Have you ever touched a surface warmed by the sun on an early spring day and felt a pleasant warmth, even when a thermometer indicates cold? The principal behind infrared heating lies in understanding how the sun rays work. They are a mixture of electromagnetic waves ranging from infrared (IR) to ultraviolet rays (UV) which travel through the atmosphere without the need of air or any other medium to carry them. When sunrays reach the object, they heat it from the inside leaving it warm without heating the air around it. Infrared rays are just under the visible light range in the electromagnetic spectrum.
Infrared heating works by directly heating objects, walls, floors, human body, or anything located near the heat source, instead of heating the empty air. Then heated objects release their heat into the environment.