Heating by radiation with infrared lamps
How does an infrared lamp heat a room, closed or open? This is a question that we are not used to asking ourselves. Despite this, unlike a wood fire or a radiator, the physical phenomenon by which infrared lamps can increase the temperature of a location is extremely interesting.
Brief notes on the diffusion of heat
Diffusion of heat is, in the common jargon, that physical phenomenon whereby an exchange of thermal energy takes place between two systems, the advent that determines the increase in the temperature of one of them. From this definition it is immediately clear that heat is a manifestation of energy and that it can pass from one system (which can be a body or an organism, for example), to another.
Heat transfer is always one-sided, which is why it will always happen from the warmer body to the colder body, until there is thermal equilibrium. The opposite is physically impossible. Logically, the difference in temperature between two systems and its change must be evaluated on the basis of a set of factors, for which all the dimensions of the systems must be considered.
Heating by radiation
Therefore, the heat always moves in a single “direction”; aware of this phenomenon, we can analyse how this movement takes place, or rather how it can occur. There are three modes of heat transfer:
What we are interested in is the last one listed, namely radiation, which is the physical phenomenon that allows infrared lamps to heat a location. Radiation occurs between two different surfaces with different temperatures and allows the transmission of heat through electromagnetic waves, in the specific infrared lamp, an infrared emission.
Radiation can therefore take place even without a third element interposed (such as air) even between two very distant surfaces, separated by vacuum. In fact on the one hand we will have a source that will emit energy, in the form of infrared; on the other, a surface of any kind in any stage that will absorb energy, converting it into a temperature increase.
Seen in these terms, radiation may appear to be something unnatural and completely artificial. Speaking of electromagnetic and infrared waves, one might perhaps think that it could lead to side effects; in fact, heating by radiation is the most natural and most widely used form of heating over the millennia of mankind’s history.
In fact, it is the way in which our planet receives heat from the Sun. Consequently, using an infrared lamp to heat an environment is, in a strictly physical sense and without too many paraphrases, the most similar way we have to create warmth in the same way as the Sun. Every day, in every kind of weather.