During a sunny day the walls of my house warm up (no surprise). My question: how much of this warming up (if any) comes from visible light? I associate infrared with thermal energy. If my house was floating in space (to prevent any thermal exchange with its surroundings) and I installed a giant infrared (and UV) filter between it and the sun, would it still warm up (compared to its rest temperature in full darkness)?
Thermodynamics – Does Visible Light Heat Things Up?
infrared-radiationsuntemperaturethermodynamicsvisible-light
Related Solutions
Given the same intensity or the same power density, the heating potential of all three LED's should be the same, since all energy radiated by the LED's will eventually turn into heat - it's just a matter of where the light radiated by the LED's will be absorbed.
There is no universal law saying that the absorbance for infrared light should be greater than the absorbance for visible light, so the outcome of experiments like yours, will depend on the absorption coefficients of irradiated objects with respect to specific wavelengths.
As an example, the graphs below (copied from this site) show the absorption coefficient spectrum for different skin components.
We can see that the absorption coefficient of water is increasing with the wavelength, while the absorption coefficient of melanin is decreasing.
So, what you've observed in the lab may say something about the light absorbance properties of the objects you've tested, but is not an indication that light with a longer wavelength produces more heat.
In a solid, "heat" consists of random vibrations of the atoms in that solid around their equilibrium positions. If the radiation striking that solid has a wavelength component that is close to one of those possible vibration modes, then the radiation will couple strongly with that vibratory mode and the solid will accept energy from the incident radiation and its temperature will rise.
If the incident radiation has too high a frequency (X-ray or gamma) the coupling is poor and the radiation just goes right through without interacting much. If the frequency is too low (radio frequencies lower than radar) the radiation bounces off and also doesn't interact much. This leaves certain specific frequency bands (like infrared and visible light wavelengths) where the interaction is strong.
Note that this picture is somewhat simplified in that there are frequency bands in the gigahertz range where the RF energy bounces off electrically conductive materials like metal (this gives us radar) but interacts strongly with dielectrics and materials containing water molecules (this gives us microwave ovens).
Note also as pointed out below by Frederic, molecules possess resonant modes that their constituent atoms do not and these can be excited by RF energy as well. Many of these molecular modes lie within the infrared range, giving rise to the field of IR spectroscopy.
Best Answer
Yes, it would, though not as quickly as if you were getting the full spectrum of sunlight. All frequencies of the light spectrum carry energy, so it becomes a question of how much of that energy is absorbed by the house.
For example, if your house was completely black, all that visible light energy would be absorbed by the house and converted into heat. If it was completely white (or massively reflective), there would be almost no heat transfer whatsoever.