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Conserving Energy Through Lighting Maintenance

Lighting maintenance is much more than just replacing burnt-out bulbs. Effective lighting maintenance includes a detailed written policy, proper training, management oversight, and purchasing and inventory control. Proper lighting maintenance is necessary both to maximize energy savings and to maintain lighting efficiency. Poor lighting maintenance results in visual degradation that can lower worker productivity and contribute to higher utility bills.

The following are the principles of lighting maintenance:

• The light output of lighting systems decreases over time.
• Many lighting systems are over-designed to compensate for light loss over time.
• Improving maintenance practices can reduce light loss and allow reductions in energy use and improve light levels.
• Group maintenance practices save money.
• Proper maintenance is the most neglected, yet most cost effective way of reducing the overall cost of lighting.
• When maintenance is not performed, performance suffers gradually. The final result is a degraded lighting system performing at as low as 50% of its capability.

Basic Maintenance Procedures

Light levels decrease over time because of aging lamps and dirt on fixtures, lamps, and room surfaces. Together, these factors can reduce total illumination by 50% or more, while lights continue drawing full power. The Energy Efficiency and Renewable Energy Network (EREN) offers the following basic maintenance suggestions to help prevent light loss:

• Clean fixtures, lamps, and lenses every 6 to 24 months by wiping off the dust. However, never clean an incandescent bulb while it is turned on. If a damp object is used to remove the bulb's dust, the liquid's cooling effect may shatter the hot bulb.
• Replace lenses if they appear yellow.
• Clean or repaint small rooms every year and larger rooms every two to three years. Dirt collects on surfaces, which reduces the amount of light they reflect. Repainting is not advantageous for existing dark colored rooms that the owner wants to remain a dark color.
• Consider group relamping. Common lamps, especially incandescent and fluorescent lamps, lose 20% to 30% of their light output over their service life. Many lighting experts recommend replacing all the lamps in a lighting system at once. This saves labor, keeps illumination high, and avoids stressing any ballasts with dying lamps.

Replacing Lamps and Fixtures

Source: www.sxc.hu

Relamping means substituting one lamp for another to save energy. You can decide to make illumination higher or lower when relamping. But be sure that the new lamp's lumen output fits the tasks performed in the space and conforms to the fixture's specifications.

When relamping an entire store or office, first test the new lamps in a small area to ensure adequate illumination, occupant satisfaction, and compatibility of the new lamp and the old fixture.

Matching replacement lamps to existing fixtures and ballasts can be tricky, especially with older fixtures. Buying new fixtures made for new lamps produces superior energy savings, reliability, and longevity compared with relamping.

Relamping Incandescent Fixtures

Much has been learned about fixture design since the energy crisis of the 1970s. Many indoor fixtures trap a significant portion of light inside the fixture, while many outdoor fixtures tend to disperse much of their light beyond the intended area, which causes light pollution.

New incandescent fixtures are designed to push all of their light out into the room. Others use smaller tungsten halogen lamps. Advances in indoor fixture design include brighter reflectors and better reflecting geometry.

Many incandescent lamps are mismatched to their tasks. Some have excessive wattages, which create unnecessarily high illumination. This can be corrected by using lamps with smaller wattage.

Some existing incandescent lamps may not be the best type of lamp for their application. "A"-type light bulbs can often be replaced with improved lamp designs, such as reflectors or tungsten halogen lamps. And, for energy savings of 60% to 75%, many incandescent lamps can be replaced by CFLs (compact fluorescent lamps).

When used in recessed fixtures, standard A-type lamps and reflector lamps waste energy—their light gets trapped. To save energy, you could replace a 150-watt standard reflector with a 75-watt ellipsoidal reflector (ER). Remember, though, that ER lamps are less efficient at delivering light from shallow fixtures, so use standard reflectors or parabolic reflectors for these purposes.

You can also replace standard A-type lamps with CFLs in spaces where lights are needed for long periods of time. A standard 18-watt CFL replaces a 75-watt A-type lamp. CFLs are also packaged in the same glass reflector lamps as incandescent lamps. Use CFLs packaged as ellipsoidal reflectors (type-ER) in recessed fixtures. Use standard reflector (R) or parabolic reflector (PAR) CFLs for flood and spotlighting. New CFL fixtures have built-in electronic ballasts and polished metal reflectors.

Relamping Fluorescent Fixtures

Although fluorescent lamps are generally energy efficient, there are a range of fluorescent lamps from which to choose, including T8s and T5s to replace the older T12s. The T8s and T5s use better electrodes and coatings than do older fluorescent lamps. The T8s can produce about the same lumen output with substantially lower wattage. The T5s are even more efficient, but may produce glare if not fixtured properly.

Common 40-watt and 75-watt lamps can be replaced with 34-watt and 60-watt energy saving lamps, respectively. Energy saving lamps for less common fluorescent fixtures are also available.

If you need to replace the ballasts in your fluorescent fixtures, consider using one of the improved varieties. These fluorescent ballasts, called improved electromagnetic ballasts and electronic ballasts, raise the efficiency of the fixture by 12% to 30%.

The new electromagnetic ballasts reduce ballast losses, fixture temperature, and system wattage. Because they operate at cooler temperatures, they last longer than standard electromagnetic ballasts.

Electronic ballasts operate at a very high frequency that eliminates flicker and noise. They are even more efficient than improved electromagnetic ballasts. Some electronic ballasts even allow you to operate the fluorescent lamp on a dimmer switch, which usually is not recommended with most fluorescents.

Spot Versus Group Relamping

In spot relamping, lights are replaced only as they burn out, whereas in group relamping, all lights are replaced simultaneously according to a maintenance schedule. Studies have shown that group relamping has higher lamp costs, while spot relamping requires higher labor costs. Group relamping does have a few advantages over spot relamping that may make it beneficial in certain circumstances.

• Group relamping is easier to schedule and oversee than spot relamping. Also, this is an easy task to hire to outside contractors, potentially reducing the size and cost of in-house maintenance staff.
• Group relamping provides increased control over relamping, reducing improper mixing of different types of lamps and ensuring that only the most efficient fixtures are used. Group relamping also ensures efficiency by replacing all lamps before they begin to degenerate.
• Combine relamping with other maintenance activities such as ballast inspection and lens cleaning.

Training

Proper training is necessary for maintenance personnel to effectively operate an efficient lighting system. Training should include a thorough understanding of lighting maintenance procedures, such as cleaning, lamp and fixture replacement, fixture inspection, and so on. Maintenance personnel should also be aware of the different types of lighting and the relative costs of each type in a lighting system. Most importantly, training should include a detailed knowledge of the written lighting maintenance policy and each employee’s role within. Periodic retraining on an annual basis is essential to maintain knowledge of any new technologies or policy changes, and to account for personnel changes.

Lighting Maintenance Policy

A written lighting maintenance policy can contribute to energy savings and increased lighting efficiency and should be a part of your building’s facility management guide or manual. A lighting maintenance policy should include the following basic elements:

• Blueprints of the facility
• Fixture and lighting controls schedule
• Specifications of all lighting equipment
• Equipment and service provider sources and contacts (include utility contacts)
• Fixture cleaning and relamping schedule with service tracking log
• Procedures for relamping, reballasting, and cleaning fixtures
• Procedures for the adjustment of controls and occupancy sensors
• An overview of proper lamp and ballast disposal