Green Product Category: Lighting

Lighting is a major user of electricity. It also generates heat, contributing to cooling loads that are generally met by using more electricity for air conditioning. Thus, improving the energy efficiency of lighting has benefits that go beyond the direct electricity savings by the lighting products.

Fluorescent lamps are three to four times more efficient than incandescent lamps. Quality fluorescent lamps today provide far better light quality than the older lamps that often produced a bluish cast. Electronically ballasted fluorescent lighting also doesn’t generate the hum and flicker that many people find objectionable in older, magnetically ballasted fluorescent lighting. Both straight-tube fluorescent and compact-fluorescent lamps (CFLs) are widely available. In general, thinner-diameter fluorescent lamps offer higher efficacy (lumens per watt) than larger-diameter lamps.

LED (light-emitting diode) light sources are also being introduced and are approaching the efficacy of fluorescent lamps. The highly focusable nature of LEDs enables significant energy savings in certain applications. Unlike fluorescent, metal halide, sodium, and other high-intensity discharge (HID) lamps, LEDs do not contain mercury.

Older magnetic ballasts for fluorescent lighting may contain highly toxic PCBs or the less toxic but also problematic DEHP, which is often used as a softener in PVC plastics. These ballasts should be handled carefully and disposed of properly when changing or servicing fixtures. Fluorescent lamps (as well as all HID lamps) also contain small amounts of the toxic metal mercury. These lamps should never be landfilled or incinerated but instead be recycled by a company that reclaims the mercury. Some new lamps are available with mercury levels far below the industry average, and these should be used whenever possible.

Daylighting

Daylighting strategies must be carefully designed if they’re to result in net energy savings. In commercial buildings, savings often don’t accrue unless there are automatic controls. But in homes, those controls may not be as necessary to achieve savings. Daylight also introduces heat that can increase cooling loads (though daylight’s ratio of heat to light is less than that of all common artificial light sources). Daylight can also cause problems with glare. In spite of these potential pitfalls, daylighting is a valuable strategy for saving energy and improving the well-being of occupants.