I read an article today about how UPS has covered some of their trucks with frosted glass to allow drivers to see and find their packages with greater ease. However, one of the drivers noted the temperatures in the truck (due to inadequate ventilation, I suspect) rise quickly and stay at temperatures well over 110 to 130 degrees.
Is it impossible to create glass which could allow visible light but not allow the wavelengths associated with infrared light, which heats the interior of spaces with lots of glass and no ventilation (like our cars during summer)?
Or is this process more complex than I am thinking? If not, why not?
Best Answer
Visible light carries heat as well.
Regular windows actually are somewhat translucent in the infrared spectrum (I think they are almost opaque in IR).
The visible light can heat up objects in the truck; and those objects would emit IR radiation, which would actually make it very warm, as the IR would not be able to escape. I feel like that is what may be happening here; the trucks heat up because this glass does block IR; allowing all the black body radiation from the packages to remain trapped in the truck.