Energy which when transferred to a surface causes it to rise in temperature can be transferred in 3 ways. Conducted, Radiated, and Convected. Energy always transfers from a warmer surface to a colder one, trying to bring both objects to the same temperature. During our Energy Audit & presentation we will explain how all 3 types of Energy Transfer are at work in your home.

What follows is a more technical discussion care of Wikipedia, the free encyclopedia

Radiant energy is the energy of electromagnetic waves.[1] The quantity of radiant energy may be calculated by integrating radiant flux (or power) with respect to time and, like all forms of energy, its SI unit is the joule. The term is used particularly when radiation is emitted by a source into the surrounding environment. Radiant energy may be visible or invisible to the human eye. The term "radiant energy" is most commonly used in the fields of radiometry, solar energy, heating and lighting,

From Wikipedia, the free encyclopedia

  (Redirected from Heat conduction)
See also: electrical conduction
In heat transfer, conduction (or heat conduction) is the transfer of thermal energy between neighboring molecules in a substance due to a temperature gradient. It always takes place from a region of higher temperature to a region of lower temperature, and acts to equalize temperature differences. Conduction takes place in all forms of matter, viz. solids, liquids, gases and plasmas, but does not require any bulk motion of matter. In solids, it is due to the combination of vibrations of the molecules in a lattice and the energy transport by free electrons. In gases and liquids, conduction is due to the collisions and diffusion of the molecules during their random motion.
Heat can also be transferred by radiation and/or convection, and often more than one of these processes occur in a given situation.

From Wikipedia, the free encyclopedia

"Radiant heat" redirects here. For the heating method, see Radiant heating.

Hot metalwork from a blacksmith. The yellow-orange glow is the visible part of the thermal radiation emitted due to the high temperature. Everything else in the picture is glowing with thermal radiation as well, but less brightly and at longer wavelengths that the human eye cannot see. A far-infrared camera will show this radiation (See Thermography).

This diagram shows how the peak wavelength and total radiated amount vary with temperature. Although this plot shows relatively high temperatures, the same relationships hold true for any temperature down to absolute zero. Visible light is between 380 to 750 nm.
Thermal radiation is electromagnetic radiation emitted from the surface of an object which is due to the object's temperature. An example of thermal radiation is the infrared radiation emitted by a common household radiator orelectric heater. A person near a raging bonfire will feel the radiated heat of the fire, even if the surrounding air is very cold. Thermal radiation is generated when heat from the movement of charged particles within atoms is converted to electromagnetic radiation. Solar radiation heats the earth during the day, while at night the earth re-radiates some heat back into space.

From Wikipedia, the free encyclopedia

This figure shows a calculation for thermal convection. Colors closer to red are hot areas and colors closer to blue are cold areas. In this figure, a hot, less-dense lower boundary layer sends plumes of hot material upwards, and likewise, cold material from the top moves downwards. This figure is from a model of convection in theEarth's mantle.
Convection is the movement of molecules within fluids (i.e. liquids, gases and rheids). Convection is one of the major modes of heat transfer and mass transfer. In fluids, convective heat and mass transfer take place through both diffusion – the random Brownian motion of individual particles in the fluid – and by advection, in which matter or heat is transported by the larger-scale motion of currents in the fluid. In the context of heat and mass transfer, the term "convection" is used to refer to the sum of advective and diffusive transfer.[1]

A common use of the term convection leaves out the word "heat" but nevertheless refers to heat convection: that is, the case in which heat is the entity of interest being advected (carried), and diffused (dispersed). There are two major types of heat convection:

1. Heat is carried passively by a fluid motion which would occur anyway without the heating process. This heat transfer process is often termed forced convection or occasionally heat advection.
2. Heat itself causes the fluid motion (via expansion and buoyancy force), while at the same time also causing heat to be transported by this bulk motion of the fluid. This process is called natural convection, or free convection. With natural convection, heat transport (and related transport of other substances in the fluid due to it) is generally more complicated.

Both forced and natural types of heat convection may occur together (in that case being termed mixed convection).
Convective heat transfer is a mechanism of heat transfer occurring because of bulk motion (observable movement) of fluids (see convection for concept details). This can be contrasted with conductive heat transfer, which is the transfer of energy by vibrations at a molecular level through a solid or fluid, and radiative heat transfer, the transfer of energy through electromagnetic waves.
As convection is dependent on the bulk movement of a fluid it can only occur in liquids, gases and multiphase mixtures.