Interior Lighting Systems
Light Levels
We measure lighting intensity by the amount of light generated by a single candle. The total amount of light emitted in all directions from a flame is 1 candela. Luminous flux is the amount of light that strikes a surface at a distance from the candle, measured in lumens (lum). In the International System (SI) of units, 1 lumen is the amount of light energy that 1 candela yields on a spherical surface of 1 square meter at a distance of 1 meter from the candle. The American System (AS) uses the foot-candle (fc), where 1 fc is the amount of light that falls on 1 square foot of spherical surface at a distance of 1-foot from the candle. The relationship between lumens and foot-candles is:
1 lum = 12.57 fc
You probably have an idea of how much light a 75-watt (W) incandescent bulb delivers. However, as a designer, you should get used to comparing light output in lumens, not watts, because wattage measures only the power consumed, not the light produced. And lamps differ in their light output per watt. A 15W compact fluorescent (CFL) lamp, for example, delivers as many lumens as a 75W incandescent bulb, as do some other types of lamps that have emerged in recent years to replace incandescent lighting.
Luminous flux is the amount of light that strikes a surface, measured in lumens. A candle set 1-foot away from a curved surface of 1 square foot produces 1 lumen in the American system. In the International System, 1 lumen is the amount of light that falls on a curved surface of 1 square meter at a distance of 1 meter.
Color of Light
We didn’t think much about light color in the old days, when the choices were limited to incandescent or fluorescent lamps. We knew that the warm light of incandescent lamps complemented people’s skin tones and enhanced foods, such as meat and most vegetables. The cool light of fluorescent lamps made people look ashen but green salads look more appetizing. But what exactly do we mean by “warm” or “cool” light?
The lighting industry uses two color indices for lighting color: color temperature and color rendition. Color temperature is an index of how the light source itself looks to us, measured in kelvins (K). Warm-light sources have color temperatures less than 3000K. Light sources between 3000K and 4000K are considered neutral in color. Anything above 4000K is cool.
Color temperature of light sources.
Color rendition is an index of how the light makes objects appear. How accurately a lighting source defines objects is measured by the color rendering index (CRI). The best score is 100, the CRI of sunlight.
Two indices are needed because sources with the same CRI can produce different moods at different color temperatures. When specifying fluorescent lamps for home applications, you’ll get the best all-around light color with tubes coated with rare-earth phosphors. Artificial light sources vary widely in their color rendering indices. Incandescent lamps are rated at a CRI of 100—nearly equal to sunlight. Lamps with very low CRI numbers are unacceptable in home lighting. Those ghastly orange street lamps that use high-pressure sodium have a CRI of 22. The table below compares various lighting sources by their physical characteristics. Here are some rules of thumb for selecting lamps for the right color:
- Task, accent, and art lighting. Use halogen or xenon lamps. Small-voltage lamps, such as PAR halogen or MR 16, work better for art, because they throw their heat back away from the object.
- General lighting. PAR halogen and compact fluorescents work well, but make sure the compact fluorescents have a color tem-perature of about 3500K (they range from 2700 to 6500K). If you use fluorescent tubes, choose lamps with a CRI over 80 and a color temperature of between 3000 and 3500K.
Comparing Lighting Sources
Light Quality
When we say, “Let’s use recessed lighting,” that is shorthand for light directed down from the ceiling. But it does not indicate whether the light will flow in a concentrated beam or a more diffuse one or even asymmetrically. And, depending on the listener’s experience, the phrase “recessed lighting” may conjure small, sparkling luminaires, large cumbersome ones, or something altogether different.
Regardless, at this stage of the design, the phrase “recessed lighting” is too vague to describe the effect of the light and perhaps too specific (in the mind of the listener) to describe the luminaire itself.
The next section provides vocabulary to communicate how light can be applied in a space—that is, how the various layers of light can be achieved.
Direction
We commonly speak of the direction of light in spatial terms: down light and up light. While these terms are unambiguous, they do not express the effect of the light.
Effect is better conveyed by how the light reaches a target.
- Direct light reaches a target directly, without reflecting off another surface. Since direct light is not diffused by reflection, it tends to be more concentrated and so produces more highlight and shadow. Direct light does not imply down light, although that is the most common example. A table lamp or an under-cabinet luminaire produces direct lighting effects.
