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​Choosing Energy-efficient Bulbs and FAQs

Where to use ENERGY STAR® CFL and LED bulbs

Where lights are being used for three or more hours a day, a CFL bulb can maximize your energy and money savings.

  • A hard-to-reach socket makes an energy-efficient bulb ideal—it lasts longer, so you’ll change it less.
  • An energy-efficient bulb may be an option when you need a brighter light without exceeding a fixture’s maximum-rated wattage.
  • In dimmable fixtures, only use dimmable bulbs.
  • CFL bulbs are not recommended for motion-sensor fixtures or photo cell fixtures that automatically turn lights on at night. LED bulbs come available with automatic daylight shut-off and motion sensors on some outdoor models.

Choosing an ENERGY STAR qualified CFL bulb

Use the chart below to select the best CFL bulb for your lighting fixture and room type.


Selecting a CFL Bulb



Selecting a CFL Bulb
CFL Color Chart

CFL bulbs give off a different quality of light based on their Kelvin color temperature (K). Use the chart on the right to select the CFL bulb with the correct color for your space.

CFL bulbs use fewer watts to give off the same amount of light. Use the chart below to choose the CFL bulb that has the equivalent wattage to the incandescent bulb you are replacing.

*Chart below assumes average 10,000 hours at $.09 kWh (9,000 hours for torchieres).

CFL Wattage Chart

CFL Wattage Chart

Frequently asked questions about CFL and LED bulbs

What is a CFL bulb?

A compact fluorescent light (CFL) is an energy-efficient light source. This technology:

  1. Saves energy: CFLs use 75 percent less energy than traditional incandescent lighting.
  2. Saves money: By replacing five most frequently used lights, like your porch light, CFL bulbs will help you save up to $60 each year in energy costs.
  3. Lasts longer: CFL bulbs can last up to ten times longer than traditional incandescent bulbs, almost 10,000 hours.

Puget Sound Energy recommends ENERGY STAR qualified products.

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ENERGY STAR qualified lighting products meet strict energy-efficiency guidelines set by the U.S. Environmental Protection Agency and U.S. Department of Energy, including quality and reliability of the products. The ENERGY STAR program monitors all CFL bulb early failures, so if an ENERGY STAR qualified product fails unexpectedly, e-mail and include the manufacturer’s product model number.

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Why should people use CFL bulbs?

Switching from traditional incandescent light bulbs to CFL bulbs is an effective, accessible change you can make right now to reduce energy use at home and prevent greenhouse gas emissions that contribute to global climate change. Lighting accounts for close to 20 percent of the average home’s electric bill. Changing to CFL bulbs costs little upfront and provides a quick return on investment.

If every home in America replaced just one incandescent light bulb with an ENERGY STAR qualified CFL bulb, it would save enough energy to light more than three million homes and prevent greenhouse gas emissions equivalent to those of more than 800,000 cars annually.

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What is color temperature?

Color temperature describes the appearance of the light in degrees Kelvin. Qualified CFL bulbs labeled “warm white” or “soft white” produce a color of light like warm incandescent light bulbs. These types of CFL bulbs are identified by a color temperature of 2700 K. CFL bulbs that have a cooler color (similar to bright-white incandescent bulbs) are usually labeled “bright white” or “daylight” on the product packaging and are identified by a color temperature of 3500-6500 K.

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What is a watt? What is a lumen?

A watt is the measure of power consumption, and is the common way incandescent light bulbs are identified—for example 60-watt, 75-watt and 100-watt. When purchasing a light bulb, what you really should look for is lumens, which is the measure of light output. A 60-watt incandescent bulb produces about 800 lumens. A 13-watt CFL bulb will also produce 800 lumens, and it requires much less power.

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Can I turn my CFL bulbs on and off frequently?

To take full advantage of the energy savings and long life of ENERGY STAR CFL bulb, use them in light fixtures you use frequently and are on for at least 15 minutes at a time. Good locations include outdoor light fixtures and indoor light fixtures in the living room, family room, kitchen, bathroom, and bedroom.

It is a good habit to turn the lights off when you leave a room for an extended period of time. You may have heard that CFL bulbs use a lot of energy when turned on and off. While there is a brief surge in energy use when a CFL bulb is turned on, with today's starting technology, that surge usually lasts about a tenth of a second. So, even when turned on and off frequently, a CFL bulb uses less energy than its incandescent equivalent.

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Can I use a CFL bulb with an electronic control such as an electronic timer, photo sensor, motion sensors, dimmer switches or three-way?

Most electronic controls are designed to work with the simple technology of an incandescent bulb rather than the complex circuitry of CFL lighting. Some electronic timers, motion sensors, and photocells contain parts that are incompatible with CFL bulbs, thus resulting in a shorter light bulb life. It is possible for electronic controls to be designed to work with fluorescent technology, so check with the manufacturer of the electronic control device for compatibility.

Note that CFL bulbs can be used with mechanical timers (those that do not use electricity to operate) without adversely affecting the performance.

To use a CFL bulb on a dimmer switch or three-way—you must buy a bulb that's specifically made to work in these special applications. Check the package, as specialty bulbs are labeled well indicating if the bulb is suited for a special application.

