Daylighting Made Simple: How EVERYONE Can Benefit From Solar Shades


Daylighting sun and clouds

Daylighting is nothing new. For centuries, builders all over the globe have known that placing windows on one side of a building versus another made for a far more comfortable home that required fewer resources to keep warm and illuminated. A lot of us may tend to shy away from the science surrounding solar screen shades, after all, the complexities and time requirements of everyday life can leave us with little extra bandwidth. But, even a little understanding of concepts such as daylighting can make the argument for solar shades so much more compelling, so your return on investment could really make it worth your while.

So let’s start out simple- according to Wikipedia:

“Daylighting is the practice of placing windows or other openings and reflective surfaces so that during the day natural light provides effective internal lighting.” View entire article.

Basically, daylighting boils down to taking optimal advantage of natural daylight to reduce the need for artificial lighting. It’s relatively easy to just put a lot of windows in a building’s design, focusing on the equatorial side of the building (so for us in the US, that would be south), and limiting windows on the polar side of the building (US-north) where less light would enter and more energy could be lost. The downside is that these windows will sometimes make it too bright, and often too hot for comfort. There are certainly various architectural ways of decreasing this problem, but most of those design ideas limit the view of occupants to some degree. That’s the tipping point for solar screen shades.

Solar Shades Really Do Block the Sun, Not the View

On their own, solar screen shades can increase the visual and thermal comfort of a room dramatically. The scientifically designed fabrics rely on several properties for their effectiveness, including the weave style and openness, the color and the materials that make up the yarns themselves. Some high performance fabrics like SilverScreen and EnviroScreen have a highly reflective, fine layer of aluminum on the back side of the fabric. Other technologies, such as KOOLBLACK by Mermet decrease the amount of near infrared solar radiation that passes through the fabric. The basic idea remains the same, though: stop a great deal of the heat and excessive light that pass through the solar fabric, leaving the room with comfortable light levels and managing heat. The big bonus, and by “big” I mean “huge”, is that the lowered amount of light coming into the room along with the open spaces in the fabric allows the occupant to see out. Boom! Anybody who’s ever put on a pair of sunglasses knows that when you limit the amount of glare, colors come back to life, and comfort ensues.

Combining Solar Shades & Automatic Control: Something Close to Magic

Increased comfort and energy efficiency are a given when it comes to solar screen shades. When you add automatic control or building automation to the equation, you get, well, I already said it- something close to magic. Opening and closing shades at just the right time of day, by just the right amount, and accounting for the season and the angle of the sun in the sky optimizes the energy savings and visual comfort in a building, and therefore increases satisfaction levels, health and productivity of the occupants. A visual connection to the outside no matter what the shade’s position enhances those benefits further still, and that’s where the magic comes in. The common name for it is “daylight harvesting”, but I think “magic” has more pizazz! Maybe “building solar alchemy”… ???… okay, probably not.

Here’s a simulated example that nicely illustrates how the daylight in a room changes throughout a given day. See how the combination of natural daylight and the reflective light off of the adjacent building makes the room practically unbearable at 0:08? Even the surfaces of the room are taken into account by the IES VE Radiance software that created the simulation. This technology is being used today to design more efficient buildings, and adds even more opportunity in the solar shade industry. Don’t get left behind! How would you address the needs of this room with solar screen shades and fabrics?

If you REALLY want to get your geek on, check out this explanation of how the “daylight factor” in a space is calculated (source: Wikipedia England), which accounts for direct light from the sky, reflected exterior light, and reflected interior light.

The more you know, the more opportunities you can create.