- Indirect light reflects off a surface (typically the ceiling or a wall). Reflecting off a matte surface diffuses the light, which spreads out and diminishes the form and texture of the objects it ultimately illuminates (see Figure 6.20).
- Backlight reaches an object from behind and does not reflect in the direction of the viewer. As a result, the object becomes silhouetted against the source of the light.
The under-cabinet lighting below the microwave and the table lamp in the adjoining room are examples of direct light. Design by Mark T. White, CKD, CBD, Kitchen Encounters, Annapolis, MD Photo by Phoenix Photography
The lighting fixtures in this bathroom are examples of indirect light. Design by Lori W. Carroll, ASID, IIDA, codesigners Debra Gelety, Allied ASID, EDAC, and Mary M. Roles, Lori W. Carroll & Associates, Tucson, AZ Photo by William Lesch Photography
Backlighting was used for this striking wall design behind the cooktop. Design by Kaye Hathaway, CKD, NCIDQ, ASID, codesigner Catherine Heir, Dea Design Group, LTD, Island Lake, IL Photo by Jozef Jurcisin
Note that light reflecting off a specular surface (such as a mirror) does not diffuse and acts more like the direct light from the source.
Concentration
As noted, concentrated light produces sharper highlights and shadows, revealing form and texture. Diffuse light softens shadows and diminishes the perception of form and texture.
Orientation
Now it is appropriate to speak of downlight and consider whether the light is oriented to a wall or vertical surface. The table below combines the effects of direction, concentration, and orientation, showing typical effects produced.
| Direction | Concentration | Orientation | Effect |
|---|---|---|---|
| Direct | Concentrated | Down | Focal pool of light |
| Concentrated | Wall | Focal accent on painting | |
| Concentrated | Down the wall | Focal graze | |
| Diffused | Down | Ambient light | |
| Diffused | Wall | Ambient wall wash | |
| Indirect | Diffused | Up | Ambient light |
| Diffused | Up | Backlight and silhouette |
What, Where, How
Another analytical approach to lighting is to ask three fundamental questions:
- What should be lighted?
- How should it appear when lighted?
- Where can it be lighted from?
Clearly, these questions do not specifically address layers of light. Instead, they organize the design process.
What Should Be Illuminated?
Applying the functional layers of light, our list might include:
- Counter tasks
- Cooktop tasks
- Cabinet tasks
- The entire room
- Collectibles in the breakfront
- Paintings on the wall
See the table below for lighting recommendations.
| What | Brightness | Color Rendering | Distribution |
|---|---|---|---|
| Counter tasks | High | Excellent | Diffused to avoid shadows |
| Cooktop tasks | High | Excellent | Concentrated on task |
| Cabinet tasks | Medium | Good | Diffused over cabinet fronts |
| Overall space | Medium to low | Excellent | Diffused to avoid shadows |
| Collectibles | Medium | Good | Focused on objects |
| Paintings on wall | Medium | Excellent | Diffused to cover paintings |
How Should It Be Illuminated?
What characteristics would we use to describe the desired lighting effect? Brightness, color, and the distribution of light (concentrated or diffused) would certainly rank as three of the most important considerations.
The table below is a simplified approach to answering the question, “How should it be illuminated?” At this point, specific illuminance levels are not part of the design process; however, relative brightness is important.
| What | Issues | Location |
|---|---|---|
| Counter tasks | Shadows created by usersVeiling reflections | Under cabinetAt front edge of cabinet |
| Cooktop tasks | Shadows created by hood | Integrated in hood |
| Cabinet tasks | Reaching sop shelvesAvoiding sharp shadows on door | Ceiling, moderately close to cabinets |
| Overall space | Non-distracting diffuse quality | Ceiling |
| Collectibles | Clear rendition of form | Inside breakfront, at front edge |
| Paintings on wall | Several small paintings | Ceiling, parallel to wall |
Arguably, all of the lighting should deliver excellent color. And a single level of color quality is often used. Nevertheless, color quality is more significant when looking at people and art than when doing something like reading, where color is not an important factor.
Where Should It Be Illuminated From?
Sometimes architecture determines the location of the lighting equipment. Sometimes location depends on the quality of light desired. Although the ceiling provides a convenient location for lighting equipment, both people and cabinetry can get in the way. For example, high or sloped ceilings often make recessing lighting equipment impractical.
