Full Spectrum Fluorescent Lamps

Summary

The flickering, blue-greenish hue is bad enough in the office, they say. The residential market has been slow to embrace fluorescent lighting for several reasons. For one, the lighting quality has been associated with a feeling of institutional coldness. As it becomes more accepted that lighting quality approaching daylight enhances health and well-being, manufacturers are introducing improved fluorescent products that recognize the role of the Color Rendition Index (CRI) and Kelvin temperatures in achieving comfortable lighting.

Details

A so-called "full spectrum" fluorescent system typically consists of: an electronic ballast, control wiring, power wiring, a wallbox switch and fixtures with full spectrum fluorescent lamps. Most of the large lamp manufacturers offer fluorescent lamps with the high CRI and moderate temperature associated with pleasant residential lighting applications. However, they will usually say they do not offer residential full spectrum lighting. Full spectrum flourescent lighting is available only in tube configuration. Several manufacturers are introducing screw-in compact fluorescent lamps with CRIs over 90.

"Full spectrum" lighting is variously defined, but the type of residential fluorescent lighting generally associated with qualities similar to incandescent has a high CRI, hence the "full spectrum", with a moderate Kelvin temperature (2700 to 3500) to emphasize warm colors. Actual full spectrum lighting has both a high CRI (90 to 100) and a high Kelvin temperature (about 5000 to 6000) with a ratio of visible spectrum to ultraviolet wavelengths that replicate noontime daylight.

The lighting quality of a fluorescent lamp depends on the combination of chemical phosphors used. The two main types of phosphors are halophosphate, for warm and cool white lamps, and triphosphate which contains one phosphate for each primary color. These are mixed in the proportions necessary to achieve the high CRI associated with full spectrum fluorescent lighting. Triphosphate fluorescent lamps can be tuned to vary color output across the spectral range, by adjusting the type and amount of phosphors within.

Installation

Full spectrum fluorescent lamps work with the same ballasts and wiring that ordinary fluorescents do. The compact fluorescent lamps may be self-ballasted. For other lamps, ballasts can be bought separately to be used with full spectrum lamps, or purchased as a system. And like ordinary fluorescents, ballasts can be mounted in various places but it is best to keep the wiring runs short.

Benefits/Costs

Full spectrum fluorescents are usually at least twice the cost of quality cool white fluorescent lamps. But because the light is pleasant enough to replace incandescent lighting, savings can eventually be recouped in lower electric bills and fewer bulb changes, depending on the frequency of switching. Photosensors, occupancy sensors and/or time clocks can also be used to further increase energy savings.

Limitations

Because of the cost of the technology, there has not been much of a manufacturer incentive for marketing full spectrum fluorescent lamps for residential use. Marketing has been driven more by the need for high-quality, high-efficiency lighting for commercial/industrial applications, and bright, full spectrum lighting for Seasonal Affective Disorder.

Compact fluorescent lamps emit electromagnetic frequency wavelengths, which can interfere with household signals such as television and radio. For this reason manufacturers recommend positioning these lamps at least eight feet away from such devices. There has been concern that the disposal of fluorescent components may allow toxic chemicals into our environment. PCBs are associated primarily with magnetic ballasts, but all fluorescent lamps contain mercury. Alternatives include low-mercury lamps and lamp recycling.

Code/Regulatory

Check with the local utility or manufacturer for rebate or credit programs that still may be available.

Availability

Widespread.

Contact(s)

Do you have a specific question about this technology and/or its 'real life' applications? Try the contacts listed below:

Illumination Engineering Society, IESNA
120 Wall Street, 17th Floor
New York, NY 10005
(212) 248-5000

Lighting Research Center
Rensselaer Polytechnic Institute
Troy, NY 12180-3590
(518) 276-6000
fax: (518) 276-2999

Environmental Protection Agency Green Lights Program

Lumichrome by Spectra-Tech Inc.
P.O. Box 65217
Baltimore MD 21209
888-385-6850
http://www.spectrat.com

Vita-Lite by Duro-Test
9 Law Drive Fairfield, NJ 07004 800-289-3876
http://www.durotest.com