Making the Appropriate Lamp, or Light Bulb Selection
A “lamp” is the term used in the lighting industry to describe what is most commonly called a light bulb. The key to lighting energy savings lies in the choice of lamp that we use.
There are three primary families of lamps, or bulbs:
Incandescent bulbs have historically been the most frequently used in residential applications due to their low initial cost. Incandescent sources, however, are relatively inefficient in their conversion of electrical energy to visible light and can therefore add unnecessary electrical costs to our electric bills.
Fluorescent and High Intensity Discharge bulbs have been used most often in commercial and industrial applications. Their initial cost is more than incandescent lamps, but they are much more energy-efficient and last significantly longer.
Due to major improvements over the last few years in the color rendering abilities of fluorescent bulbs, and the availability of small fluorescent bulbs called “compact fluorescent lamps” or “CFL’s”, fluorescent lamps are now a very viable alternative to incandescent lamps for home lighting use. As an example, for the same amount of electrical energy, compact fluorescent bulbs produce 3-4 times more light than an incandescent bulb.
Incandescent lamps are the least expensive to buy but the most expensive to operate. Incandescent bulbs also have the shortest lives of the common lighting types. They are also relatively inefficient compared with other lighting types.
The three most common types of incandescent bulbs are:
- standard incandescent
- tungsten halogen
- reflector lamps.
Known as the “A-type light bulb,” these lamps are the most common yet the most inefficient light source available. Note that a larger wattage lamp or bulb may not be the most energy- or cost-effective option, depending on how much light is needed. “Long- life” bulbs, with thicker filaments, are a variation of these A-type bulbs. Although long-life bulbs last longer than their regular counterparts, they are less energy efficient. The best option to achieve energy-efficiency is to replace “A” bulbs with compact fluorescent bulbs, which will be discussed below.
This newer type of incandescent lighting achieves better energy efficiency than the standard A-type bulb. These bulbs are more expensive than standard incandescents but can have significant impact on achieving greater light output than standard incandescent bulbs.
Reflector bulbs and Parabolic Aluminized Reflector bulbs
Reflector bulbs (Type BR) are designed to spread light over specific areas and are used mostly in recessed downlight fixtures, track lights, and other aimed or directional lighting applications.
Parabolic aluminized reflectors (Type PAR) are an excellent replacement for the BR bulbs. They have a specially designed reflector that is highly efficient in pushing light into the space.
Fluorescent lighting is used mainly indoors, both for general/ambient lighting and task lighting, and is about 3 to 4 times as efficient as incandescent lighting. Fluorescent bulbs last about 10 times longer than incandescents. To gain the most efficiency, you should install fluorescents in places where they will be on for several hours at a time.
You can also increase the energy savings for existing fluorescent lighting by replacing them with a more efficient model (providing a lower wattage but approximately the same light output), or by replacing the existing fixture with a more efficient model.
Compact fluorescent lamps (CFLs) are the most significant lighting advance developed for homes in recent years. They combine the efficiency of fluorescent lighting with the convenience and popularity of incandescent fixtures.
CFLs can replace incandescents that are roughly three to four times their wattage, saving up to 75% of the initial lighting energy. Although CFLs cost from 5 to 10 times more than comparable incandescent bulbs, they also last 10 to 15 times as long. This energy savings and superior longevity make compact fluorescent lamps an excellent choice for residential use.
As previously discussed, CFLs are one of the best energy efficiency investments available. When introduced in the early- to mid-1980s, CFLs were bulky, heavy, and too big for many incandescent fixtures. However, newer models with lighter electronic ballasts are only slightly larger than the incandescent bulbs they replace. The new CFLs also produce a better color for the home.
High-intensity discharge (HID) bulbs provide the highest effectiveness and longest service life of any lamp type. They are commonly used for outdoor and street lighting, but have very limited applications in homes. Their residential use is limited to outdoor lighting for driveways, backyards, etc.
Light Emitting Diodes (LEDs) produce light when voltage is applied to negatively charged semiconductors, causing electrons to combine and create a unit of light (photon). In simpler terms, an LED is a chemical chip embedded in a plastic capsule. Because they are small, several LEDs are sometimes combined to produce a single light bulb.
LED lighting in general is more efficient and longer lasting than any other type of light source, and it is being developed for more and more applications within the home. LEDs are currently popular in under-cabinet strips and some types of downlights. LED is a relatively new technology that continues to advance at a rapid pace, with the ongoing introduction of many new applications and options.