Illumination Types
Good interior lighting provides enough of the right kind of light for whatever activities the occupants are engaged in at the moment. That can mean anything from being able to see the chopping block when cutting up vegetables in the kitchen to creating a relaxing mood with the soft glow of a special lamp above a dining table. Sorted by function, there are six types of lighting: ambient, wall-mounted task, indirect, decorative, and accent lighting.
See Guideline 8.3:
| Table 8.3 | Illumination Types |
| General (Ambient) | Provides illumination for safe passage and circulation within the space. |
| Overhead Task | Planned directly above the surface to be illuminated, between the wall or cabinet above the work surface to the front edge of the work surface. |
| Wall-mounted Task | Planned from the user’s eye-level height of the user, seated or standing. |
| Indirect | Includes under-cabinet lighting, toe-kick lighting, up-lighting or cove lighting in the ceiling. Under-cabinet lighting should be planned near the front edge of the cabinet or shelf for maximum illumination effectiveness. |
| Decorative | Planned in consideration of the user’s height at a standing or seated position to avoid conflict with shadows. Decorative lighting uses a lower illumination output of lamp(s), additional task or downlighting may be needed to adequately illuminate an activity center. Also qualifies as General Lighting. |
| Accent | Accomplished with a variety of lighting fixture types to highlight a focal point. Accent lighting can create the effect of wall-washing, grazing or spot-light illumination. |
Light Sources
Artificial lighting varies by the way it is produced, its color, energy consumption, and lamp shape and sizes. And by lamp, we mean the basic item we fit into a fixture, which is the assembly that includes the mounting base, or socket, and features that reflect or disperse the light from the lamp. To select the right type of lighting source for a particular application, you need to understand both. Manufacturers’ catalogs, whether in bound copies on your bookshelves or accessed over the Internet, are the best sources of information for fixtures.
Lamps are described by their shape and the way they produce light. In the past few years, the choices have expanded to include types that are more energy efficient and longer lasting than traditional incandescent lamps.
Incandescent
Ever since Thomas Edison invented the first commercially practical incandescent light bulb in the late 1800s, incandescent lamps have been the mainstay of home lighting. They haven’t changed much since the early models, either, and still offer a warm, friendly color, a low initial price, and convenience. Their light comes from a tungsten filament that has high resistance to electrical current. Passing an electrical current through the filament converts some of the energy into light, the rest into heat. Because of the high heat, incandescent lamps are the least efficient electric lighting sources available. Their advantage of a low initial cost is eaten away in time, because bulbs burn out after about 750 hours of use. Although incandescent lamps still are available, they are being phased out and likely will disappear in the future — in fact, many jurisdictions across North America have already banned the use of incandescent lighting. Incandescent lamps come in several shapes, each suited to a special lighting application, as described next.
Although they are being replaced by more efficient lighting, incandescent lamps are still available in several versions. A, G, PAR, and R bulbs screw into standard sockets; B and CA tipped bulbs screw into smaller sockets. Mini bulbs twist into special sockets and require a transformer to step the voltage down to 12 volts.
- A lamps are the basic bulbs with standard screw-in bases that come in wattages from 7 to 150. They throw light in all directions from the bulb pretty equally and suit general illumination or task lighting when fitted into a fixture that has a reflector.
- G lamps are similar to A lamps but with bigger and rounder globes, hence the designation “G.” The shape, however, is an aesthetic ra-ther than functional feature. These lamps are intended for fixtures that do not hide the bulb, such as strip fixtures around mirrors in baths.
- R lamps and PAR lamps have built-in reflectors to limit the light throw. An R lamp throws out a cone-shape light pattern, whereas a PAR lamp directs its light in a cylindrical pattern, thanks to its parabolic-shape reflector. Both types are used in spotlights and can-type fixtures. Wattages range between 50 and 150.
- B lamps and CA-tipped lamps are small bulbs for decorative uses, such as in chandeliers. B lamps are oval, and CA tipped lamps are flame shape. Both have screw-in bases but are of smaller diameters than A lamps. Wattages range from 25 to 40.
- Miniature (mini) bulbs, also used for decorative applications, come with wedge bases and bayonet bases.
