×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

White, white walls, ceiling, floor for lighting efficiency

White, white walls, ceiling, floor for lighting efficiency

White, white walls, ceiling, floor for lighting efficiency

(OP)
To light a building interior efficiently highly reflective walls are desired. I believe that newly painted white walls are only about 80% reflective to visible light - but this decreases as "dirt" accumulates on the surface.

What information is available on increasing the light level in a building independant of increasing the efficiency of the light source?






 

RE: White, white walls, ceiling, floor for lighting efficiency

Hello,

Light colored finishes are a prime source of reflected light and increase the useable light.  For the average light color pallette, we generally calculate it at 80%-walls, 60% ceiling, and 20%-floor reflectances.  We do include LDD, (Luminaire Dirt Depreciation), LLD, (Lamp Lumen Depreciations) and MF, (Maintenace Factor) that take into account the aging of the lighting system and the loss of reflectances and translucence of the lighting media.  That is why when we calculate the initial lighting levels, we are generally 30% to 40% above the maintained levels that are the targeted design levels.  That is also why we use dimming and switching to lower the lighting levels when a building is new.

The only other way to increase lighting levels is to select lighting sources that are of high efficacy, give good Lumen-Watt ratios and provide good color rendition indeces.

Windows and skylights at least in California also help, but we must use daylight harvesting controls, and they increase the heat load on the HVAC systems.

Hope that helps a bit.
Regards,
EEJaime

RE: White, white walls, ceiling, floor for lighting efficiency

I saw an interesting article about a homemade projector screen that used white latex paint with I belive silica sand applied to the surface. Google can probably help find it, has comparison pictures, big difference.

Doubt this will help you very much other than considering additives to the paint...

RE: White, white walls, ceiling, floor for lighting efficiency

OK.

But be aware that - commercially - I do not go to Target stores specifically because of their color scheme and harsh, glaring white lights off of their red and white contrasting decor.   

Tread carefully - There are reasonable causes to subdue lighting sometimes.    

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources