Frequently Asked Questions (FAQ)
Q. What is an "Environmentally Friendly" fluorescent bulb?
A. Environmentally Friendly fluorescent lamps are designed to meet the Federal Toxicity Characteristic Procedure (TCLP) criteria for classification as non-hazardous waste in most states. (Regulations may vary. Check your local and state regulations.)
Q. What does CRI mean?
A. The new generation of fluorescent products are rated by CRI (Color Rendering Index) and by color temperature (in Kelvins). CRI rates a fluorescent lamp's ability to render color as accurately as incandescent light or natural daylight, with 100 representing the top of the scale.
Q. What is Kelvin?
A. Kelvin color temperature refers to the tone of the light. A lamp that produces light for example in the 2700K range is similar in color to an incandescent lamp: warm and inviting. Other color temperatures – 3000K, 3500K, 4100K, 5000K, and 6500K – are made to work in specific environments for mood and color matching.
Q. What is Energy Star?
A. Energy Star® is a government-backed symbol fore energy efficiency, jointly managed by the U.S. Environmental Protection Agency (EPA) and the U.S. Department of Energy (DOE). The label was created to help consumers easily identify products that save energy and help to protect the environment.
Energy Star manufacturer partners may place the label on products that meet the high energy efficiency guidelines of the program. To keep up with technological advances, Energy Star reviews the guidelines for each product category.
Q. What is a Halogen?
A. Halogens are five non-metallic elements found in Group 7 of the periodic table. The term "halogen" means "salt former" and compounds containing halogens are called "salts."
The halogens are: Fluorine (F), Chlorine (Cl), Bromine (Br), Iodine (I) and Astatine (At).
The basic design of the incandescent lamp has not changed much since the late 1800s, when Thomas Alva Edison successfully produced the first operational electric light bulb. These are the must-know fundamental facts about incandescent lamps and the alternative choices that are available today.
Incandescent lamp filaments are made of tungsten. Tungsten is a metal that can operate at very high temperatures without evaporating too quickly and resulting in early lamp failure. Incandescent filaments only convert about 10 percent of energy used into visible light, so it is necessary to use a material that can withstand extremely high temperatures. Most lamps use a coiled filament design, which has been found to be stronger and deliver better performance.
The Glass Bulb
The filament inside an incandescent lamp must be protected so that oxygen does not reach it and cause it to evaporate on contact. Most incandescent lamps are either vacuum-sealed or gas-filled. It was discovered in the early 1900s that the introduction of gas inside the bulb, or envelope, created a pressure against the filament. This pressure allowed the filament to burn hotter and last longer. Most gas-filled incandescent lamps today use a mixture of argon and nitrogen gases.
The size and shape of a lamp’s bulb are designated by letter(s) and a number. The letter specifies the shape of the bulb and the number indicates the maximum diameter in 1/8-inch increments. Example: A G40 is a globe shape which is 5 inches in diameter.
How it works
Just as a piece of metal being blacksmithed or the molten glass at the end of a blower’s rod heats to a brilliant glow, so does the filament of an incandescent lamp. The difference is that electricity is used to heat the filament instead of fire. This phenomenon is known as incandescence.
Screw-type bases used on incandescent lamps consist of three components: the threaded screw section, the glass insulation ring and the contact disc. The lead wires which exit the glass bulb of the lamp are attached to the base at two points. One wire is soldered to the bottom of the contact disc and the other to the top edge of the screw section. The glass ring acts as an insulation barrier between the two points. This assembly completes the circuit and the lam p is electrified once the base is screwed into a socket and the contact disc touches the center point of the socket.
The base itself has nothing to do with the seal of the bulb; it is a separate part of the lamp that is attached with cement. Typically, boxes are made from aluminum or brass. Brass bases tend to perform best due to their compatibility with most socket materials.
Halogen light bulbs operate on the same principle as standard incandescent heating the tungsten filament until it glows but from there, halogens improve upon the process.