Fluorescent
Fluorescent lamps yield five times as much light for the same amount of power as incandescent lamps and last much longer. These advantages have made fluorescent lighting the first choice for commercial buildings for years. The first generations of fluorescent lamps had a bluish light color that made people look like ghosts and made meat in counters look gray. Due to this problem, even commercial buildings limited the use of fluorescent lighting to general lighting. The color ruled out fluorescent lighting for all but garages and basements of most homes. All that changed in the 1980s when newer coatings for the insides of fluorescent tubes resulted in light that was much warmer colored.
Fluorescent lamps come in a wide variety of shapes and color renditions. Compact fluorescent bulbs screw into standard 120V sockets and yield outputs from 300 lumens (7W) to 1,600 lumens (23W).
Another change that made fluorescent lighting acceptable in homes came around the same time, when manufacturers found ways to squeeze a long tube into a bulb that screwed into a standard household lighting fixture socket. The result was compact fluorescents that were not only interchangeable with incandescent bulbs but delivered a more flattering light color to skin and most foods. Today’s compact fluorescent lamps cost more initially than incandescent lamps but save in the long run due to their lower operating costs and longer life-times. For these reasons, they are rapidly replacing incandescent lamps.
Fluorescent lamps do not contain a resistance filament, as incandescent lamps do. Instead, a heated cathode at one end of the tube produces free electrons, which are accelerated by a voltage placed across the electrodes at either end of the tube. As they accelerate, they ionize a gas vapor (mercury) in the tube, causing an arc to flash the length of the tube. The arc excites the vapor in the tube to produce light. All fluores-cent lamps need ballasts to heat the cathode and run the tubes at the correct voltages. Straight-tube fluorescents have as separate ballast housed somewhere within the fixture. Compact fluorescents contain the ballast within the base. Standard magnetic-type ballasts produce an annoying flicker as well as perceptible hum, and lamps coupled to them are not dimmable. The newer solid-state electronic ballasts are quieter, with less flicker, and do allow dimming. Another downside of all fluorescents is the small amount of mercury they contain, which poses a risk if the lamps are broken in the home. Municipalities often have regulations for the disposal of burned-out or broken bulbs.
Fluorescent tubes make good candidates for side lighting of bathroom mirrors and under-cabinet lighting for kitchen countertops. But for applications in kitchens and baths, stay away from lamps in the cool-color range. Warmer-colored daylight, deluxe cool white, warm white, or natural lamps complement skin tones and most foods.
Halogen
Tungsten halogen (or simply “halogen”) lamps encase the filament of an incandescent lamp inside a capsule containing halogen gas produced by iodine vapor. The gas slows filament wear through a complicated regenerative cycle and improves the lamp’s efficiency. Halogen lamps cut energy use by 30 to 50 percent compared to long-life incandescents. Lamp life ranges between 2000 and 3500 hours. The light color is whiter than incandescent lamps, but not bluish enough to make food look bad. Halogen lamps are available in low-voltage (12V) and standard (120V) voltages, in reflector shapes and mini-bulbs. One type of halogen lamp gets its name from the hockey puck, because of its shape. The flat profile of puck lights make them well suited to under-cabinet applications. Other shapes are much the same as incandescent bulbs. Like incandescent bulbs, halogen bulbs burn hot. Many jurisdictions have banned the use of halogen because this type is no longer considered energy saving.
Halogen lamps offer greater efficiency than incandescent lamps and have more precise beams and whiter color, closer to sunlight. The PAR lamp shown is suited to recessed can lights and works on 120V. Other lamps require a transformer to step the voltage down to 12V. MR lamps are suited to track lights, while the bi-pin, mini-can, and puck lamps work well in under-cabinet installations.
Xenon
Xenon bulbs are a more recent invention than halogen and, though more expensive initially, last much longer. Although halogen is dependable, the bulb still uses a filament that eventually burns out; xenon bulbs, however, use only gas and electricity, allowing them to last two or three times as long. Originally developed as brighter lights for auto headlamps and industrial applications, xenon lamps now offer residential designers new lighting opportunities. Xenon lamps contain two electrodes in an extremely small tube filled with inert gases. Electrical current arcing between the electrodes yields a bright light with a color resembling sunlight. The real plus is the lamp life, rated at around 20,000 hours—long enough to last a typical under-cabinet installation for 50 years. Xenon bulbs dissipate their heat more efficiently than halogen, hence they run cooler. Xenon lamps are miniature size with pin bases. Fixtures for under-cabinet or display case applications include strips with lamps mounted at 4″ or 6″ (102 or 12 mm) apart as well as individual lamps that can mount at any spacing. Transformers are required to convert alternating current to 10V or 12V direct current. Many jurisdictions have banned the use of xenon because this type is no longer considered energy saving.
