What is Infrared Heat?

Infrared radiation is electromagnetic radiation with a wavelength longer than that of visible light, but shorter than radio waves. Infrared means "below red" referring to red being the color of visible light of longest wavelength.

The infrared portion of the spectrum has many uses including:

• targeting and tracking by the military
  
• remote temperature sensing
  
• short-ranged wireless communication
• weather forecasting

In infrared astronomy telescopes equipped with infrared sensors are used to penetrate dusty regions of space, such as molecular clouds.

Infrared energy causes vibration in a molecule. Infrared spectroscopy exams the absorption and transmission of photons in the infrared energy range, based on their frequency and intensity.

Infrared radiation is often known as heat radiation. Infrared light from the sun accounts for 50% of the heating of the Earth, the rest being caused by visible light. Unlike heat transmitted by thermal conduction or thermal convection, radiation can propagate through a vacuum.

What is Radiant Heating?

Infrared transfers heat by radiation. There are three methods of transmitting heat:

• radiation
• convection
• conduction

Everything emits infrared radiation. The radiant heat you feel from an oven or a fire is infrared radiation. Greenhouse gases in the atmosphere trap some of this infrared radiation, and keep the earth habitable for life.

Using this same infrared heating principle, infrared energy from a heating element or bulb can be used to heat animals, birds, people, or objects). This infrared energy is identical to the sun's energy but without the UV rays. Infrared heat does no heating until it is absorbed by the subject from the heater. The heated subject then gives off some heat to help heat the surrounding air.

Convection heat uses natural air circulation currents to transfer heat. Convection involves two basic principles:

• cold air displaces warm air
• warm air rises in the presence of cold air

In convection, heat is transferred using air currents to transport energy through a space.

Heat conduction is the transmission of heat across matter. Heat transfer is always directed from a higher to a lower temperature. Denser substances are usually better conductors. Metals are excellent conductors.