Convection

Understanding Convection

• Convection is a process of heat transfer that occurs in gases and liquids due to the movement of fluid particles.
• The process starts when a fluid (gas or liquid) is heated, it expands and becomes less dense.

The Process of Convection

• Heating causes the fluid particles to gain energy and move faster.
• As a result, the heated, less dense fluid will rise.
• There will be a displacement of the cooler, denser fluid which will move to replace the rising fluid.

Convection Currents

• This process of hot fluid rising and cool fluid sinking sets up a circular motion known as a convection current.
• Convection currents are responsible for the circulation of heat in systems like the Earth’s atmosphere, oceans, or a pot of boiling water.

Practical Examples

• An example of convection in action is a radiator heating a room. The air close to the radiator becomes warm, rises, and then cools, and sinks back down, creating a circular air movement or convection current.
• Another example is ocean currents, where warm water rises to the surface, cools down as it moves towards the poles, sinks, and then is warmed again as it is drawn back towards the equator.