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ALTERNATIVE LIGHTING SYSTEMS
Summary:
Upgrading or installing fluorescent lighting systems is but one means for conserving energy. Other types of energy efficient lighting fixtures, appropriate for certain applications and implemented at the University of Michigan (U-M) where feasible, include compact fluorescent lamps, halogen lamps, and high intensity discharge lighting (HID).

 

Applicable Regulations
None.

 

Overview of Procedure
Compact Fluorescent Lamps:
A compact fluorescent lamp provides the benefits of fluorescent illumination in a device that can be installed in the screw-in sockets typically used on incandescent lamps. If an office or work area is equipped with small incandescent lamps, it is more efficient to replace the fixtures with compact fluorescent lamps.

Halogen Lamps:
Halogen lamps are used in applications such as: floodlighting, display and accent lighting, and automobile headlighting. Even more efficient than halogen lamps are Halogen-IR (HIR) lamps. The HIR lamps trap invisible infrared spectra and redirect them to produce more visible light. The result is a more than 40 percent efficiency gain over standard halogens, while providing the same amount of light output, beam control, and compactness as the standard halogen. HIR lamps have a color temperature of 2700-3000K while providing a Color Rendering Index (CRI) greater than 96. Refer to the information guide in this manual titled "High Efficiency T-8 Fluorescent Lamps" for a more complete description of CRI and color temperature (chromaticity).

High Intensity Discharge Lighting (HID):
Discharge lamps use ballasts to produce light by passing an electric current through a vapor or gas inside the bulb, rather than through a tungsten wire. HID lamps include groups of lamps known as mercury vapor, metal halide (MH), and high pressure sodium (HPS). All three lamps can be used for street or parking lot floodlighting and industrial or commercial applications, gymnasiums and rooms with high ceilings, as well as retail merchandise displays. Some models can also be used in office or classroom applications.

The MH and HPS lamps are more efficient, may have better color rendition than the mercury vapor lamps, and can produce over 60 percent more lumens than a mercury vapor lamp of the same wattage. Also, at the end of the average rated life, a mercury vapor lamp will have dropped down to less than 45 percent of its initial lumens, while the MH and HPS lamps will only have dropped to 65 percent and 80 percent, respectively. Due to the drawbacks stated, U-M no longer uses mercury vapor lamps.

 

Waste Minimization Procedure
Not applicable.

 

Known Limitations
Compact Fluorescent Lamps:
Compact fluorescent lamps are incompatible with circuits that dim lights, do not immediately go to full brightness when switched on, and take about 2 - 5 minutes to reach full intensity.

Halogen Lamps:
Unlike the compact fluorescent lamps, halogens can be used in dimming circuits. Halogen lamps may experience bulb blackening due to frequent dimming. This problem can be easily remedied by leaving the lamp on at full brightness for about eight hours.

High Intensity Discharge Lighting:
None known.

 

Safety & Health Precautions/Personal Protective Equipment
Follow all applicable safety and health protocols and regulations as established by your institution.

 

Benefits
Compact Fluorescent Lamps:
Compact fluorescent lamps can be as much as 80 percent more efficient and last more than 10 times longer than filament lamps. For example, a 26 watt compact fluorescent lamp can replace a 100 watt incandescent lamp for a savings of 75 percent. Compact fluorescent lamps have an average CRI of 82 and come in a wide range of color temperatures (chromaticity).

Halogen Lamps:
When compared to conventional type incandescent lamps, tungsten halogen lamps have a longer life, higher efficiency, and compact size.

High Intensity Discharge Lighting:
HID lamps are among the most efficient and long-lived lamps available, providing a long lamp life (approximately 10,000 - 25,000 hr.), high light output, and can cover large areas. HID lamps are a good choice for industrial, commercial, and floodlighting applications.

 

Disadvantages
Compact Fluorescent Lamps:

None known.

Halogen Lamps:
More expensive than conventional lamps.

Note: U-M Housing policy states that 300 watt or greater halogen bulbs are not allowed in dormitory rooms due to the potential risk of fire.

High Intensity Discharge Lighting:
This type of lighting can produce strobe effects around moving machinery and can also present ultraviolet exposure concerns if the shielding breaks.

 

Project Related Costs
The U-M Plant Department has undertaken an ambitious program to upgrade many lighting systems to operate more efficiently. Alternative lighting systems are one part of the program. The entire lighting system upgrade program resulted in a cost savings of $201,145 for fiscal year 1996. Lighting retrofits that have been underway since 1988 have resulted in cost savings in excess of $1.6 million.

 

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