In Perpetual Noon: Fluorescent Lighting and the Modern Office, Margaret Maile writes about lighting design in offices of the sixties:
Far from being perceived as a necessary evil, the artificial environment of the mid-century corporate office was praised and celebrated for its stability. It removed the imperfections and fluctuations of natural systems and allowed a constant controllable set of environmental conditions. Electric lighting contributed significantly to the constantly of the mid-century office environment. it was argued that when correctly designed, electric light could effectively simulate and even improve upon, the qualities of natural light.
Things have changed since then; we no longer design luminous ceilings with wall to wall fluorescents. Architects try to give people a bit of natural light. Suspended ceilings are no longer universal as designers aim for higher ceilings. And most importantly, fluorescent bulbs are being replaced by LEDs.
But it's not just a matter of changing a bulb; you can do that, but LEDs create the opportunity to design new kinds of fixtures. CREE has just introduced a new fixture for office use, the LN suspended luminaire, that takes advantage of the strengths of LEDs, being a point source instead of a big tube. They call it WaveMax technology; It aims the light into a wave guide, bouncing it along with total internal reflection until it hits the "Diamond facet optical elements" that distribute the light, 60 percent up to bounce off the ceiling, 40 percent down.
It's efficient light, with 105 lumens per watt, and high quality light, with a color rendering index of 90+ (an incandescent bulb is 100, a typical fluorescent is anywhere from 50 to 85 depending on how much you are willing to spend). But perhaps most importantly they are dimmable down to 5 percent. This is important as designers start maximizing natural light and dimming down the artificial light to save energy and improve the quality and color temperature of light so that it does not feel like perpetual noon.
It's also a smart looking design, with the wave-guiding wings cantilevering off a cast central beam that encloses the bulb, and snaps neatly into the next fixture. Combined with their wireless controls, Cree claims it will let users "experience intelligent light at an affordable price, creating a customizable lighting environment that can save more than 70 percent in energy costs over outdated linear fluorescent lighting."
It's easy just to pop an LED tube into a fluorescent fixture, just like people are doing everywhere with LED bulbs into fixtures designed for incandescent bulbs. But LEDs are a different kind of light. Now we are beginning to see what they can do when the fixtures are actually designed for them. it is an important trend.