Let’s start in the garden. We know that light from LEDs grows plants quicker and healthier than other methods, including natural sunlight. Sunlight contains the full spectrum of colors, giving plants the information needed to grow. Tinkering with this spectrum, which LED lights allow with precision, elicits known and specific responses. Increase the amount of red, yellow, orange and green, and plants grow taller. Add blue or other UV colors and they grow more compactly.
The ability to manage the spectrum of light with intent and purpose is a powerful position that makes strategic and fiscal sense in the world of apartment features. Just as light affects how plants grow, science is discovering a similar relationship to human health. Building this knowledge into common areas, even units, is an especially low-to-no-cost option to make residents feel better, sleep better and know that they are conserving energy at the same time.
LED lights will also be a major component of the smart apartment of the future.
Light and its part in human health
The CRI (Color Rendering Index) is the quantitative measure of light and its effect on human perception. The standard deals with light, illumination, color and color spaces. Specifically, CRI determines how natural the color of objects appears under various lighting. Natural, in this case, means as things appear under color free light (such as sunlight which scores a perfect 100) making it possible for the human eye to identify all colors and shades of an object. Other than sunlight, incandescent bulbs are the only other light source that scores 100, which may explain the market’s resistance to their phase-out.
Poor lighting, especially lighting with values below CRI 50, is associated with eyestrain, migraines, depression and more. Simply put, poor lighting does not portray objects in their true color. One extreme example is the High Pressure Sodium (HPS) streetlights, which at 25 CRI, makes everything appear yellow.
A more complete color spectrum—one that contains more colors and more closely emulates sunlight—offers the best indoor human environment, resulting in specific health benefits. Such lighting is often packaged as “full,” “wide” or “continuous,” but terms vary by manufacturer. Basically, trust your own eyes. If the light looks strange to the human eye, is overly sharp and makes things look inorganic, it has a low CRI value and is probably the result of a simple red-blue LED chip combination.
Artificial light optimized for humans
Unlike incandescent or fluorescent light, LEDs emit light at specific wavelengths. Certain blue wavelengths of light are known to depress the body’s production of the hormone melatonin. In nature, the highest level of blue wavelength light reaches the earth’s surface in the middle of the day and causes individuals to be more alert. Conversely, warmer light in the evening helps a person wind down, helping to normalize his circadian rhythms and eventually allows restful sleep.
Highly-tuned LED lights are an effective substitute when natural sunlight is insufficient. Human Centric Lighting (HCL) extends beyond simple LED lighting to the health benefits of exposing individuals to variable wavelengths of light throughout the day in order to modulate mood-altering melatonin levels. Because of their ability to generate highly tuned wavelengths, LED lights are ideal for HCL applications, including treating those who suffer from seasonal affective disorder (SAD), depression or anxiety disorders. For the general population, research by A.T. Kearney found evidence that HCL improves concentration, boosts energy and improves the overall feeling of well-being. Such benefits would be a boost to any apartment community, and would certainly be a competitive edge.
Reducing the cost of operation
Operationally, many LED lights on the market today generate the same or better illumination as incandescent bulbs with 50 percent less energy input. LEDs’ increased efficiency is due, in large part, to the bulb’s energy being utilized to produce light rather than wasteful heat. They last, on average, 40,000 hours compared to incandescent bulbs, which burn out in approximately 1,000 hours. This makes the lifespan of 40 incandescent bulbs equivalent to the longevity of one LED, making the higher (but dramatically falling) upfront cost quickly recoverable.
To minimize energy consumption, any lighting project should include turning the lights off, as well as reducing wattage when the lighting is on. The most cost-effective solution is to add occupancy sensors or basic timers to the light controls in order to reduce the load to zero whenever possible. In restrooms, storage areas and common areas, a simple, inexpensive commercial sensor can easily reduce lighting cost by as much as 70 to 90 percent. Public spaces, stairwells and parking garages are areas that may be lit regardless of occupancy because of safety concerns.
Upgrades to lighting should also include improved fixtures and ballasts that contribute to lower maintenance cost. If fixtures are also being replaced, consider fixtures that allow easy access to the lamp during replacement. Quick connect wiring plugs permit faster and safer installation and maintenance, and sealed housings prevent dirt build-up and corrosion in humid environments. These are just some examples of features that can reduce or even eliminate the need for costly maintenance.
Replacing incandescent, halogen and High-Intensity Discharge (HID) lighting with LED equivalents can also greatly reduce the cooling load. Locations with warmer climates will benefit more from cooler lighting, with savings as high as 1kWh in cooling for every 3kWh reduction in lighting.
All in all, the EPA (Environmental Protection Agency) has calculated that LED lights will save 88 terawatt-hours of electricity from 2010 through 2030—enough to power seven million homes for a year and save around 5 million tons of carbon dioxide annually. LEDs are manufactured with no hazardous materials and can be discarded with no concern about adding hazardous materials to landfills.
LED lights are a rapidly evolving technology that have grown even more energy and cost efficient in a few short years. As engineers and manufacturers hone in on processes, it won’t be long before LEDs are a must-have feature of every apartment home.
Resources: Pacific Northwest National Lab, U.S. EPA, National Institutes of Health, Illuminating Engineering Society of North America (IESNA), International Commission on Illumination (CIE) publishes the Color Rendering Index (CRI), Department of Energy.