Convection is a transfer system that carries thermal energy from one area to another.
The etymology of convection refers to the late Latin word convectio , which refers to the "act of transporting." The term is used in the field of physics to refer to the mode of propagation of a magnitude in a fluid due to differences in density .
Heat propagation
The idea of convection is usually linked to the propagation of heat in air or water. It is a transfer system that carries thermal energy from one area to another.
When two bodies meet at different temperatures, a heat flow is produced. The body that registers a higher temperature, in this framework, transfers heat to the one that is at a lower temperature by convention. It is important to mention that the flow is due to the movement of the molecules .
Therefore, when there are two liquids; two gases ; or a liquid and a gas at different temperatures, the process of convection involving heat transfer occurs. This can be seen in the operation of radiators , for example.
If a radiator is turned on, natural convention causes a flow of heat. As the air surrounding the radiator heats up, its density decreases and it moves upwards, since it now weighs less than the ambient air. All you have to do is place your hand over the radiator to feel the rising heat.
In meteorology
In the field of meteorology , on the other hand, convection is the vertical movement of air . This phenomenon occurs naturally in the atmosphere due to the sun's rays, which heat the Earth's surface and then this heat is transmitted to the adjacent layer of air, causing it to decrease in density and rise.
When the temperature of a parcel of air increases and its pressure remains constant, an increase in its volume and a decrease in its density are perceived. As a result, the air rises due to the effect of buoyancy, just as it happens with helium balloons (a substance less dense than air).
Convection oven
In recent decades, technological advances in different areas of industry have presented us with several alternatives to products that we considered essential, such as kitchen appliances. The oven is no exception, as there is currently a variety to consider when buying one, since there is probably one that is more suitable for each home than the rest. The convection oven generates an air current that pushes the heat towards the food , and in this way it heats it in less time and with better results.
Convection ovens push heat toward the food.
To achieve this, a convection oven uses a heating element (like many other electric ovens) and a fan that blows behind it to send heat in the direction of the trays. The current is continuous and even, which is why the food is well cooked. A traditional oven does not actively move the heat, so it depends on the proximity of the food or on natural radiation; this results in a waste of energy and a lack of uniformity in cooking .
Thanks to convection, the heat reaches all corners, also improving the cooking of the less exposed parts of preparations such as pizzas or empanadas, and even the base of sliced vegetables, for example, which in a traditional oven are only cooked on top. In short, this technology offers a series of very tempting benefits, both for the pocket of those who pay the electricity bill and for the palates of diners.