Small strip fixtures with xenon or halogen mini- bulbs are well suited for under-cabinet installations. The fixture shown uses 5w, 24v xenon mini-bulbs spaced about 2″ (51 mm) apart.
Light-Emitting Diode (LED)
Light-emitting diode (LED) lamps produce light by a solid-state, in which electrons move through a semiconductor material. This technology is the latest lighting innovation to join the energy-efficient options available to designers. LEDs are the costliest initially but save over their lifetime, which is up to 50,000 hours. LEDs contain no mercury so they are a “greener” product than fluorescents. And, with no filament that can be broken, they are more durable than other bulbs. They can be manufactured in very small sizes, which make them good candidates for certain kitchen and bath applications, such as accent and under-cabinet lighting. LEDs are ideal for uses subject to frequent on/off cycling, unlike fluorescent lamps, which fail faster when cycled often. LEDs can be dimmed very easily. Whereas incandescent and fluorescent lamps often require an external reflector to collect light and direct light beams in a usable manner, the solid package of the LED can be designed to focus its light.
LED technology continues to evolve, producing long-lasting and energy-efficient lighting products, such as shown here. The 6W spotlight contains three diodes in a bulb only 2-inch (51 mm) high. The strip fixture, intended for under-cabinet lighting, contains clusters of very small diodes.
Other than their initial expense, LED bulbs have other downsides compared to other types. LED lighting fixtures are integrated systems in which the light sources (LEDs), the fixture housing, and the primary optics are inseparable. The integrated systems contain heat sinks to dissipate the heat. For this reason, they can’t be enclosed in separate fixtures. Also, the quality of LED light may not be optimal for some applications. They have a high color temperature and poor color rendering index, however this is continually improving.
LED lamps produce a lighting color of white or warm white with very little heat. LED bulbs range from small to very small and available in A, PAR, MR shapes, which screw into standard 120V sockets. LED mini-bulbs work off transformers and are mounted in clusters in fixtures for under-cabinet installations. This technology is advancing rapidly, and additional products are sure to evolve in the future.
Built-In Lighting
Getting light to the desired target requires not only a lamp, but also a device that houses the lamp and controls its beam. Lamps can either be built into cabinets or other parts of the home structure or enclosed in manufactured lighting fixtures also called luminaires. Built-in lighting uses a site-built structure to focus or diffuse the light (see Figure 20.8). Some typical applications for built-in lighting are described next.
- Under-cabinet lighting. Lamps mounted under wall cabinets near the front edge throw light directly on the countertop where it is most needed for food preparation. Lamps suited for this use include fluorescent tubes, halogen or xenon puck lights, xenon strips, and LED strip fixtures.
- Above-cabinet lighting. The same types of lamps suited for under-cabinet lighting can mount on top of wall cabinets to bathe the ceiling in light for ambient lighting.
- Coves and valances. Horizontal baffles running around the room below the ceiling can hide strip lighting, usually fluo-rescent tubes, for soft, ambient room lighting. A light cove directs light upward onto the ceiling, which reflects it back down in a diffuse pattern. It works best when the ceiling is painted flat white or off-white. A valance is a similar baffle but open at top and bottom to allow the light to wash both the ceiling and the wall below.
Lighting can be built into the structure or cabinetry to illuminate any selected surface and disperse light directly or indirectly. Direct light, such as shown in the under-cabinet application at left, brightens a countertop. Indirect lighting, shown in the other two examples, creates a softer effect for ambient lighting.
Lighting Fixtures
Manufactured lighting fixtures come in an amazing variety that is constantly changing. Previously available only in bound volumes, data relating to these fixtures are increasingly accessible online. The primary types of residential lighting fixtures are described briefly next.
Surface-Mounted Ceiling Fixtures
Mounting the light source on rather than in the ceiling enables it to throw light in all directions, an asset when designing ambient lighting. Several fixtures arrayed around the edge of a room are likely to be more effective than a single one in the center of the room. Surface fixtures come in single or multiple configurations as drums, cones, squares, and spheres and accept any of the lamp types previously discussed. Manufacturers’ specifications state whether they can be dimmed and the maximum wattage permitted to avoid fire hazard.
