Title: Reading and Audio-Visual Assignments
Course: WGF 107 DEVELOPMENT > Section: Content

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Sub-Title | Building Lighting Maintenance Requirements
Content
O&M managers should consider developing and implementing a maintenance action plan that include both regular cleaning and delamping to achieve the full range of benefits generated by well-maintained lighting. Develop a lighting system maintenance policy and review it with your maintenance team to ensure they use the correct lamps and ballasts and that they clean and maintain lighting system and sensor components properly.

Benefits of Regular Cleaning

The routine cleaning of lamps and fixtures is one of the most important (and sometimes, most neglected) tasks in lighting O&M. All light sources used for interior lighting lose their ability to produce light as they age. Light levels from fluorescent systems can decline gradually over a period of months, due to dust accumulation and system decline. This condition is more noticeable with fluorescent systems due to their longevity. The term “lamp lumen depreciation” (LLD) describes this phenomenon. The values of LLD, also called lumen maintenance, vary between lamp types and manufacturers.

Generally, the LLD characteristics of T8 fluorescent lamps are better than those of T12 lamps, as the newer lamp types with rare-earth phosphor tend to lose less light output over time. The T8 lumen depreciation curve tends to level off as it reaches its low point at about 90%, instead of continuing to depreciate as the T12 does. In addition, new T8 HO (high output) lamps have especially good lumen maintenance. Figure 3 compares light output over time for different linear fluorescent lamp types

Because of the light from both LLD and poor maintenance practices, lighting designers typically plan for more fixtures and bulbs than needed to ensure sufficient light levels. Therefore, a good maintenance plan that includes routine cleaning alone can justify the de-lamping of some spaces. Typically, the money saved in energy and lamp costs from delamping can more than pay for the regular fixture cleaning and delamping practices, depending on the size of the facility. Lamp cleaning practices are simpler today, as buildings tend to be less dusty, especially in facilities in which smoking is limited to designated areas.

A number of sources of dirt and dust remain even in non-smoking buildings, especially in kitchens and laundry areas. These areas are often overlooked, but they greatly contribute to the amount of dust and dirt generation. Clothes dryers release fine dust that can coat fixture surfaces. The most effective solution is to move these types of equipment to an area with a separate exhaust

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Replacing incandescent lamps with CFLs can significantly extend maintenance periods, but can allow more dust and dirt to accumulate on fixtures between replacements. Therefore, the routine cleaning of lamps and fixtures that have been retrofitted with CFLs should be part of the overall maintenance routine. At a minimum, fixtures, covers/reflectors, and lenses should be cleaned when lamps are replaced. Depending on where the CFLs are used, more frequent cleaning may be required for high use/high dust areas such as laundry areas, bathrooms, and kitchens.

Cleaning Methods

It is recommended that the lamp-replacement crew clean the interior reflecting surfaces of fixtures when lamps are changed.

In some environments (such as offices), fixtures may need to be cleaned before the lamps are replaced, but in most interiors, cleaning at lamp change intervals (for group delamping) may prove to be adequate.

Generally, cleaning fixtures and lamps does not require harsh chemicals or volatile cleaning solutions. Fixtures usually require a simple dusting of the interiors, as well as the dusting of lamps, depending on your cleaning and re-lamping schedule. Below are recommended environmentally safe fixtures and lamp cleaning practices:

·        Clean fixtures and lenses at every relamping, and replace lenses whenever ballasts are replaced.

·        Unusually dirty fixtures or multi-celled, metal parabolic louvers may need to be professionally cleaned with an ultrasonic machine.

·        Lamp and fixture cleaning can typically be done with soft, moist cotton cloth, which needs to be continually turned to present a clean surface as the cloth becomes dirty. Care should be used to keep the cloth moist, thereby avoiding the building up of static electricity, which will re-attract dust. Other re-useable cleaning devices (such as a soft-bristled brushes with anti-static material or low-powered hand vacuum) can and should be used instead of disposable materials.

·        Most fixtures’ acrylic lenses can come clean with a mild solution of dishwashing detergent, while glass covers can be clean with diluted vinegar or other mild glass cleaners. Both sides of the lens should be rinsed and allowed to air-dry. (A dirty lens can reduce a fixture’s light output up to 50%).

·        Static electricity can be a problem in attracting airborne dirt for some fixtures. The use of an anti-static material, such as an environmentally safe laundry fabric-softener in the rinse water, is a possible solution where static electricity is a problem.

There can be some resistance to cleaning practices when electricians or maintenance crews are asked to clean lamps and fixtures instead of custodial workers. Usually, electricians can be put towards more productive tasks than changing lamps or cleaning fixtures. In addition, custodians who are tasked with

delamping may be more likely to clean fixtures properly.
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Content
Lamp/Fixture Troubleshooting

If your O&M practice involves individual replacement of fluorescent lamps (especially linear tubes) as they burn out, consider switching to replacement of all lamps or all lamps of the same type at once on a set schedule, based on the lamp types in use and their rated hours. However, if group replacement is not an option in your maintenance schedule, consider adopting or incorporating other maintenance tasks into the replacement routine, such as fixture cleaning and ballast inspection, to maintain light output and keep fixtures at peak performance:

Action Items

1.     Set a regular inspection schedule and a replacement schedule for lamp replacement in common areas (at a minimum).

2.     Select replacement linear lamps with a minimum of 20,000 hours rated life.

3.     Use fluorescent lamps with low mercury content (3.8 mg per 4-ft lamp or less).

4.     Use CFLs (compact fluorescent lamps) instead of incandescent bulbs.

5.     Replace existing lamps with more efficient equivalents.

6.     Use specifications for bulk purchasing to obtain the appropriate lamps.

7.     Inspect building for lamp failures on a periodic basis (monthly or longer, depending on the types of lamps in use).

8.     Do not wait for complaints from users.

9.     Set up a maintenance request system for occupants to report lamp failure.

10.  Inspect ballasts and perform other maintenance (such as cleaning) on a regular basis.
Links/Uploads | Lighting – Chapter 4 (Green Building O&M Manual – Green Seal http://www.greenseal.org/Portals/0/Documents/IG/PHA%20Manuals/Chapter4_Green_Building_OM_Manual_PHA.pdf
Attributions | Image courtesy of Sustainable Facilities Tool – U.S. General Services Administration Content courtesy of Green Seal