0
$\begingroup$

I'm reading the book: automating hydroponics, from Cerreto Rossouw.

He wrote, p46, "you shouldn't use aluminium foil because it's quite poor at reflecting light (...) A practical alternative (...) matte white paint, wich is 75-80 percent reflective"

well, I wonder why aluminium foil is poor at reflecting the light in comparaison of matte white paint. Is it the same for an aluminium mirror ?

$\endgroup$
  • $\begingroup$ the paint scatters the light so it gets spread nicely around the room. $\endgroup$ – PhysicsDave Mar 13 at 18:38
  • $\begingroup$ I think that the author means that matte white paint may be better as a diffuse reflector of light, which is the property of interest for this hydroponics application. A flat aluminum plate or foil is of course a better specular reflector of light than matte white paint surface is. $\endgroup$ – Samuel Weir Mar 13 at 21:36
  • $\begingroup$ your comments make sense $\endgroup$ – The Unholy Metal Machine Mar 15 at 16:12
1
$\begingroup$

The statement is untrue - aluminium reflects around 90% of the incident light.

The difference between aluminium and white paper is that aluminium is glossy and acts as a mirror. Therewith is "shows" the darker objects in the surrounding which may appear as being darker.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.