Reflectivity of ALuminium Foils

  • Thread starter RKD89
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    Aluminium
In summary, the thermal reflectivity of aluminium foil used at home is approximately 80-88% and it is commonly used as a solar reflector for its cost effectiveness. However, the slight crumbling of the foil can reduce its specular reflection and turn it into a diffuse reflecting surface. It is important to minimize crumbling if you want to direct the reflected light.
  • #1
RKD89
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1
Can Anyone tell me the exact THERMAL reflectivity if aluminium foils used at home?
 
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  • #2
Have you tried a google search?
 
  • #3
Why do you want to know?
 
  • #4
i am thinking abt using them for a solar reflector ( parabolic dish)
n I Tried googling....wiki says it's abt 80-88%
 
  • #5
RKD89 said:
i am thinking abt using them for a solar reflector ( parabolic dish)
n I Tried googling....wiki says it's abt 80-88%

That sounds about right. I doubt you can do better better for the cost. What you seem to be looking for is the "reflection spectrum" of aluminium, because the value depends on wavelength. By "thermal", you are practically referring to wavelengths that are greater than 800 nm (near to mid infrared).

The slighest crumble in the foil however will reduce the specular reflection. So if you want to direct the reflected light, you want to reduce crumbling to a minimum. Crumbling of foil turns it from a specular (mirror) reflecting surface to a diffuse (white) reflecting surface.
 
  • #6
Dr Lots-o'watts said:
That sounds about right. I doubt you can do better better for the cost. What you seem to be looking for is the "reflection spectrum" of aluminium, because the value depends on wavelength. By "thermal", you are practically referring to wavelengths that are greater than 800 nm (near to mid infrared).

The slighest crumble in the foil however will reduce the specular reflection. So if you want to direct the reflected light, you want to reduce crumbling to a minimum. Crumbling of foil turns it from a specular (mirror) reflecting surface to a diffuse (white) reflecting surface.


I have already tried d foil...works quite decent...
Of course the crumbling does result in some scattering...but in all it serves my applicaition
Thanx anyways
 

1. What is the purpose of using aluminium foil for reflection?

Aluminium foil is commonly used for its highly reflective properties. It is able to reflect up to 98% of light and is often used in various applications such as insulation, packaging, and as a reflective surface in optics and lighting.

2. How does the reflectivity of aluminium foil compare to other materials?

Aluminium foil has one of the highest reflectivity ratings among common materials, with only a few other metals surpassing it. For example, silver has a slightly higher reflectivity than aluminium, while gold has a significantly higher reflectivity but is much more expensive.

3. Can the reflectivity of aluminium foil be affected by its surface finish?

Yes, the surface finish of aluminium foil can affect its reflectivity. A smooth surface will have a higher reflectivity compared to a rough or dull surface. This is because a smooth surface allows for more efficient light reflection.

4. Are there any factors that can cause a decrease in the reflectivity of aluminium foil?

Yes, there are a few factors that can cause a decrease in the reflectivity of aluminium foil. These include oxidation, dirt or debris on the surface, and damage or tears to the foil. These factors can affect the smoothness and integrity of the foil's surface, reducing its ability to reflect light.

5. How is the reflectivity of aluminium foil measured?

The reflectivity of aluminium foil is typically measured using a spectrophotometer, which measures the amount of light reflected off the surface of the foil. The higher the reflectivity percentage, the more efficient the foil is at reflecting light.

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