How it works
Operation of halogen lamps is based on the ‘Halogen Cycle’. Tungsten particles from the bulb’s filament evaporate. The evaporated tungsten collides with the halogen gas. The particles chemically bond with the halogen gas. Tungsten is then redeposited back to the filament and the gas is re-released.
The operating temperature is a significant factor to ensure that the halogen cycle performs properly. The interior wall of the bulb must be above 250 degrees Celsius and less than 1,100 degrees Celsius. Additionally, the filament of the lamp must reach at least 2,000 degrees Celsius. To reach this temperature, the interior wall must be in close proximity to the tungsten filament.
Benefits of halogens
Halogen lamps offer a combination of benefits that make them an appealing alternative to standard incandescents in many applications.
Halogen lamps deliver a crisp, white light. Not only is the quantity of the light greater than a standard incandescent of comparable wattage, but the quality of the light creates a higher contrast for reading and other tasks. This also makes halogen perfect for display accent and general lighting.
Since halogens are incandescent lamps, their CRI of 100 will render colors accurately and will mate the color temperate of other light sources in the 3000K range.
Standard incandescent lamps and halogen lamps both use tungsten filaments. However, the filament in the standard lamp evaporates over time, causing it to weaken and eventually break. The gasses inside halogen lamps allow the evaporated tungsten to find its way back to the filament and redeposit, ensuring a long life of 20,000 hours or more.
Compared to standard incandescent lamps, halogens offer superior lumen performance throughout the life of the lamp.
While conventional incandescent lamps can be handled with bare hands, halogen bulbs should not. Since the quartz envelope, or bulb, of the lamp reaches high temperatures, the oils and salts from skin will deteriorate and weaken the bulb.
If your hands should come in contact with the bulb, use a small amount of rubbing alcohol and a soft cloth to clean the lamp. Allow time for the bulb to dry before using.
How it works
The glass tube of a fluorescent lamp is filled with a gas containing argon and mercury vapor. The interior wall of the tube is coated with a paint known as phosphor. At each end of the tube, electrodes send electrons throughout the gas causing it to emit ultraviolet light. As the ultraviolet light passes through the phosphor coating, it is converted into a longer frequency to create visible light. The glass tube of the bulb prevents the harmful UV rays from escaping. Fluorescent lamps are more efficient than incandescent lamps because less energy is converted to heat. Instead, most of the energy creates visible light.
The phosphor coating on pioneer fluorescent lamps, called ‘halophosphate’ was a sing-color band phosphor that produced ‘cool white’ light. This light resembles daylight, but it is weak in the green and red part of the spectrum and stronger on the yellows. This imbalance distorts visual perception of color, but for many years the cool white halophosphate fluorescent was the only choice available.
‘Warm white’ and ‘daylight’ lamps improved color for fluorescents. These lamps also used halophosphate, but they were designed to achieve certain effects: ‘warm’ to resemble incandescent light, and ‘daylight’ to create an effect similar to natural light. Still, these lamps fell short in their ability to render colors accurately.
Full spectrum, natural and deluxe represent just a few lamp types that improved fluorescent color performance over the years. However, each type usually sacrifices light output.
Compact Fluorescent Basics
The biggest misconception that still stigmatizes fluorescent light sources pertains to their color rendering. Many consumers still associate fluorescent with having an unflattering green cast. They are probably thinking of products they’ve seen at the cool end of the spectrum, or fluorescent lighting in institutional settings.
The Color Rendering Index is a rating scale up to 100 that rates a light source's ability to accurately convey true color. Light sources with a low CRI will make objects and skin tones appear washed out and dull. Lamps with high CRI ratings bring life to a subject and make colors more vivid. Many CFL’s have CRI ratings that exceed 80, which is a considered excellent.
Lamp color, on the other hand, is based on a color temperature scale with a measurement called Kelvin. A warm color of light would be in the 2000K to 3000K range and would make reds, oranges and yellows more dominant. 4000K range would feature more blue or cool tones. The variety of color temperature options and CRI ratings for fluorescent light sources have improved dramatically thanks to advances in the types of phosphors used. You can now your customer can yourself in your best light without sacrificing energy savings.