pressure causes air to move.
Convection is the transmission of heat by the mass movement of the heated particles.
When air flow is channeled and restricted, the pressure rises and the velocity increases, this is called the venturi effect. Wind patterns can be compared to the movement of water in a stream. The wind patterns near large bodies of water are affected by heat gain, heat loss, and heat storage variations between land and water. In valleys, wind moves uphill during the day as the sun warms the air causing it to be less dense and at night air flows back down the valleys as it cools and becomes heavier. Wind direction and vegetation affects the level of humidity.