Brenco Energy Concepts is an innovative, progressive organization with a very high degree of environmental awareness. We sincerely believe that by offering products designed to operate in an energy-efficient manner both the company and the planet will benefit. With this forward-thinking philosophy as a basis, and with the technical expertise available to us, we feel it is our duty to bring to the public’s attention any products or services that contribute to waste and pollution.
The subject of this report concerns the performance of specific light-emitting-diode (LED) lighting fixtures recently observed in a commercial parking garage. The subject fixture is a metal housing of four sides with approximately two dozen individual LEDs per side, or about 100 lamps per fixture. The large array of heat sinks fashioned into the rather bulky housing indicates the presence of excessive heat being generated by the circuitry associated with this multiple-LED configuration.
The high degree of glare produced by this unit makes this a visually offensive light fixture, one that should not be used in a public area or in any locality where aesthetics are important. In an attempt to stretch the limited capabilities of LED technology the design of this product creates excessive light pollution beyond any reasonable limits.
Measurements: Illumination level at the floor, directly below the fixture is 19 footcandles (fc.) Measured 42 inches above the floor, or approximately 4 1/2 feet below the bottom of the fixture, the illuminance shows a high of 60 fc in the center of the parking space and drops rapidly to only 3fc at the opposite side of the adjacent space 14 feet away, or halfway to the next fixture. This is a max/min ratio of 20:1. Nationally recommended standards established for parking garages by the Illumination Engineering Society (IES) show a ratio of 10:1, so this unit falls outside recommended levels. This illustrates the fact that LED units in general tend to be overly bright near the fixture with rapid light falloff near the edges of the area under consideration. Except for the glare, overall illumination levels within the parking spaces are satisfactory.
Although these lights do provide illumination for safety and security within the parking areas, this is done in such a manner as to produce a highly objectionable amount of glare into the eyes of the observer, causing momentary blindness as well as light spillage onto adjacent properties. In order to cover a wide area, each of the 4 faces acts as a wall of glaring light directed at the eyes of the observer. (If properly shielded the only light would be straight downward since LEDs by design are highly directional.) The resulting vivid glare is the equivalent of looking directly into a high intensity discharge (HID) lamp, such as metal halide. In fact it produces more glare-generated visual distraction than looking at HID because there you see only one high intensity specular light source where the electric arc is produced, whereas with the LED unit you are looking directly into the business end of more than two dozen high output LEDs. This high degree of horizontal glare, with absolutely no attempt to shield the light source, produces a number of potentially serious issues:
- Where observed, these fixtures were relatively low (8 to 8 ½ feet above the pavement) and therefore the glare may potentially and temporarily inhibit a driver’s sight. In our opinion, this may cause vehicles backing out of parking spaces and into active traffic lanes to be struck. For the same reason it is entirely possible that a pedestrian walking to his or her car may be struck by a moving vehicle where the driver cannot see due to the glare.
- In our opinion, it may also be possible that momentary blindness due to glare could prevent a person from observing a potential attacker or predator in the vicinity prior to entering the vehicle.
- The production of glare at or near the horizontal plane means that much of the light is wasted and not actually used to light the parking places. So in our opinion this particular LED fixture in use is not actually “green” after all. From an energy use standpoint, light being produced and wasted in this manner is in the same wasteful category as the generation of heat (instead of light) by incandescent and HID lamps. So any mention of energy efficiency in relation to this LED fixture is “greenwashing” in the extreme.
- Since most of the parking levels are above ground and there are no solid walls, the glare from these units is visible to the public on streets and walkways outside the building. Today, many states and communities are passing and enforcing so-called light pollution ordinances to limit the amount of light spillage on to adjoining properties. Therefore it is recommended that consumers check local ordinances before pursuing any lighting project.
As a public service, Brenco Energy Concepts and other leaders in the field of environmentally conscious organizations need to continue informing residents, governmental officials, and corporate decision-makers of the vast amount of misinformation being distributed regarding LED lights. There are some good LED products on the market that are designed to operate within the limitations of the technology, and when properly designed and applied the results can be satisfactory. However, in applications such as parking garage illumination, there are other high technology products readily available, such as induction lighting, that produce more light per watt of energy, are free from light pollution and glare, and cost much less than comparable LED units.
As professionals in the lighting field, we strongly believe that when all the facts are laid out and presented in an intelligent manner, the intelligent consumer will see that presently LED lighting does not yet provide the most effective lighting solution or the best cost benefit when compared to other lighting resources and in fact may lead to other long term challenges for the end user.
