Quote:
Originally Posted by CobraEd
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Ed,
I'm not sure what you're looking for, but I do have some comment.
I think there is some merit to these paints, but it is likely limited.
With all the energy talk, there is an increase in snake-
oil marketing too.
The idea is sound. Ceramic does not conduct (transfer) heat very rapidly and is similar to glass in this property.
An example is to consider college chemistry class where many of us learned to custom bend our own glass tubing to direct gases/vapors from heated solids/liquids. One may remember that it was easy to hold the melting glass tube fairly close to the part heated in the flame and still not burn our fingers. But, in contrast, if this was tried with metal rods, the rapid heat transfer would travel several inches very quickly and make a bare finger grip impossible. The difference is remarkable.
Because glass has this property, heat
conduction loss through glass windows is far less than one might originally presume. But another helpful property of common glass is that it does transmit most of the visible light spectrum quite easily, but does not
transmit infrared (heat) frequency as easily. E-glass modification is a further play enhancement on this property.
Since visible light can easily come through glass, such as the visible sunlight spectrum, light comes in, but can't ordinarily reflect back out. This is because when light, which is a higher frequency, strikes a surface (especially dark colored), it loses energy, particularily in the form of frequency, which, in turn, causes the light radiation to drop to a lower frequency.
The lower frequency is, of course, that of infrared. So the light is turned to heat; and then cannot easily escape back out the window because glass does not freely transmit infrared like it does higher frequency visible light. The pass/block effect is comparable to opaque solids which do not transmit visable light but allow even higher frequency radiation, such as x-ray, to pass barely impeded. If the reflection were reduced to visible light, the opaqueness would block it.
You can actually demonstrate this effect to yourself by building a nice fire in your fireplace. Move in close with your sensitive face so you can feel the heat on your skin. Then pass a small window pane between the fire and your face. The immediate drop in heat radiation can be felt. The glass casts a "shadow". This is also the principle in which atmospheric "greenhouse gases" operate.
So what does all this mean concerning ceramic paint? I think it works, but the pane is pretty thin. Any hollow spheres would be a big plus. There may be data confirming significantly better heat blocking by ceramic than that of glass, I don't know. Glass is sort of a transparent ceramic when you think about it.
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You might enjoy this
link concerning maximum home insulation. It is apparently possible to build a home so carefully that it requires no heat source at all, even in the far north.
The first Saskatoon'ers were actually built in the late '70's, but I couldn't find a link. Back then, the inspiration was caused by the first energy crunch in 1974, also giving us the hated 55 mph law.
Wes
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Ceramic insulating wall paint
Linear Mode
