Wall washing can be an extremely usefull lighting techique. It will help open up the space and create a "natural light window" depending on wall color. It can also be used to "draw" people into a space, such as retail. Tests have shown that humans are drawned to the brightest location in a space. By wall washing the back of a retail store your customer will be drawn to the back of the store, making impulse purchases along the way!
The Aspect 5 by Omega Lighting offers this technique in a very efficient manner (over 92%) and with a fixture height of 2 1/8 inches, it will fit in the smallest of plenum spaces....
http://www.omegalighting.com/pdfspecs/RV1-47.pdf
Wall washing, the other "indirect lighting" option
