How Is Fluorescent Light Different From Natural & Artificial Light?

Energy Use

• Fluorescent lights are more expensive and more energy-efficient than incandescent bulbs. Energy Star-qualified compact fluorescent lights, which have a distinctive spiral shape, use about one-fourth the energy and last 10 times longer than a bulb that puts out the same amount of light.

  Incandescent bulbs are inexpensive to produce but expensive to use; Energy Star estimates that such energy-inefficient lighting eats up about 10 percent of a house's electricity. What's more, up to 90 percent of the electricity consumed by incandescent lights is turned into heat, not light.

  Natural light comes from the sun, so it's free, and it reduces the need for artificial lighting, so it helps cut lighting costs and save energy resources.

Light Quality

• CFLs are miniature versions of full-sized fluorescents but screw into standard lamp sockets and give off light that looks like the old-fashioned incandescent bulb. Fluorescent light has no filament but rather is created by gas, so it varies more than incandescent light. CFL bulbs come in cool and warm whites with tones from blue-white to yellow-white.

  Incandescent bulbs have filaments that glow at nearly constant brightness; the power does ripple, but it is not visible to the naked eye.

  Natural light is steady because its source, the sun, is steady. Natural light also can come into a room without glare via skylights and sun tubes.

Health Effects

• According to Energy Star, research shows that "day lighting," as the use of natural light is referred to, saves money and improves productivity. Multiple health benefits are attributed to exposure to natural sunlight, including the body's production of vitamin D.

  Fluorescent lights appear steady but blink on and off at a rate of 60 times a second; some people believe this causes headaches. The mercury in CFLs is a neurotoxin; the bulbs also emit UV rays. Fluorescents have been linked to chronic illnesses.

Post-Consumer Waste

• No bulb, no trash. Natural light has no waste associated with it.

  Incandescent bulbs can be tossed in the trash.

  Fluorescent bulbs contain a small amount of mercury and should be recycled when they burn out. Many stores that sell CFLs also accepted the used bulbs for recycling.