TESY infrared heater incorporates Golden Tube heating element made of wire tungsten coil placed in a sealed quartz tube. The tube is coated with special chemical film, which filters UV rays and most of the visible light spectrum. Hence, infrared radiation is prevailing.
Short electromagnetic waves travel faster in air. Short-wave infrared rays heat the body, as the ray falls only on it, without heating the surrounding air. A good example is the eﬀect created when we move from a shadow place into the sunlight: though the temperature is the same, but the temperature in the sunlight is felt higher. This phenomenon allows sunbathing during winter holidays, when temperature is low. On the other hand, long-wave infrared rays do not have the same eﬀect. They heat the surrounding air therefore it takes longer for the heat to be felt.