Recessed Fixtures
Burying a fixture into the ceiling makes it create the effect of a spot of light coming through a hole in the ceiling. Recessed fixtures offer many designs for getting the light into the room. You can choose between units that hold the lamp in a fixed position or units with the lamp mounted in an “eyeball” that swivels. Some fixtures come with reflectors built in (Alzak type), and take an A-type lamp. Others have corrugated baffles painted white or black. White baffles direct more light downward but are harsher to look at.
Recessed fixtures generally throw a cone-shape beam to illuminate a limited area. A single recessed fixture in the center of a room wouldn’t light up the whole room, as would a pendant or surface-mounted one that delivers light in all directions. Thus, recessed fixtures are best installed in multiples, spaced 24-inches to 48-inches (610 mm to 1 220 mm) apart. To determine the best spacing for a particular fixture, get the angle of the beam spread from the manufacturer, then position fixtures so that the beams overlap at the intended target. For example, if you are using recessed fixtures to light up a countertop, you want the beams to overlap at a height of 36-inches (910 mm).
Recessed fixtures give off a lot of heat. The National Electrical Code requires a separation of at least 1/2-inch (13 mm) between the fixture and any combustible material and a separation of 3-inches (381 mm) from any insulation, unless a type IC housing is specified, which may abut any combustible material or insulation.
Suspended Fixtures
Hanging a fixture from the ceiling brings the light source down into the room for more intimacy, particularly in dining areas. These types of fixtures include track lighting, chandeliers, pendants, or any other fixture that is suspended from the ceiling.
Chandeliers are the descendants of the elaborate assemblies of candles that hung from castle ceilings. Today’s versions retain some of the effect with multiple flame-shape or other mini-bulbs that mimic the light of candles. Pendants are a less formal modern adaptation of the idea that hold one or more lamps. Some pendants direct light evenly in all directions. Others focus a beam upward or downward down. Wiring the fixture to a dimmer switch enables diners to adjust the lighting level to suit the mood of the meal. These fixtures are typically installed between 30-inches and 36-inches (760 mm to 910 mm) from the work surface or table; however above a kitchen island it is not uncommon for the fixture to be planned at 48-inches (1 220 mm) above the surface so the fixture does not block the users view into another area.
Track lighting is a fixture that slide in tracks make it possible to add or reposition the fixtures. They afford even more flexibility because the fixtures swivel and rotate. This versatility enables track lights to wash walls and illuminate countertops or artwork. The tracks mount on the ceiling or hang from legs, if the ceiling is high enough. Individual lamps insert into the track and make contact with two conductors, mounted in parallel inside the track. Lamp housings can be cans with or without baffles and reflectors, much the same as for recessed fixtures. Lamp types used also vary, although many designers favor lamps with built-in reflectors (PAR or MR).
Wall-Mounted Fixtures
After the fixtures, cabinets, and mirrors are located in the design, kitchens and baths tend to have little free wall area for wall lighting fixtures. Still, there may be areas where a wall-mounted fixture makes sense. Sconces are single-bulb fixtures that throw light out, up, down, or a combination of these, based on the design of the diffuser lens, baffle, or reflector housing. They can mount on the wall surface or be recessed.
Another type of wall-mounted fixture is strip lighting, which may be an array of individual lamps mounted into a strip base or a single fluorescent tube with a diffuser lens. Multiple-lamp strips take A, G, or mini-lamps. Tube strips take fluorescent lamps of various lengths, from 16-inches to 48-inches (406 to 1219 mm) or arrays of other lamp types. Strip lights are well suited to baths, as we discuss later under “Vanities and Lavs.”
Lighting in Kitchens
Providing good lighting in the kitchen is probably more difficult than any other space in the house. Food preparation surfaces need adequate task light of the right color and intensity. The rest of the room needs ambient light for general illumination. If a dining area is part of the kitchen, it should be lighted with a source that fosters enjoyment of the meal. All of these goals can be met with proper lighting strategies.