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Can I use my CFL bulb in a totally enclosed fixture?

Before purchasing a CFL bulb for a totally enclosed fixture, you should check the product packaging. CFL bulbs that are not designed for totally enclosed fixtures will typically carry a disclaimer that indicates that they are not intended for this type of application. Because totally enclosed fixtures do not allow air to circulate around the lamp, it causes heat to build up, which can lead to performance issues.

Though CFL bulbs do not produce nearly as much heat as incandescent ones, they are more sensitive to heat, which can affect their performance. Some of the components in a CFL bulb can not withstand high heat, unless specifically engineered to do so. The excess heat that is created in a totally enclosed fixture can cause the light output to be diminished, the bulb to appear to "dim" more quickly than CFL bulbs used in applications that allow airflow, and a shorter bulb lifetime. The most effective way to ensure that a product you are interested in purchasing is designed to withstand high-heat applications, is to check the packaging for a specific labeling or qualification that the CFL bulb is designed to withstand high-heat applications or recommended to use in enclosed light fixtures.

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Can I use a CFL bulb in applications involving vibrations like ceiling fans or garage door openers?

Vibration can cause the electronics in the CFL bulb to fail. Currently, it is not recommended to use CFL bulbs in vibrating environments, however, ENERGY STAR qualified ceiling fans are engineered to accommodate this performance issue. To save energy and money with your ceiling fan, look into purchasing an ENERGY STAR qualified ceiling fan fixture.

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Why else might my CFL bulb be burning out early?

  • Bad light fixture wiring: Light fixtures wear out over time and develop wiring problems that can shorten the bulbs life. If your fixture continues to burn out with different brands/packages of CFL bulbs, then this may be the problem.
  • Wattage was too high: Read the package, use the appropriate wattage within the light fixture capacity.
  • Faulty bulb: Millions are made, a few might be faulty. ENERGY STAR qualified CFL bulbs have a warranty of 2 years. Keep your receipt and return to the original retail store to get a replacement.

If you purchased a CFL bulb from a retail store and you did not keep the receipt, call the toll free number provided by the manufacturer on the packaging and have the early failure CFL bulb at hand—they may need the numbers imprinted on the base. Each manufacturer has different warranty rules and expiration times. Expiration times range from 1 to 7 years and depend on the type of CFL bulb and when it was actually manufactured (not when it was bought from the retail store).

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What are LEDs? How do they work?

LED stands for light-emitting diode. LEDs are small light sources that become illuminated by the movement of electrons through a semiconductor material.

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Are there ENERGY STAR qualified LED replacement screw-in bulbs?

Yes—visit the list of qualified LED replacement screw-in bulbs. This ENERGY STAR product category does not include the long tubes often seen in office buildings.

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Are LED lighting products dimmable?

Yes, LED lighting products can be dimmed, but not all are. LED bulbs and fixtures must be designed to dim, and they are not compatible with all dimmer controls designed for incandescent bulbs. It may be necessary to replace existing dimmer switches with ones that are compatible with the LED lighting product. Check the packaging or accompanying instructions to find out if the product is dimmable and which dimmer products are approved for use with the product. As the LED industry grows, fully compatible LED dimmers will become more prevalent in new construction. In the meantime, confirm with the manufacturer that their product is compatible with your dimmer.

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Do LEDs create heat?

LEDs don't feel hot to the touch. like other light sources. Incandescent bulbs produce heat that is felt in the beam of light, much like the heat that is felt from sunlight. The light from LEDs does not create additional heat in a room. Nevertheless, LEDs do create some heat that can affect the light quantity and quality over time. To combat the negative effects of heat on LED performance, manufacturers incorporate heat sinks in their designs to transfer heat from the LED. Like a cold spoon that warms up in a hot cup of water, the heat leaves the LED through the heat sink, in a process called conduction, without emitting heat. The metallic fin-like features commonly found on LED bulbs and fixtures are heat sinks.

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What color of light does ENERGY STAR qualified LED lighting come in?

ENERGY STAR qualified LED lighting is available in a wide variety of shades of white light, "warm" light comparable to the yellowish light of incandescent bulbs, "bright white" light for reading or bluer "cool" daylight for task work. Light color is measured on a temperature scale referred to as Kelvin (K). Lower Kelvin numbers mean the light appears yellow; higher Kelvin numbers mean the light is whiter or bluer. Color for ENERGY STAR qualified LED lighting for indoor residential use is restricted to 3500K or less to provide only warm white light, with the exception of portable desk bulbs that can be as high as 5000K where the light just starts to appear more blue.

  • To match the color of incandescent bulbs look for 2700-3000K
  • For a whiter light, look for 3500-4100K
  • For bluer white light, look for 5000-6500K

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What is a watt? What is a lumen?

A watt is the measure of power consumption and is the common way incandescent light bulbs are identified—for example 60-watt, 75-watt and 100-watt. When purchasing a light bulb, however, what you really should look for is lumens, which is the measure of light output. For example, when you purchase a 60-watt incandescent bulb, you are getting about 800 lumens. By selecting a 13-watt ENERGY STAR qualified CFL bulb instead, you can still get 800 lumens, but it requires much less power.


For more information on LED lighting go to

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