White VS Aluminium Reflectors

Discussion in 'Lighting' started by keyaam, 2 Dec 2009.

  1. keyaam

    keyaam

    Joined:
    28 Jul 2008
    Posts:
    2,502
    Likes Received:
    16
    Location:
    Cape Town
    I spoke to a fellow reefer and advised me on rather painting my diy hood with white enamel as a reflector instead of using regular reflectors. I bought my lamps today and the agent also advised the same. Does white reflect light better than the aluminium we use as reflectors. I see Reefinmates does not add reflectors to there units and uses a white reflector.
     
  2. AdS Guest




    to hide all adverts.
  3. inflames

    inflames

    Joined:
    29 Oct 2008
    Posts:
    923
    Likes Received:
    9
    Location:
    Randparkridge (Johannesburg)
    I would say that there is no comparison between the 2. Yes white reflects, but a combination of the 2 would be good! I have done the DIY Hood and have painted it white and still use reflectors on my T5's!
     
  4. Junz

    Junz

    Joined:
    19 Dec 2008
    Posts:
    899
    Likes Received:
    2
    Location:
    Rustenburg
    i know you get different grades of aluminium reflectors IE : 60 ,70 , 80,99 % reflective.

    i assuming if you have a 80% or above reflective reflector it would be better than white paint.

    but thats just my opinion.
     
  5. schalkvj

    schalkvj

    Joined:
    3 Apr 2009
    Posts:
    53
    Likes Received:
    0
    Location:
    Johannesburg
  6. keyaam

    keyaam Thread Starter

    Joined:
    28 Jul 2008
    Posts:
    2,502
    Likes Received:
    16
    Location:
    Cape Town
    I think i got my answer. Thanks Schalk

    "A matt white painted surface, for instance, has a reflectance of 85% to 90% compared with only 60% specular reflectance from a polished stainless steel surface, while polished aluminium will be approximately 85%."
     
  7. Annoying

    Annoying

    Joined:
    14 Jun 2009
    Posts:
    2,107
    Likes Received:
    23
    Location:
    Port Elizabeth
    Never thaught that matt white had that power of reflection...
     
  8. Reef Inmate

    Reef Inmate

    Joined:
    14 Aug 2007
    Posts:
    190
    Likes Received:
    2
    Location:
    Amanzimtoti
    Some more info on Reflectance


    White Reflectance


    When light strikes an opaque surface, and by opaque we mean a surface that will not transmit light, some of the light is absorbed and some reflected. The ratio of the luminous flux reflected to the luminous flux received is known as reflectance.
    If a small element of the surface receives 100 lumens and reflects 70 lumens, then the reflectance is 0.7, or it can be expressed as a percentage as 70%. The remaining 0.3 or 30% would be absorbed.


    Diffuse Reflectance

    Different surfaces also reflect
    light in different ways. For example, surfaces such as paper, emulsion paint, carpets and so on, exhibit what we call matt or diffuse reflection, that is, the light reflected from the surface is scattered in all directions.


    Specular Reflection

    At the other extreme is mirror or specular reflection exhibited by shiny metal surfaces such as chrome, silver or pure aluminium.
    It is most important to realise that although specular reflections produce a clear image in the surface of the material, the actual amount of
    light reflected may be deceptively low.
    A matt
    white painted surface, for instance, has a reflectance of 85% to 90% compared with only 60% specular reflectance from a polished stainless steel surface, while polished aluminium will be approximately 85%.
    Mixed Reflection

    Many surfaces such as gloss paint, wood, plastic and so on, exhibit a combination of these two types of reflection.
    Gloss paint, for example scatters most of the light that it reflects, but also produces a specular reflection in the surface of the paint to 90% compared with only 60% specular reflectance from a polished stainless steel surface, while polished aluminium will be approximately 85%.


    Mixed Reflection

    Many surfaces such as gloss paint, wood, plastic and so on, exhibit a combination of these two types of reflection.
    Gloss paint, for example scatters most of the
    light that it reflects, but also produces a specular reflection in the surface of the paint.
     
  9. Pads

    Pads

    Joined:
    18 Aug 2008
    Posts:
    689
    Likes Received:
    4
    Location:
    Joburg, Bryanston
    Last edited: 2 Dec 2009
  10. Falcon

    Falcon

    Joined:
    26 Feb 2008
    Posts:
    2,869
    Likes Received:
    31
    Location:
    VEREENIGING
    I'm with junz on this...white may be better than a mirror or some galvanised sheeting etc but alanod etc comes in much higher reflectance values....

    i would never rate a white painted surface as over 80%(unless actually tested with a led and lumen meter) as remember all white paint is not the same.

    so yes HIGHLY REFLECTIVE ALUMINIUM remains the best reflectors hence all the big boys like geisemann and ati etc all use individual aluminium reflectors.

    now comparing a white painted hood to individual aluminuim reflectors you should loose about 15% light to the white paint and then a further 15-20% to not having individual reflectors.

    to put this into perspective a 54w t5 with a lumen output rated at 5000 lumens would give you a lowly 3500 lumen with white where as with individual highly reflective aluminium reflectors you'll get way over 4500 lumen...multiply by ten and a reef that had lighting set-up to deliver around 50000 lumen to the corals now only delivers around 35000 lumen to the corals,which is a huge difference!

    so for maximum efficiency go for individual Highly reflective aluminium reflectors.why have so efficeint lights if your not going to maximise them his goes to show that even t8 with the best reflectors will out do t5 with crappy reflectors.;)
     
Recent Posts

Loading...
Similar Threads - White Aluminium Reflectors Forum Date
Live rock changing white General Discussions and Advice 22 Nov 2016
Algae on white part of acropora SPS Corals 13 Sep 2016
Sps turning white SPS Corals 16 Aug 2016
white spot treatment that works Quarantine Tanks, sick fish, QT corals 13 Aug 2016
Urgent help needed cream angel white spot Urgent Help Needed 8 Aug 2016
My Regal Tang has white spots Quarantine Tanks, sick fish, QT corals 23 Jul 2016
White patch on clownfish Quarantine Tanks, sick fish, QT corals 23 Jul 2016