Types of lamps
While most folks use the generic term “bulb,” the correct term for glass-enclosed balls and tubes is lamp. Lamps come in a variety of shapes and sizes. Incandescent lamps are glass enclosures from which the air has been evacuated and replaced by an inert gas. This protects the filament from overheating, extending its longevity. These lamps require no external control and are connected directly to the home electrical system through fixture sockets. Incandescent lamps are not energy efficient since about 90% of the energy consumed is turned into heat instead of light.
Fluorescent lamps are glass tubes filled with a combination of a low-mercury gas and either argon, neon, krypton or xenon. The interior of the tube is coated with a phosphorescent or fluorescent coating. When the filaments are energized, the mercury vapor is excited, which will cause the coating to glow. Fluorescent lamps cannot be connected directly to the home electrical system, but must have the voltage regulated by a ballast unit. Compact fluorescent lamps, called CFLs, are small versions of the larger tubes; however, they are manufactured with built-in ballasts and can be screwed directly into most lamp sockets. Fluorescent lamps and CFLs are much more efficient than incandescent lamps and have a longer life cycle.
Halogen lamps use a variation of the incandescent lamp technology. These lamps use a tungsten filament that is encased in a glass container, filled with halogen. Their candlepower output is higher than an incandescent lamp, making them more efficient. Halogen lamps are often used in flood light applications. A smaller version is sometimes used in decorative accent lighting.
The most energy efficient lamps available to homeowners are light-emitting diode lamps, also known as LEDs. However, they are also the most expensive. The life cycle of an LED lamp can be as high as 100,000 hours of continuous operation. LEDs are commonly used in night lights and decorative lighting.
Video: Lightbulb Basics
Light fixtures and luminaires
The term “luminaire” refers to the fixtures that hold a lamp. Luminaires typically contain a fixture body and light socket to house the lamp, and they require an electrical connection for power. Luminaires come in a wide variety of styles and are designed for many different uses.
Can lights are recessed lighting fixtures with openings that are installed flush with the ceiling. These are often used in kitchens, and for spotlighting artwork and other decorations.
Track lights are fixtures where an electrified track is installed on a ceiling or wall. Small spot or floodlights are mounted to the track. The design allows these lights to be mounted anywhere along the track. They're often used as bathroom light fixtures over sinks.
Soft illumination can be accomplished with indirect lighting. A fluorescent strip fixture is placed inside a wooden or metal trough, similar to a flower planter, with the lamps pointing upwards. The trough is mounted on the wall, several inches away from the ceiling. The light reflects off the ceiling, giving a soft glow to the room.
Pendant lighting is a single fixture that hangs by a cord, chain or rod. They're usually grouped in multiples, in a straight line, and are often used for kitchen lighting over counters.
Rope lights, made from flexible tubing, bring a festive vibe to both indoor and outdoor spaces. They're also good for under cabinet lighting.
Wattage and intensity
It's a misconception that a higher wattage bulb is a brighter bulb. Because homeowners have dealt with incandescent lighting for many years, it is easy to make this assumption. After all, a 100-watt bulb appears to be brighter than a 40-watt bulb. However, wattage is not a measurement of brightness, but of power consumption. Brightness or intensity is actually measured in lumens. The actual intensity of the lamp is a function of its design, not its wattage. New package labeling shows this information and allows the consumer to make better choices.
A ballasted lamp, such as a compact fluorescent lamp, is able to give off the same intensity as an incandescent lamp, but consumes less power. Homeowners can save money on utility bills by using lamps that consume less power, yet still maintain adequate lighting intensity for their needs.
When replacing a light bulb, it's important to always match the wattage of the bulb to the corresponding fixture. Using a bulb with a higher wattage could cause the fixture to overheat, which could lead to electrical fire.
There are many ways to control household lighting. The wall switch is the most common and is usually installed about 46 inches to center from the floor. In areas where light needs to be accessible from two or more locations, three-way and four-way switches are used. Dimmer switches are also a favorite form of lighting control, allowing the homeowner to adjust the intensity of the lighting easily. Until recently, dimmer switches could not be used on fluorescent lighting. However, recent advances in ballast technology have allowed both tube fluorescent lamps and CFLs to work with dimming switches.
Common methods of outdoor lighting control include photo eyes, motion sensors and timers. Two or more of these methods are often combined. Since fluorescent lighting is not recommended for outdoor use, most of these lights are incandescent or halogen lamps. Photo eyes allow automatic dusk until dawn operation. Motion sensors turn on lights when movement is sensed in their sensing range. Timer lights automatically operate on a schedule determined by the user.
Lighting for home décor
When formulating a home decorating plan, remember to include lighting as a key element. Because of the wide variety of lighting options available, the proper choice not only affects what you see, but how you see it as well.
Obviously, the appropriate amount of illumination is necessary, but the function of the room should dictate that requirement. Many choices today will not only accentuate the beauty of the home, but also generate significant savings on the electrical bill.
A home decorator will try to match the lighting source with the color scheme of the room. Many homeowners do not realize that lighting is also categorized by color temperature. Color temperature is the perceived color of the light and is measured in degrees Kelvin. Warm colors are perceived to have more reds and yellows while cooler temperatures extend into the blue and white ranges.
The color temperature of the lighting will affect the perceived color of the room décor. You can turn to nature for an example of this concept. If you place several differently colored objects in the yard and note their appearance at different times throughout the day, the colors will appear to change. This is a result of the change in color temperature of the light, caused by various factors such as atmospheric filtering.
Light color and rendering
The room’s color scheme should be considered when choosing the lighting color temperature. For example, if the room is decorated with oranges, browns and reds, the lighting should be at the warmer end of the scale. Blues and greens, however, are best illuminated by lighting at the cooler end of the scale. If the decorations include a wide range of colors, the lighting color temperature should fall in the middle of the spectrum. Remember that lumens measure brightness or intensity while color temperature refers to the color-rendering properties of the lighting. It is also good to note that the warmer color temperatures will appear to be less intense than the cooler temperatures.
Room-by-room lighting analysis
Every room in the home has specific lighting needs. You need to consider what the room will be used for as you decide what lighting to use.
Living room: The living room and other casual areas should be illuminated with warmer colors to create a calm and intimate setting ideal for socializing or relaxing.
Dining room: Formal dining areas will also benefit from warmer, less intense lighting. Many people choose to install a dimmer switch for manual manipulation of the room lighting.
Kitchens and home offices: These rooms should be brightly illuminated using bulbs with high lumen ratings. Kitchens will especially benefit from color temperatures in the mid to upper end of the cool color temperature range because it will render colors more accurately, and provide adequate lighting for cooking.
Home offices will benefit from the white or bright white range of the cool color temperatures because it will make reading, writing and other office tasks easier to accomplish by minimizing eyestrain. Other task-oriented areas, such as laundry rooms and workshops, should also use high-intensity illumination at a cool color temperature.
Multi-purpose rooms: Some rooms may require two or more lighting schemes. For example, the bathroom serves several purposes, from bathing to makeup application and grooming. The main, room lighting should employ a warmer color temperature. Grooming tasks might require a more intense light with color temperatures in the white to bright white range.
Hallways and stairways: These areas of the home are often illuminated by warm color lights from the ceiling. You can add motion sensitive lighting along the floor to prevent slips, and install LED night lights to provide additional support.