Fundamentals on the energy and cost savings opportunities provided by fluorescent lamps

The basic design of fluorescent light bulbs. A fluorescent light is a sealed glass tube bulb that contains a small amount of mercury and some type of gas, such as argon, as well as phosphor powder. A compact fluorescent contains, for example, an average of 5 milligrams of Mercury - roughly the equivalent to the tip of a pen. When you are looking at these tube-shaped bulbs, you notice that there is one or two electrodes on each end. These contact pins wire to an electrical circuit that connects to an AC (alternating current) supply. While there are many technical details in the inner operation of the lamp, basically, when the lamp is "on," an electrical current flows through ionized gas.

A fluorescent ballast is designed to control the flow of AC current in the light. Ballasts are essential because they manage the lamp's operation and prevent blow outs that could result from an ever increasing flow of current. While they can't stop changes in current, they are capable of slowing the changes. There are two types of ballasts: magnetic and electrical. Magnetic ballasts have relatively low cycle rates (with resultant flicker), and they may vibrate (resulting in an audible hum). Electronic ballasts provide more precise current flow regulation. These generally don't create either flicker or humming as they cycle at a higher rate. The most modern of lighting designs for business and industry utilize electronic, though there are various tube designs requiring specialized ballasts to accommodate the specific current and voltage levels their usage requires.

various tube designs requiring specialized ballasts



Benefits of using fluorescent light bulbs.  When compared to standard incandescent lights, fluorescent lighting has been found to be far more efficient and, overall, cost less to operate. Operation cost takes into account not only the price to purchase the bulb, but the bulb's lifespan (meaning how often it has to be replaced), the labor cost to replace lights, as well as less cooling costs which result from the bulbs running cool rather than hot and throwing off less heat when in operation. Life span ratings on the various bulbs range from 6,000 to 24,000 hours, based on the industry standard of a three hour burn per start. Replacing bulbs that are used most often is the way to start gaining the most financial savings quicker.

The environmental impact of fluorescent light bulb use. Modern fluorescents provide energy saving solutions and reduce emissions harmful to the environment. Information provided by the ENERGY STAR website states that products qualified with the energy star symbol, for example, ""use at least 2/3 less energy than standard lighting, generate 70 percent less heat, and last up to 10 times longer."  The site also states that each qualified compact fluorescent light (CFL) used prevents over 450 pounds of emissions from power plants.  The Mercury contained within the bulbs are not released during normal usage, and are safe for use in home or office. However, care must be taken not to break the glass tubes or forcefully remove the lamp from packaging or when installing or replacing the bulbs. Also, these bulbs should not simply be thrown away into normal garbage. Better options exist:

Disposal of CFLs. Fluorescents require special disposal because they do contain Mercury. They should never to sent to an incinerator. It's also not recommended to simply place them in the trash receptacles. Most local waste management agencies have special programs set up for their disposal in your community, so it's best to contact your agency. The GE Consumer and Industrial Lighting site suggests that, if your community disposal company does not yet have a special program set up to handle these bulbs other than to place it into your regular garbage, first place the bulb(s) in a strong plastic bag and seal the bag before placing it in the trash. If you drop or break a bulb in your home: (a) Sweep instead of vacuuming all the glass fragments and particles, (b) place all broken pieces in a sealed plastic bag, (c) wipe the area with a damp paper towel and (d) place those towels in the sealed bag also; (e) open windows for ventilation.

The impact of a fluorescent ballast on energy savings.  An electronic fluorescent ballast is key to energy savings for two reasons: first, their rate of operation is more controlled; second, electronic fluorescent ballasts operate at cooler temperatures, compared to magnetic ballasts, and can thus reduce office cooling costs. However, there are methods to improve the efficiency of ballast systems, both magnetic and electronic and the newer, most energy-efficient models are designed using techniques to impact efficiency. (Efficiency is measured in lumens per watt.). Those engineering techniques include:

  • reducing energy lost in ballast operation.

  • operate the lighting system using high frequency lamps.

  • reduce losses from lamp electrodes.

Sample lamp data. Here are just a few examples:

  • In general, compact fluorescent light bulbs (which would include CFL bulbs such as a 13 watt, 18 watt, 20 watt, 30 watt and 55 watt) provide energy savings of up to 75% compared to incandescents of comparable light output.

  • A T8 tri-phosphor bulb is 20% or more efficient than a standard T8 bulb. It boasts an average life of 20,000 hours, cool operation, and a Color Rendering Index (CRI) of 75 (on a scale of 100 for truer color). This bulb is used in our panel mounting Ambient Lamps, for one example.

  • A T5 high output lamp produces 45% more initial lumens (light output) than a standard T5, has an average life of 16,000 hours, cooler operation than comparable halogens and incandescents, and a Color Rendering Index (CRI) of 85 -- making it the most color accurate fluorescent bulb source available at this time. These bulbs are used in our Office Panel Light, for one example.

Opportunities for consumers and corporate purchasers. It doesn't matter whether you are considering task lamps, ambient lamps, or overhead fixtures or bulbs for your home lamps, lighting is one area in which the buying decision can have a big impact on the business bottom line, personnel comfort, and environmental sustainability.