Infrared heaters produce heat energy, powered by electricity, natural gas or propane. Infrared heaters are comprised of heatproof resistance coil or a filament wire, often made up of tungsten; other alternatives are carbon, or alloys of iron, chromium, and aluminum.

In addition to providing a source of heat, these heaters can also be used for specific applications such as sterilization.

Infrared heaters are used to transfer heat energy through electromagnetic waves or radiation. No contact is needed for heat to be transferred to the object being heated, and infrared heaters can be used in a vacuum.

Infrared energy is transmitted at the speed of light but does not heat the air that it passes through. The energy is either absorbed or reflected by the objects that it meets. The temperature and physical properties of the object will dictate the efficiency of the process. Infrared radiation is similar to radio waves, visible light, ultraviolet, microwaves, and x-rays, and differs only in the wavelength produced.

The range for infrared radiation is from 0.7mm to 1000mm; the most useful heating occurs between 0.7mm and 10mm. Infrared heaters are typically classified by the wavelength of their infrared emissions. Practically, infrared heater efficiency depends on matching the wavelength to the absorption spectrum of the material being heated. Careful selection of the right infrared heater type is therefore important for heating efficiency.