To be a good thermal insulator, a material must be resistant to the conduction, convection and radiation of heat. A good insulator is made from an opaque, nonmetallic material without a crystalline structure, and its insulating properties may be enhanced by creating small air pockets inside its structure.Continue Reading
The reason metals conduct heat so well is that metallic atoms have a poor hold on their outermost electrons. This allows the electrons to flow from one atom to another easily, and they carry energy as they move. When one end of a metallic object is heated, this increase in temperature excites the electrons and causes them to flow, carrying the heat along the object and heating it evenly. Insulating materials such as plastics resist the flow of electrons, reducing heat flow through the material.
Air pockets are another way to increase insulation. Under normal circumstances, air can transmit heat through convection, flows of air created by differences in temperature and pressure. If the air pockets inside a material are separated from one another, however, these flows cannot happen. The heat also cannot conduct through the trapped air, reducing its ability to flow through the material. Winter coats and other insulated clothing often utilize this technique, as do the insulating materials inside the walls and attics of residential homes.Learn more about Thermodynamics
Substances absorb heat energy through three processes of heat transfer: convection, conduction and radiation. Convection transfers heat energy through fluid motion, such as in a liquid or gas. Conduction transfers interior heat through the tremors of atoms and molecules, and radiation transfers heat energy through electromagnetic waves.Full Answer >
Heat can transfer between objects in one of three ways depending on the medium: conduction, convection or radiation. Conduction occurs in solids, convection occurs in liquid or gas, and radiation occurs in virtually any medium, including a vacuum. The three methods of heat transfer have decreasing speed and efficiency, depending on the source and difference of temperature.Full Answer >
Heat flows from one object to another by conduction, convection or radiation, depending on the physical state of the medium through which it must flow. Heat always flows from a region of high temperature to a region of lower temperature. Without a temperature difference, there can be no heat flow.Full Answer >
Heat transfer works by transferring energy from one substance to another via convection, conduction or radiation. Particles in a substance are able to store energy and transfer it to other particles, often in the form of heat.Full Answer >