Daylighting, using natural instead of artificial, gives us the best quality of light with the lowest footprint. A hundred years ago there were all kinds of technologies to bring daylight deep into buildings, but they all were pitched in favour of the electric light. But as we noted a few weeks ago, in our post Daylighting Is Making a Comeback, computer controls are making it possible to deliver natural light that is controlled with the precision of artificial light.
Now Sun Central, a spinoff from the Structured Surface Physics lab of the University of British Columbia, has developed perhaps the most sophisticated daylighting system yet.
Why do we love daylighting so much? They explain at Suncentral:
Natural daylight is the perfect lighting solution for our living and working environments. The full and rich spectrum of natural sunlight provides a room with a look and feel that simply can't be matched by electrical lighting systems. The fact that we prefer natural light is not surprising as our visual systems were developed for a natural environment rather than the darker recesses of offices and other environments.
In the SunCentral system, the spandrel panel (the panel that covers the parts of a building between floors and windows) is replaced with an array of mirrors with computer controlled servos that track the sun. This technology has become so cheap that it is no more than a couple of bucks per unit.
this array then directs the light against two reflectors that concentrate it on another reflector, which shoots this concentrated beam down through the plenum (the space between a dropped ceiling and the floor above)
It then hits another reflector that bounces it down to a diffuser.
They did a test where they mounted the array on the outside of a building;
Installed a sort of light duct in the existing ceiling,
before and after
And you end up with as boring a dropped ceiling as you had before, except now it is daylight instead of fluorescent. And I suppose, from an engineering point of view, is what you want to be able to do. But I think the possibilities are much greater than that;
One could use the front end, the computerized array, to simply direct the light deep into the space like they used to do with prism glass;
Terry Thomas Building
And eliminate the drop ceiling, go back to the way they used to make the ceilings as high as possible, and just bounce the light around the place.
The inventors note that going through all of these complicated transitions of photovoltaic conversions to make electricity that is then used for lighting is just silly, when you can use the real thing. They list the benefits:
- Reduces energy for standard commercial building lighting by 25%;
- Replace electric lights for 6 of 8 hours in standard work day
- Peak demand reduction - coincides with grid peak power demand
- Provide useful direct daylight more than 20 metres into the building core;
- Outperforms photovoltaic-powered electric lighting by a ratio of 7:1
Whether one uses the entire system or just the front end array, natural light is free and healthier- a sort of computerized prism glass. What a wonderful idea. More at Suncentral Inc.