Food preparation is a demanding task that requires good task lighting that puts light on the work surfaces, most of which are on countertops around the periphery of the room. In the quest for economy, many mass-produced houses light the entire kitchen with a single fixture in the center of the ceiling, with the worst possible results guaranteed to cast the cook’s shadow on any work surface not directly under the fixture. A much better approach is to locate fixtures at the ceiling just in front of the wall cabinets or under the wall cabinets themselves. Ranges can be lighted with lights built into range hoods. Any custom-designed range hood should contain adequate lighting. For downdraft ventilating ranges, mount a recessed or surface-mounted fixture above the range.
The best location for countertop lighting is below the wall cabinets, with the fixtures mounted near the front edge. Lamps mounted here throw their light directly on the work surface, with no objects intervening to cast a shadow. Fluorescent lamps mounted end to end work well if the lamps have a color temperature above 3500K. Another option is a strip fixture that contains several halogen, xenon, or LED lamps clustered or arrayed in a series.
A good balance between ambient and task lighting can be had by combining under-cabinet fixtures with fixtures mounted on the ceiling.
The countertop also can be lighted from the ceiling by locating the fixtures close enough to the wall so that they won’t cast the user’s shadow on the countertop. Be sure that enough clearance is left to enable wall cabinets doors to open. Fixtures can be recessed or surface mounted on the ceiling or recessed into an overhanging soffit. Can lights and spots work well at the ceiling level. If mounted in tracks, they enable the homeowner to adjust their location and focus.
Another approach mounts task lights in a soffit/bulkhead in front of the wall cabinets.
Task lighting can be supplied by track lighting in front of the cabinets, which enables users to adjust the location and beam of the lighting. The fixtures must be chosen and installed to allow the cabinet doors to open.
Successful ambient lighting provides evenly distributed light that doesn’t cause glare or discomfort. A single fixture in the center of the ceiling, mentioned earlier, may satisfy the first need but not the second. Anyone sitting in the room can’t look up at the ceiling without squinting. If a single fixture is the only choice for ambient lighting, one that bounces light off the ceiling gives a better result. Better still is to use more than a single source, such as strips or individual fixtures mounted on the tops of the wall cabinets.
If a dining area is included as part of the kitchen—on an island or separate table—it should be lighted with a source that provides enough light to see the food and to suit the desired mood, which can change. A breakfast eaten quickly on a dark morning needs a different quality light from a fancy dinner intended to be enjoyed in a relaxed atmosphere. An oft-chosen answer to this is a pendant centered over the dining surface. Another possibility is surface-mounted or recessed cans. If there is a wall surface, a sconce might work. In any case, the fixture should be connected to a dimmer switch, so that the lighting level can be adjusted. Some fluorescent lamps cannot be dimmed. For relaxed dining, the cabinet lights can be turned off, allowing the dining surface to be the focus.
A kitchen that includes a dining area needs a light source above the dining surface, such as the pendant fixture shown here. In this example, the strip lighting under the cabinets can be turned off during dining, while the indirect lights above the cabinets can be dimmed, as desired, for the mood.
As kitchens become a space for living as well as food preparation, they often include areas that display art, china, or collectibles. Wall-mounted art can best be lighted with adjustable fixtures mounted on the ceiling at a distance out from the wall of 24-inches to 30-inches (610 mm to 735 mm). Another solution is recessed ceiling fixtures. Eyeball-type fixtures that rotate in their housing allow the direction of the light to be adjusted.
Guidelines for using track lighting to illuminate objects on a wall, the wall itself, or any vertical surface. Courtesy of the American Lighting Association
Guidelines for using recessed fixtures for accent lighting. Matching the lamp type correctly with the vertical and horizontal distances shown will ensure light levels of 20 to 60fc at the center of the beam.
Lighting for china and other items displayed behind glass doors can be provided by small, low-voltage strip lighting, such as xenon or LED strip fixtures, mounted at the top of the cabinet just behind the door.
Lighting in Baths
The 5-foot by 7-foot (1.524 m by 2.134 m) bath that was the standard in production housing of past decades often made do with a single ceiling fixture for ambient lighting and possibly another fixture above the lav for task lighting. As baths grow in size and amenities, they require a different approach to lighting. For one thing, a larger bath may not be just one room but a room with several subrooms to enclose tubs, showers, or toilets—each needing a source of light. So the goal, once again, is to deliver lighting where it is needed.
