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by Randall Whitehead

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When an ill-lit house leaves owners uncomfortable, they are often unsure of exactly what's wrong. Sometimes aspects of the design or construction get the blame when the culprit is improper lighting.

Lighting designers often talk of four different types of light: ambient, task, accent, and decorative. A single light source is rarely able to provide more than one type of light, so almost all rooms require multiple light fixtures.

Ambient Light

Ambient light (or fill light) is the soft, general illumination that fills a room and softens the shadows on people's faces. It comes from indirect sources that bounce illumination off the ceiling and walls, and it is essential in almost every room. If it's the only type of light in a room, however, the result is a "cloudy day" effect, where everything in the room looks flat, without depth or dimension. The fixtures (or luminaires, as they are called in the lighting industry) used to provide ambient light should not draw attention to themselves. You can't provide ambient light by filling a room with table lamps with linen shades: Since bright lights draw one's gaze, the space becomes a lampshade showroom. Ambient light is best provided by opaque wall sconces, cove lighting, torchiere floor lamps, or indirect pendants. An indirect pendant is a dish-shaped hanging fixture that throws most of its light up toward the ceiling (see Figure 1).

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Figure 1. Indirect pendant fixtures, like this white clay lamp from Fabby Lighting, direct most of their light up toward the ceiling. This lamp is designed for two 75-watt bulbs and provides enough ambient light for a medium-sized room.

Ambient light sources work only if the ceiling is light in color. A dark wooden ceiling absorbs light instead of reflecting it; one solution is to lighten the color of the ceiling; another is to use an RLM pendant fixture with a silver-bowl reflector bulb. (RLM is a generic term for a cone-shaped metal warehouse fixture; the interior of the cone is always white.) The silver-bowl reflector bulb bounces the light back up toward the inside of the fixture. Essentially, the RLM fixture provides its own ceiling. And the light is bounced off the inside of the shade. Some manufacturers produce modern versions of the RLM, like the Spectro by Boyd Lighting or the T-8100 by Estiluz (Figure 2).

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When a pendant fixture like this RLM luminaire from Abolite (left) is fitted with a silver-bowl reflector bulb, the light bounces upward. Similarly, the Spectro pendant fixture from Boyd Lighting (right) provides indirect light by bouncing light off an etched glass disk. Wall sconces. Wall sconces should be opaque, not transparent, so that the light will be softer and will not draw the eye to the fixtures (Figure 3). Sconces almost always come in pairs, and they can be used to flank a door, fireplace, or console table. Two sconces are often adequate to provide ambient light in the average room, while four are usually ideal. In most cases, more than four is overkill.

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Figure 3. Wall sconces used for ambient lighting should be opaque, so that the fixtures themselves aren't bright enough to be distracting. This clay sconce from Fabby Lighting can be ordered in two designs, for either a single 150-watt incandescent bulb or two 13-watt compact fluorescent bulbs. Cove lighting is installed near the ceiling, behind a cornice or ledge (Figure 4). Suitable fixtures include strip lights with miniature incandescent or xenon lamps, compact fluorescents, or standard-length fluorescent tubes (see "Incandescent or Fluorescent?" below).

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Figure 4. The ambient light in this room is provided by cove lighting mounted above the ledge and cantilever.

For cove lighting, I usually recommend either xenon or fluorescent lamps, and I plan on between 20 to 30 watts per foot for either type. One of our favorite fluorescent fixtures for cove lighting is the Belfer Ramp fixture (2855 NX2), which uses overlapping size 2611 compact fluorescent lamps.

If a room has a 9-foot ceiling, cove lighting can be installed between 12 and 24 inches down from the ceiling. In a room with an 8-foot ceiling, cove lighting is typically installed 12 inches down. This can leave the center of some rooms rather dark; the solution is to include an indirect pendant fixture in the center of the ceiling.

Incandescent or Fluorescent?

One of the first decisions when shopping for fixtures is what type of bulb to choose. In the lighting industry, bulbs are called lamps. Incandescent bulbs, the standard lamps for over a century, now come in several new varieties, including halogen and xenon.

Standard incandescent. Incandescent bulbs have several advantages:

• They are inexpensive and widely available.

• They are easily dimmed.

• They are available in a wide range of wattages.

They also have several disadvantages:

• The lamp life is relatively short (about 750 hours).

• The light yellows as the lamp is dimmed.

• They are the least energy efficient of available lamps.

Halogen. The halogen (or quartz) lamp is an improved version of the incandescent lamp. Halogen lamps contain halogen gas, which allows the bulb to burn brighter and last longer.

Advantages of halogen lamps:

• They are usually smaller than standard incandescents.

• They last longer than standard incandescents (2,500 to 3,000 hours).

• They are more energy efficient than standard incandescents.

• They lend themselves well to being focused in a narrow beam.

Disadvantages of halogen lamps:

• The light yellows as the lamp is dimmed.

• Dimming may shorten the lamp life.

• The glass envelope of the lamp should not be touched without gloves on.

• Halogens can get very hot, and some types of halogen fixtures have been associated with fires.

Many halogen fixtures operate at 12 volts DC and require a transformer (see “Low-Voltage Lighting,” 5/96).

Xenon. Xenon lamps are similar to halogen lamps, with several advantages:

• They don’t get as hot as halogen lamps.

• The lamp life is much longer than that of halogen lamps (about 20,000 hours).

• There is no need to avoid handling xenon lamps with your fingers.

Fluorescent. In recent years, residential use of fluorescent lamps has greatly increased, due to improvements in fluorescent ballast technology and greater variety in the available color rendition of fluorescent lamps. Moreover, some states, including California, have mandated the inclusion of energy-efficient fluorescent fixtures in kitchens and bathrooms.

Fluorescent lamps require a ballast; most compact fluorescents include the ballast with the lamp. Solid-state or electronic ballasts are less likely to hum than heavy magnetic ballasts. The best types of electronic ballasts permit fluorescent lamps to be dimmed.

Advantages of fluorescent lamps:

• They last a long time (between 10,000 and 22,000 hours).

• They are very energy efficient (providing three to five times the light output per watt of a standard incandescent).

• They produce less heat than a standard incandescent or a halogen, so they can be installed closer to combustible materials in a closet.

• They do not change much in color when dimmed.

Disadvantages of fluorescent lamps:

• Some ballasts, especially cheap magnetic ballasts, have an irritating hum.

• As they age, they produce less light (halfway through their expected life, they may produce 20% less light than when new).

• They are usually large and are hard to focus for accent lighting.

• They can be hard to start in cold temperatures, although cold-weather ballasts are available to solve that problem.