Energy Resources and Transfer: Convection

Convection occurs in fluids, i.e., liquids and gases, which can easily move and transport thermal energy.
It’s the process by which heat is transferred from a hotter region to a cooler region within a fluid.
Convection begins when a fluid becomes heated; this makes it expand and therefore decrease in density.
The less dense, warmer fluid then rises, and colder, denser fluid rushes in to take its place, then this colder fluid itself is heated, rises, and the cycle continues. This creates a convection current.
The constant flow of fluid resulting from these changes in temperature and density transport heat energy throughout the fluid.
Convection currents are the reason why radiators are usually placed near the floor – so they can heat the cooler air at the bottom, which then rises to heat up the rest of the room.
They also drive several natural phenomena, such as ocean currents, winds, and the boiling of liquids.
Convection is also crucial in several cooking processes. For instance, boiling water and baking in an oven utilise convection to heat food.
Using insulation can reduce heat transfer by convection. For instance, in houses, insulating the loft minimises the convection currents, which reduces heat loss.
Convection, along with conduction and radiation, plays a crucial role in global weather patterns.
In convection, the transfer of energy is through moving particles, unlike conduction, which happens in solids and doesn’t involve particle movement.
Finally, understanding convection is crucial for many industries and technologies, from designing heating systems and boilers to understanding natural disasters like typhoons and earthquakes.