Dimming Down Colorado Springs CO

While energy-efficient light bulbs do make a difference, in most circumstances that is not enough. To make those light bulbs as energy-efficient as possible, the right ballast technology is necessary. They go hand in hand like Abbott and Costello, Lucy and Ethel, Johnny and Ed.

Dimming ballasts is one such technology that is proving to be a good partner in the lighting world, particularly fluorescent lighting. "Dimmable ballasts enable the opportunity to vary the amount of light from a fluorescent light fixture," says Stuart Berjansky, senior product manager, Dimming and Controls Advance, a division of Philips Lighting.

Berjansky explains that in general, upon receiving a dimming signal, the ballast will vary the amount of current to the lamp cathodes. As the current decreases, the amount of light decreases. He points out that dimming ballasts enable three primary and beneficial outcomes. They are:

• Energy savings: When used in conjunction with occupancy sensors, daylight sensors and/or building management systems, fluorescent fixtures incorporating dimming ballasts have the ability to reduce the amount of energy utilized within a facility.
• Scene setting: Scene setting controls allow fluorescent fixtures to be dimmed in response to a required atmosphere and can be used to enhance a variety of spaces, including conference rooms, classrooms and hospitality settings.
• Personal control: Personal control allows a space occupant to modify the light level based on a comfort level they deem appropriate for the task at hand.

Ballast types

Ballasts can be broken down into three basic categories, Berjansky says. They are fixed output, step dimming and continuous dimming. Fixed-output ballasts allow for on/off control of a light fixture, Berjansky explains. Step-dimming technology provides light variation based on pre-defined settings, or steps.

"Depending on the ballast design, steps can be designated from options as simple as high/low to a greater degree in many increments," Berjansky notes.

Continuous dimming capability provides the opportunity to set light output at any point along the ballast's output range. "Continuous dimming ballast will provide for the greatest amount of energy savings while still keeping lights on," he adds.

One company, PureSpectrum Technology, has been developing and testing ballast technology that creates what they call a "true dimmable compact fluorescent bulb." The company claims it has developed an electronic ballast circuitry design that enables CFL products to be fully dimmable by using a standard dimming device.

"This technology addresses a serious issue consumers have had with CFL bulbs," says Lee Vanatta, president and CEO, PureSpectrum.

The circuitry design allows a CFL bulb to be dimmed to below 10 percent of perceived light output with a standard dimming switch, and it allows a CFL to function side-by-side with incandescent bulbs and mimic performance characteristics such as low light starts. PureSpectrum says its ballast circuitry improves energy efficiency for linear fluorescent lamps and enhances multiple performance areas for CFL bulbs. The company adds that independent testing from Intertek shows sizable gains in both start time and run-up delay time, while maintaining comparable energy efficiency.

Furthermore, PureSpectrum claims its ballast model has a component count similar to a standard non-dimmable CFL bulb and features a high power factor built into the ballast. "Our ballast uses a different circuit topology that will allow a CFL to dim just like a standard incandescent," says Ray King, director of engineering, PureSpectrum.

"The dimming technology takes the light down in a gradient, incandescent-type performance," Vanatta adds. "Incandescent set the standard for what people are used to, and dimmable ballasts perform to those incandescent standards."

Bright future

And the future looks bright for dimming ballasts. Berjansky says they represent an optimal means of achieving greater control of the environment by space occupants. And not only does the technology allow for better control of one's local space, it also provides benefits to the overall environment.

"Dimming and controllable ballasts also will play an increasing role in demand response and utility-directed energy management as energy conservation and sustainability become key drivers in commercial and industrial lighting applications," Berjansky says.

He adds that dimmable ballasts can contribute significantly to national and global goals of minimizing greenhouse gas emissions as well as reducing energy consumption and costs.

Vanatta adds that dimmable ballasts often have fewer components, which helps to drive down the costs and makes them more affordable. He notes that they also are a more efficient transmission of electrical power and create less heat buildup.

"The dimmable ballast technology exceeds the requirement of Energy Star. Everything is changing and will continue to change," Vandatta explains. "We have to think about lighting and energy. Until recently, we didn't have to think about it."

Overall, ballasts play a lead role in obtaining greater lighting efficiency. The ballast is one of three primary components that drive lighting efficiency, notes Doug Stoneman, manager, Channel Marketing, Advance. (The other two are the lamp and fixture.)

"The ballast is the 'engine' of the light delivery system, thus playing a critical role," Stoneman explains.

He says there are two ways a ballast drive efficiency. One is the ballast itself can be designed to be more efficient. The second is the ballast can operate the lamps more efficiently, primarily by operating them at high frequency.

"The development of ballasts that drive greater efficiency is a high-tech process that involves all aspects of design, from board layout to component selection," Stoneman says.

In general terms, the ballast can deliver 6 percent to 10 percent improvements in efficiency over standard electronic ballasts. In combination with new energy-saving T8 lamps, for instance, standard electronic ballasts can help lower system energy consumption by at least 40 percent.

According to the U.S. Department of Energy, lighting accounts for about 22 percent of the total electricity generated in the United States. It is said that just one CFL bulb during the course of its life can save a consumer between $40 and $50 in utility costs. That same CFL bulb is said to save 630 pounds of coal from being burned or 51 gallons of oil. It will also prevent 1,072 pounds of CO₂, 7.8 pounds of acid rain and 4.1 pounds of smog from going into the atmosphere. Dimming ballasts can only add to those benefits.

"Dimming ballasts represent a lighting solution that delivers greater energy efficiency, environmental responsibility and sustainability, and one that will help us to drive a more energy-efficient future for generations to come," enthuses Berjansky.

Berjansky adds that as a result of these positive trends, industry sales of dimming ballasts continue to grow and he says they will continue to be the focus of extensive industry research and development efforts in order to meet the long-term future needs of the range of applications they can support.