General Benefits and Savings
Careful selection of the light most suited for a given application yields many of the following benefits attributable to fluorescent lights:
- Less power used
- Reduced heat load on air conditioning systems
- Better light distribution
- High Color Rendering Index (85-90+) giving excellent color definition
- Low lumen (light) depreciation over the life cycle (less than 10 percent)
- Long life (15,000-20,000 hours) giving lower lamp replacement costs (less lamps lasting longer)
- Better color appearance as indicated by the Color Rendering Index which influences the users’ psychological perception of a space and occupants.
CFLs can replace incandescents that are roughly 3 to 4 times their wattage, saving up to 75 percent of the initial lighting energy. Although CFLs cost from 10 to 20 times more than comparable incandescent bulbs, they last 10 to 15 times as long. This energy savings and superior longevity make CFLs one of the best energy efficiency investments available. CFLs can be installed in regular incandescent fixtures, and they consume less than one-third as much electricity as incandescent lamps do.
An energy-efficient lighting retrofit reduces both lighting and cooling costs. On hot summer afternoons, many utilities experience periods of increased demand for power to cool buildings, and the utilities charge customers a premium during these peak periods. A low-cost lighting retrofit is one strategy for reducing the amount of expensive peak electricity a building consumes.
Commercial and Local Government Facilities
Lighting is the single largest electricity user in commercial buildings. In 1990, lighting consumed 39 percent of the electricity used in U.S. commercial buildings. Energy-efficient lighting is one of the most cost-effective options available to local government officials for reducing energy costs in their buildings.
Local government officials looking for ways to save money should consider retrofitting their existing facilities with energy-efficient lighting. Of course, you may also realize greater savings by requiring use of energy-efficient lighting in new buildings. And don't overlook the savings you can achieve by retrofitting street lights for greater energy efficiency.
Energy-efficient fluorescent lamps, for example, save 15-20 percent of the wattage used by standard fluorescents (T12-type) and last just as long. Although the efficient lamps (T8-type) are more expensive than the T12 lamps, the energy savings more than compensate for the extra cost. T8 lamps are a popular choice to replace conventional T12 lamps, because they provide 98 percent as much light as do standard lamps and use about 40 percent less energy when installed with an electronic ballast.
When replacing standard fluorescents with efficient T8 lamps, it is necessary to replace the existing ballasts with electronic ballasts. Electronic ballasts operate at higher frequencies than do conventional electromagnetic ballasts, so these lighting systems convert power to light more efficiently. They also operate 75 percent more quietly than do conventional electromagnetic ballasts, eliminating the familiar flicker and hum of older fluorescent lights.
Overall T5 Benefits – There are a number of energy, ESD and other benefits associated with the use of T5 lamps compared with the T8 type. These include:
- Improved lumen depreciation (97 percent versus 93 percent), hence less frequent lamp changes
- Higher efficiency – 96-104+ lumens/watt versus around 90 lumens/watt for T8 taking into account lamp and ballast)
- Higher operating temperature (35oC v 25oC) better suits likely fitting ambient temperature
- Improved color rendering, 85-90+ CRI;
- Shorter metric size suits modern metric ceiling grids, less waste, better aesthetics
- Suitable for continuous dimming enabling effective daylight substitution
- 40 percent less glass used in construction
- Recyclable with 70 percent less mercury content (3mg instead of 10mg)
- Smaller luminaires with less material
- Less paper used in packaging
Hence the T5 lamp is the most efficient and ESD friendly general-purpose fluorescent lamp available in the market. However, there are other factors to take into account:
- Lamps are currently more expensive, so attention needs to be given to the payback period as well as to the above ESD advantages
- Even the standard, High Efficiency (HE) T5 lamp is significantly brighter (+50 percent), so high quality design, optics, and materials are needed in the reflector and diffuser to avoid flashings, glare and iridescence
- Lamps are shorter and so are not always suitable for retrofitting to T12 or T8 sized fittings
Other Benefits of Low-Cost Lighting:
- Saving money on energy, although important, isn't the only advantage of an energy-efficient lighting retrofit. Saving energy reduces pollution from electricity generation. For example, replacing one 75-watt incandescent lamp with an 18-watt compact fluorescent lamp prevents the emission of 1 ton (0.9 metric tonnes) of carbon dioxide and about 20 pounds (9 kilograms) of sulfur oxide from a coal-fired power plant.
- Efficient lighting systems that replace standard fluorescents also boast more accurate color and less glare, which may increase worker productivity. Studies have suggested that high-frequency lighting can reduce the incidence of eyestrain and headaches among employees.
- A lighting retrofit results in lower utility and maintenance costs, which can also raise the market value of a building and provide an edge in competitive leasing markets. Energy-efficient lighting in new buildings on retrofits is a winning strategy. Local governments save a substantial amount of money in reduced energy costs, utilities reduce electrical demand (and the need to build expensive new power plants to meet that demand), and, when standard fluorescent lighting systems are replaced, employees enjoy adequate lighting without noise, flicker, and color distortion.
Residential Buildings
Benefits in residential buildings include:
- Lower utility bills – Installing high-efficiency lighting in the most used fixtures in a home will reduce lighting energy consumption (and costs) by half.
- Improved comfort – Greater efficiency in lighting translates into less waste heat to be removed from the space by air conditioning equipment.
- Improved safety and security – Energy-efficient outdoor lighting technologies can improve the safety and security of a home. Safety can also be improved by eliminating high-wattage light bulbs that are fire hazards.
- Improved convenience – CFLs last at least 10 times longer than incandescent light bulbs, resulting in fewer lamp replacements. Lighting control devices improve convenience by eliminating the need to manually flip a switch.
- Improved quality – Technological advances in fluorescent lighting have produced fluorescent lamps that are essentially equivalent to incandescent lamps for color quality and instant start.
