Too Much of a Good Thing – How to Reduce Light Pollution Around Commercial Exteriors
Do you remember star gazing as a child? When’s the last time you could do that? Maybe it’s just been pushed down on the list of priorities or maybe when you look up, there’s not much to see anymore. The stars didn’t disappear, but true darkness around commercial exteriors, and especially urban centers, has become a thing of the past.
Nighttime light pollution, or sky glow, is the combined light from streetlights, parking lots, malls, office buildings, stadiums, and other structures that brighten the night skies. It occurs when poorly designed light fixtures project or reflect light upwards instead of at their designated targets. While not a huge complaint on the spectrum of societal issues, this shift from dark to light is not without its costs.
LED Outdoor Use in the Past
It’s quite common to replace outdated high-pressure sodium lights with energy efficient blue-white LEDs, but initially, the differences between both light sources were extreme and in some cases, detrimental. From a cost and efficiency standpoint, it makes sense to make the switch to LEDs. Although there is a higher upfront cost, the bulbs last much longer, use a fraction of the energy compared to incandescent and sodium lighting, and don’t contain materials like mercury – common in fluorescent lighting – that can harm the environment.
At first, LED lights were housed in the same fixtures the older, high-pressure sodium bulbs had been housed in, without thought to the extreme illumination difference. LED lamps are much brighter than their predecessors and light spilled out and around the lamp housing. This caused light pollution and it was quickly realized that simply blocking light from going directly upward was not enough. In addition, many high efficiency LEDs emit a blue-white light that tends to increase the amount of glare sensed by the human eye and the amount of visible light pollution.
LED Outdoor Use Now
Now, LEDs have become a much more accepted exterior lighting source for the following reasons:
Lighting experts have developed a three-part lighting fixture to focus light rays parallel to one another. These parallel rays ensure that the light is directed at the desired area, rather than trespassing into other spaces.
Dimming and sensor capabilities
By combining LED bulbs with occupancy sensors that turn on and off in response to movement, areas are illuminated only when needed. In areas that experience reduced traffic, also consider adaptive lighting, a technology that reduces light levels at certain times of night when the area is unused.
The right light with the right angle
Lighting designers can select LED lights with the correct beam angle encased above and to the sides. This helps to channel the light downward and reduce the amount of light pollution taking place. Known as ‘cutting off light at the horizontal’, this ensures that light is used to illuminate the ground only.
To reduce light pollution, instead of selecting LED bulbs with a strong blue-white light, look for LEDs with a warmer, white illumination –those with a color temperature of 4000K or less.
To combat lighting pollution, discuss all lighting design options with a contractor prior to retrofitting old fixtures or during a new build. Be considerate of neighboring businesses and residences by understanding what fixture and LED bulb is appropriate for your building before moving forward with an installation.