I’m pleased to announce that I have finally completed the long awaited (by my publisher) update to The Lighting Management Handbook, which came out in 1994, with this 300-page book about redesigning existing lighting systems: Lighting Redesign for Existing Buildings.

Because light is used to see but cannot be seen, it is often overlooked by its users. The presence of light is rarely noted, in fact, unless there is a perceived lack of it (dim atmosphere or shadows) or a perceived excess (glare). Like air, however, light is invisible and yet everywhere in the visual environment, as we cannot see without it. And seeing, in turn, is fundamental to economic and leisure activity for the large majority of the population who are sighted. Like electricity and clean water, light is an engine of progress.

Ubiquitous in the built environment, light is generally considered a commodity, and the main economic consideration is how to obtain it more cheaply. For this reason, educated owners of new and existing buildings are finding it highly profitable to invest in energy-efficient equipment to reduce lighting energy costs by as much as 50 percent or more. These projects often take the form of simple lamp and ballast replacements.

These investments can be a great uses of capital. They can also be a waste of money, even if the project achieves an excellent financial return based on lower operating costs. The reason is simple: Light is for people, not buildings. Decisions about light may be all about dollars and cents, but dollars and cents are not all about energy.

In short, it is not enough for light to be energy-efficient. It must also be effective. What does it mean for a lighting system to be energy-effective?

First, we must understand that the application of light is lighting—not only the equipment that acts as the delivery system for light, but also where the equipment places light and with what direction, intensity and color. As people respond to varying levels of brightness and color in the field of view, light can be applied to the same space to impact a building and its occupants in different ways. While light makes sight, lighting is about perception—whether a space appears tense or uninteresting, public or private, spacious or intimate, productive or relaxing, and so on. Some 80 percent of sighted people’s impressions of the world, in fact, are generated by what they perceive with their eyes. This is where lighting delivers tangible economic benefits beyond simple vision. Properly applied, lighting can produce higher sales of key merchandise, optimize the productivity of office workers, offer a memorable experience for visitors, beautify space and architecture, improve learning rates, influence human interaction and mood and atmosphere, and promote safety and security.

It should be noted that bad lighting can realize opposite effects.

Given the benefits of good lighting design, and the high economic stakes involved, we may be thinking about light all wrong. Yes, light is a commodity. But lighting is a business asset—a critical asset of both the built environment and the organization that occupies it.

In existing buildings, this asset is often neglected. According to the Department of Energy, while lighting upgrades are a popular renovation investment, lighting upgrades have been performed in only 29 percent of commercial building floorspace built before 1980. This suggests that about 25 billion sq.ft. of floorspace is still lighted to pre-1980 standard using T12 lamps, magnetic ballasts and overlighted spaces.

Upgrading these lighting systems to today’s lighting efficiency standards could generate lighting energy cost savings of up to 50 percent or more. As the fluorescent magnetic ballast becomes virtually eliminated in 2010 and the fluorescent T12 lamp with it in 2012, building owners should begin exploring opportunities to convert their lighting systems to more-efficient technologies in a way that achieves maximum benefit. But focusing solely on how much energy a lighting system uses is like buying a forklift based solely on its fuel efficiency instead of how much it can lift, how it handles, its speed, safety features and so on. After all, the purpose of lighting is not to draw wattage, but instead, depending on its application, to enhance task performance, provide visual comfort, reveal form and architecture, attract interest and so on. In short, lighting should be effective as well as efficient.

Here, too, research suggests that the lighting asset is often neglected in buildings in terms of lighting quality, perpetuating lighting systems that may have been poorly designed or designed to outdated standards, and poorly maintained since then. According to a 1999 office lighting survey conducted by office systems manufacturer Steelcase, 37 percent of workers said the lighting in their workspace was either too dim (22 percent) or too bright (15 percent), while three out of four said they wanted more control over light levels. Further, three out of four office workers said better lighting would improve their efficiency and productivity, while two out of three said they would be more creative.

This means simple replacement of lamps, ballasts and controls is not enough. A component-based retrofit approach may save energy, but perpetuate a poor design that fails to achieve the business goals of the organization that invested in owning the asset and wants to realize its value. Instead, the lighting system may need not retrofit, but relighting—a redesign that addresses effectiveness as well as energy performance, including issues such as visual comfort, uniformity, color rendering and light on walls and ceilings. Because it is not enough for a lighting design to be efficient; it also has to shine.

Some of these issues run deep, and can be challenging to address properly at very low levels of energy consumption. As complexity increases due to advancing lighting technologies and an imperative to optimize lighting quality as well as energy efficiency, so has demand for greater expertise from designers of lighting systems.

Lighting Redesign for Existing Buildings was written to educate owners, energy managers, electrical engineers, architects, lighting designers, consultants, electrical contractors, electrical distributors and other interested professionals about the relighting of existing buildings. The information may apply to lighting design in new construction as well. Its thinking transcends my first book about lighting upgrades, The Lighting Management Handbook, published by The Fairmont Press more than 15 years ago, challenging owners and designers to optimize lighting quality hand in hand with efficiency in existing buildings—and get the full value of an asset that is effective as well as efficient.

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Craig DiLouie

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