Infrared Heat is the therapeutic warmth you feel from the Infrared Energy or Light of the sun.  Radiant heat is simply a form of energy that heats objects directly through a process called conversion without having to heat the air between. Radiant heat is also called infrared energy or IR. The electromagnetic spectrum is divided into three segments by wavelength, measured in microns or micrometers.

  • (a micron = 1/1,000,000 of a meter)
  • .076 to 1.5 microns = near or close Infrared Energy
  • 1.5 to 5.6 = middle or intermediate Infrared Energy 
  • 5.6 to 14 = far or long wave Infrared Energy

The Far Infrared segment of the electromagnetic spectrum occurs just below, or "Infra" to, red light as the next lowest energy band.  The "Far" part of infrared light are the longer wavelengths.  

This band of light is not visible to human eyes but can be seen by special cameras that translate infrared into visible colors.  We can, however, feel this type of light, which we perceive as heat.

The sun produces most of its energy in the infrared segment of the spectrum.  Our atmosphere has a "window" in it that allows infrared rays -- in the 7 to 14 micron ranges -- to safely reach the earth's surface.  When warmed, the earth radiates infrared rays in the 7 to 14 micron bands with its peak output at 10 microns.