Q: It used to be easy to replace a light bulb; now there are so many options, I don’t know what to choose. What do you recommend?
A: It’s hard to imagine a household commodity that has changed more in the last five years than the light bulb. The incandescent bulbs we all grew up with wasted a lot of energy and have been phased out. Government mandates ushered in the brief reign of the more efficient, but widely despised, compact fluorescent bulbs, or CFLs, which emit terrible-quality light and are difficult to dispose of because of their mercury content. The public’s loathing of CFLs accelerated the development of light-emitting-diode bulbs known as LEDs, which now rule the lighting world. These use up to 80 percent less energy than the old incandescents and can last for decades. LEDs are improving all the time and their prices are coming down. However, the quality of light they produce varies significantly, so it’s helpful to understand some lighting nomenclature before you buy.
Most LED bulb boxes have a Lighting Facts label that indicates brightness (measured in lumens), color temperature (labeled K for Kelvin temperature), energy use, estimated energy costs, and expected life. Since most packages also specify the type of incandescent bulb the LED replaces, you don’t need to pay much attention to the brightness measure. Instead, zero in on color temperature: 3,000K is my recommendation for a universally flattering, warm-white light. Anything higher is going to have a cooler, bluish-white cast. Another good measure is the Color Rendering Index, or CRI, which tells you how accurately the bulb renders colors compared to an incandescent bulb, which has a CRI of 100. For LEDs, a CRI of 80 or higher is best.
To ensure an LED will fit in your fixture, bring your old bulb with you to the store and compare the bases. The splayed fins that LEDs have to dissipate heat make them larger than other bulbs. Make sure the bulb is dimmable (you may need to replace your dimmer switches with LED-friendly ones to avoid annoying flickering or buzzing). And if you plan to use the bulb outdoors and/or in an enclosed fixture (some LEDs require more airflow than these lights provide), check that these applications are noted on the box.
If you haven’t already, now’s the time to embrace this new technology — unlike previous innovations, this one is here to stay.
Re-Printed From Residential Lighting Magazine November 2013 Issue
A Lighting Research Center study on lighting systems for Alzheimer’s patients could help an aging population.
Residential Lighting: Tell us how light levels affect circadian rhythms. (more…)
Circadian rhythms are internal biological rhythms that are controlled by an external factor which in most cases is daylight. Life on planet Earth has been affected by these circadian rhythms since life began. We are pre-programmed by hundreds of generations to be affected by the 24 hour day/night cycle of light and dark. We now have many sources of artificial light that we use every day. These sources of light are impacting our lives, specifically the quality and quantity of sleep we get.
Sunlight qualities changes as day progresses from sunrise to sunset. As sunlight travels through he atmosphere it is refracted and reflected. In the early morning there is more of the blue spectrum in sunlight and in the evening there is more red.
Melatonin is a chemical produced by the pineal gland in the center of the brain. It is necessary for sleep. Blue light suppresses melatonin production so exposure to blue light before bedtime interferes with a restful night’s sleep and disrupts the circadian rhythm. In nature there is less blue in evening sunlight and more in morning sunlight. That makes it easier to go to sleep in the evening and to get going in the morning.
What do we all do every evening at home…watch TV and plan video games on computers. TVs and other video screens emit light in the blue end of the spectrum. This causes low melatonin which results in sleep problems. And this is especially problematical for older people because as we age we produce less and less melatonin naturally. Maybe putting kids in front of the TV just before bedtime might not be a good idea!
More information will be forthcoming in future blog posts. In the meantime be sure to visit FoggLighting.com and like us on facebook.