Even with prices on infrared grills dropping, backyard grilling enthusiasts may consider the cost of the technology -- anywhere from $500 for tabletop models to $1,000 for free-standing versions as of 2011 -- a splurge [source: Associated Press]. (Perhaps adopters have trimmed from their grilling-related budgets, buying smaller steaks, more in-season vegetables and fewer novelty aprons.)
Infrared heat may be a hot new trend in grilling, but this type of heat has been occurring naturally since the dawn of time. In fact, everything with a temperature above absolute zero (which is equal to -459.67 degrees Fahrenheit or -273.15 degrees Celsius) emits at least a little infrared radiation. If you're wondering how this ancient, ubiquitous form of heat has been harnessed for home cooking use, it will help to understand how it's generated.
Infrared waves are part of the electromagnetic spectrum, sandwiched between visible light waves and microwaves. Within the infrared range, different types of infrared waves are characterized by frequency -- near, mid or far -- based on how many waves pass a given point each second [source: Study Physics]. At certain wavelengths within the infrared range, infrared waves create heat that human beings can sense.
Near infrared waves, like those activated by pushing a button on a television remote control, have the shortest frequencies and don't emit heat that humans can sense. Far infrared waves, however, have longer frequencies and are interpreted by humans' temperature-sensitive nerve endings as heat. For example, you can feel infrared heat when you're outdoors in the sunlight, when you walk barefoot on a warm sidewalk or when you stand near a wood-burning fireplace.
Therefore, infrared heat is present to some degree in any type of grill, from charcoal to wood fired to gas. As the temperature of a grill increases, it emits a greater amount of infrared heat. A charcoal grill can heat to about 700 degrees Fahrenheit (371 degrees Celsius), whereas a traditional gas grill typically reaches about 750 degrees Fahrenheit (398 degrees Celsius). An infrared grill, however, averages about 900 degrees Fahrenheit (482 degrees Celsius) and can reach up to 1,600 degrees Fahrenheit (871 degrees Celsius) -- the same temperature required for rocks to start melting near the Earth's core [source: Hunter, Associated Press, Oregon State].
This intense heat is then transferred to foods, a process we'll explore in greater detail on the next page.