A lot has been published about the heating and insulating powers of infrared radiation. In this article, we will explain why infrared has this insulating effect, how it works, and how you can maximise it to insulate your home.
What was infrared again?
Infrared radiation is a band on the electromagnetic spectrum between visible light and microwaves (think of the microwave oven). All objects warmer than 0 kelvin (-273 °C) emit infrared radiation. Objects which are colder than the ambient temperature absorb infrared (heat always moves towards cold).
Unlike other energy waves (such as UV-A), thermal infrared radiation is not absorbed by the air, but transmitted (let through). The radiation stays intact until it is absorbed by an object or surface. No energy is lost along the way (the radiation is not weakened). The same goes for sunlight. A lot of infrared radiation is the result of sunlight heating up surfaces and objects, which changes the frequency of that radiation and creates infrared. Wherever sunlight is absorbed, infrared can continue to heat.
Infrared has a wavelength of 780 nanometres to 1 micrometre. The wavelength depends on the temperature. Thermal infrared with a wavelength between 8 and 12.5 μm emits the most energy. Humans, with an average body temperature of 37°C, only emit 'far infrared' radiation (equivalent to approx. 100 Watt).
The above graph depicts the conductivity of the 'air' for far infrared radiation and shows that the intensity of the radiation is at an optimum level at this frequency.
How can infrared be a source of heat?
Two Amsterdam physicists (Bakker and Nienhuys, from the Institute for Atomic and Molecular Physics) have researched how it is possible that water (the water molecule) falls apart (evaporates).
They ’fired' infrared light pulses with a wavelength of around 3000 nanometres at liquid water. This wavelength corresponds to a frequency of 1014 Hertz, equal to the frequency of oscillation of the hydrogen atoms in the water molecule. They studied the oscillating atoms and saw that this additional oscillation energy weakened and eventually broke the bond between the hydrogen and oxygen atoms, thus making the water molecule 'fall apart'.
This effect occurs with so-called 'far infrared radiation', so it does not require any extreme heat or special equipment. It is a very common, everyday phenomenon. In order to make moisture evaporate, however, even in places without any sunlight (e.g. crawl spaces and cavity walls or roofs), it is essential for the infrared to be reflected. That is where Isobooster comes in.
The ‘Isobooster effect’
As mentioned above, thermal infrared is not absorbed by the air, but stays at full power until it hits an object or surface that aborbs it. Rather than absorbing this energy wave, Isobooster insulation foil reflects the infrared radiation, boosting the evaporating effect and ‘taking full advantage’ of it. As long as the vapour is allowed to escape, the air that remains is dry. Dry air insulates twice as well as humid air.
Try before you buy? Experience the effect of reflected infrared radiation yourself by holding a piece of aluminium foil close to your face. You will soon find yourself breaking out in a sweat!
Take a crawl space, for example. The heat from your home warms up the floor, after which the floor radiates heat to the -always colder- crawl space underneath your home. If this is not insulated, the energy from this radiation is soon lost. Traditional insulation materials will stop some cold and absorb the radiation heat. Isobooster insulation foil reflects the radiation heat, allowing you to make most of the ‘residual heat’ in a very natural way.
Physics (or rather, the world) is full of valuable and useful natural processes. A bit of knowledge and insight allows us to achieve maximum results with minimal means. As is so often the case, the smallest things hold the greatest power!