What does reflectance mean in the lighting industry?

What does reflectance mean in the lighting industry?

A common issue we encounter when doing layouts is how to accurately know what the reflectance is in a building. The reflectivity of the surface is calculated by a numerical value 0.0 behind jet black(no reflectance) and 1.0 being as white(full reflectivity). It does not go beyond these values. Typical default values are 0.8(ceiling) 0.5(walls) 0.2(floor) which is like a dark grey concrete floor. The ceiling plays a very smaller role in boosting the overall lighting while the floor and walls are the most crucial.

It makes a big deal to change this value when it is appropriate. One of the easiest ways to figure out the reflectance is to take a picture of the inside of a building. Try and include the floor and walls if possible, take several pictures if you can't get it all in. A nice shiny floor in a retail shop can up the default value to .6 in some stores, that is going to amplify your lighting tremendously. 

A warehouse is typically dirty and concrete floor so we often find these layouts require nothing more then a design. However, some concrete flooring is much lighter in some places, so keep that in mind.

 

scott