What is convection?
Heat can be transported by radiation, conduction or convection. Low temperature bodies like the earth’s surface and the atmosphere emit infrared radiation. Infrared radiation is ineffective in transmitting heat upward in the atmosphere because infrared radiation is absorbed by the atmosphere, mainly by water vapor and carbon dioxide. Conduction is the primary heat transport process in solids.
The second way heat travels is by convection. ConvectionThe circulatory motion that occurs in a gas or liquid at a nonuniform temperature owing to the variation of its density and the action of gravity. is the rising of warm air from an object, such as the surface of Earth. Convection allows heat to travel through both gases and liquids, moving from warmer areas to cooler areas.
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Convection is broadly the movement of any molecules through any fluid state, including liquids and gasses. It is the primary form of heat and mass transfer on Earth, and can be found in many systems around the world. Many people are familiar with convection from heating their food or their houses, and it also plays a pivotal role in creating the weather conditions on the planet. There are two main types of convection: forced convection and natural convection. Forced convection occurs when the medium transferring the heat is moving on its own, such as when air is being pushed by a fan. In this case, the heat is disbursed by the movement of the air of fluid, but it isn’t actually causing the movement. Sometimes forced convection will be referred to as heat advection, as well. Natural convection occurs when the medium transferring the heat is being inspired to move by the heat itself. This happens both because the medium expands as it heats up, as in the case of gases, and also because bu
Convection is the transfer of energy from one point to another by the movement of a medium, such as air or water. Heating most substances causes them to become lighter, and, in a gravity field such as we experience here on Earth, the substance will rise, because it is lighter than the surrounding air. So the woodstove or oil filled heater on one side of the room will cause air to become warm, which causes it to rise, which pulls cool air into the area of the heat source. This is how a heater on the other side of the room can make the whole room warm. The other forms of energy transmission are radiation, the heat that you feel on your hand when you hold your hand toward the heat source, and conduction, which is what happens to the heat from a stove burner beneath a pan. The pan conducts the heat to the contents, making them warmer.
