The University of Michigan (U-M) has adopted policies that limit purchases and upgrades of lighting systems to energy-efficient equipment. All U-M buildings use fluorescent lighting, because of their high efficiency in converting electrical energy to light.

The T-8 fluorescent lamp has been adopted by the U-M as its standard, replacing the T-12 lamp. When compared to the T-12s, the new standard T-8s use less energy and have the same lamp life.


Applicable Regulations
Under Federal Regulations adopted in 1992 as part of the "Federal Energy Act of 1992", no T-12 lamps were to be manufactured after October 1995.


Overview of Procedure
Lamps come in hundreds of different lengths and widths, but the most energy-efficient lamp is a T-8, which is a one-inch diameter tubular lamp. When compared to the past U-M standard T-12 lamps, the new standard T-8s use less energy and have the same lamp life. T-8 lamps are rated at 32 watts compared to the 40 watt rating of T-12 lamps, and yet provide the same level of illumination.

Coloration and chromaticity are two characteristics of concern when installing new fluorescent lamps in a work area. The ability of lamps to render colors is rated by illumination engineers using a Color Rendering Index (CRI). Under the CRI, a light source with a rating of 100 has the same color rendering ability as sunlight. The old T-12 lamps had a rating of 62; the light that they produced, while intense, did not have the characteristics of sunlight. The T-8 lamp has a CRI of 75, which is a 21 percent improvement over the old T-12s. This means that colors should appear truer to sunlight under the T-8 lamps.

Chromaticity refers to the pattern of visible wavelengths of light emitted by a bulb and is measured in degrees Kelvin (K). Most lamps fall in the range of 2200-7500K. A 2200K lamp creates a visually "warm" atmosphere that appears pink-red, while a 7500K lamp creates a "cooler" bluish tone. The T-8 lamp has a chromaticity of 3500K, which is considered to be visually "neutral," resulting in improved color rendering for most general office work.


Waste Minimization Procedure
Not applicable.


Known Limitations
The T-8 lamp is useful for most day-to-day office activities; however, they may not provide the highly accurate color rendering necessary for some specialized applications. "Full spectrum" lamps are defined as fluorescent lamps having a CRI of 90 or better and a color temperature of 5000K, designed to provide a completely balanced pattern of visible wavelengths of light.

Full spectrum lamps produce the most accurate colors; however, they are not "natural" in that they do not replicate natural sunlight or the normal conditions in which people view things. Full spectrum lamps are much costlier than regular lamps, and they require more electricity for a given level of light output.


Safety & Health Precautions/Personal Protective Equipment
None known.


Using the more energy efficient T-8 lamps in all buildings has resulted in electrical cost savings for lighting and conserves valuable resources. The T-8 lamps are rated at 32 watts; the older T-12 lamps were rated at 40 watts; this is a 20 percent energy savings. In addition, the new T-8 lamp provides a higher quality of illumi-nation than the T-12 lamp it replaces.


None known.


Project Related Costs
Information not available.