Infrared is electromagnetic energy that emits from a hot source. The energy emitting from the source goes through air to hit the first object it “sees”; transferring the energy to the object and heating it up. The sun is a good example, but every object emits some infrared energy. There are a variety of ways to generate heat to serve as a catalyst in commercial processes. Resistance heat is one of the most common where resistance wire is energized with electricity and heat is thereby emitted in wavelengths from 1.0 to 4.0 microns.