The space between the lav and the wall is one of the most critical but least forgiving areas for bathroom lighting. People have to be able to see the lav or vanity as well as themselves in the mirror above. To do this, the fixture must illuminate the person’s face. The simplest solution is a fixture above the mirror. This is also the worst location, since the fixture throws light downward onto the person’s face, causing shadows below the eyebrows, nose, and chin—just what you don’t want when shaving or putting on makeup. A much better approach is to locate sconces or—better—strip lighting at the sides of the mirror, where they can light the face more evenly. Two fluorescent tubes mounted behind a valence above the mirror can also work by bouncing light off the wall before it hits the person’s face. But to work, the wall must be white or near white, and even then this lighting choice might not be as effective as side-mounted fixtures.
Fixtures mounted at both sides of a mirror are the most effective way to spread light where it is wanted on the user’s face. This may provide all of the light required in a small bath. Larger baths may require additional fixtures for task or ambient lighting.
Task lighting at a vanity can be provided by a fluorescent strip fixture mounted behind a valance.
A pleasing and economical way to illuminate the small subspaces of a bathroom is directly through their walls. Glass block or obscure (patterned) glass in these walls enables the enclosed space to borrow light from the main space. If this isn’t feasible, these spaces usually can be well lighted with a single ceiling fixture, recessed or surface mounted. Many exhaust fans contain a lamp. A separate lighting fixture over a wet area should be a water-resisting type.
Your client may want a heat lamp in the bath. If you include one, locate it in the ceiling above an open area with enough room for the per-son standing below it to move about. Because heat lamps consume a lot of electricity, they should always be switched separately from other fixtures.
Adequate light levels at the mirror and bathing areas may be all that is needed in a bath. A larger room may require additional ambient light in the form of recessed ceiling fixtures or wall sconces.
Natural Lighting (Daylighting)
Sunlight can make any kitchen and bath a space pleasant to be in. Skillful use of daylighting can provide the ambient lighting required in a kitchen or bath and often all of the task lighting. The light itself is free, and putting it to use in a new home can likely be done within the budget. And even if it costs a bit more in remodeling projects, the result is often worth it. Some ways to incorporate and optimize daylight-ing in a room are described next.
Windows in an outside wall are a good source of daylighting as well as ventilation—an asset in both kitchens and baths. Their type, size, and placement must coordinate with the equipment and fixtures in the room and—in baths—accommodate the need for privacy.
A window on an outer kitchen wall opens the room to a view of the outside, floods the room with ambient lighting, and illuminates the work surfaces. However, the same wall is a natural site for wall cabinets. Fortunately, there are other storage options available, such as sepa-rate pantries, tall cabinets, and base cabinets.
Bath windows should be sized and situated to afford privacy. Although any window can be treated with blinds or shades to control view, a narrow window mounted with a sill at least 54-inches (1 372 mm) above the floor will naturally shield occupants adequately from view from the outside.
Kitchens and baths in one-story homes or on the top floor of multistory homes may be candidates for daylighting via an opening in the roof. A skylight or roof window, centrally located, can illuminate a wide area, providing task lighting on work surfaces as well as ambient lighting for the room.
Kitchens use to be isolated from the rest of the house. The current design trend for making the kitchen serve for social interaction as well as meal preparation also opens the kitchen to light from adjacent rooms, or borrowed light.The openings between rooms may be full height for circulation or smaller to promote a sense of openness and to bring in daylight borrowed from the next room.
Successful lighting design in any interior space requires adequate light of the right color and distribution for three different purposes. Am-bient lighting provides illumination for the entire space. Task lighting directs a focused and controlled amount of light on a particular work surface. Accent lighting illuminates certain selected objects.
Kitchens and baths require ambient and task lighting and often accent lighting. A good design begins by taking advantage of daylight through windows, skylights, or openings to other rooms before considering artificial lighting, which can be provided by a wide variety of fixtures and lamps. Lighting fixtures can be selected to control the direction, distribution, and amount of light delivered, while the lamps themselves can be selected for size, shape, light color, and energy use. Incandescent lamps are being phased out. Their replacements are newer types that last longer and use far less energy.
Task lighting on kitchen work surfaces can come from fixtures mounted under wall cabinets, in soffits above the cabinets, or from ceilings. Pendent or ceiling fixtures can provide controlled lighting for dining surfaces. Many possibilities exist for ambient lighting.
Lighting for baths requires task lighting at mirrors, ambient lighting for the entire room, and often special lighting for showers and other enclosed spaces.