Frequently Asked Questions

Will the life of a fluorescent lamp be shortened if turned on and off frequently?

Switching fluorescent lamps on and off does reduce lamp life; it also reduces the operating time that the lamp is actually turned on. For instance, a standard T12 F40 fluorescent lamp operating continuously for 24 hours per day has a total lamp life of 38,000 hours. Since a year has 8,760 hours this lamp would burn out in about 4.3 years. On the other hand, the same lamp operating 12 continuous hours per day has a lamp life of 30,000 hours. Although the lamp life has been reduced by about 21%, the operating time of the lamp has been reduced by 50% and the “calendar life” of the lamp has been increased. Consequently, this lamp would now take about 6.8 years to burn out. In this case, both lamp replacement costs and energy costs have been substantially reduced.

How do fluorescent lights save energy?

A typical incandescent bulb creates light by passing an electric current through a wire to heat it until it glows. Therefore, ninety percent of the electricity used is wasted to generate heat, while only 10% of the electricity produces light. A fluorescent light uses electricity to generate a chemical reaction that produces light – up to 90% of the electricity consumed produces light.

Does it matter which fixture I use to replace a Metal Halide, High Pressure Sodium, or Mercury Vapor?

A number of factors must be considered when choosing the best fixture to replace a Metal Halide. Choosing the right optics is one of the most important. For example, a warehouse that is comprised of ten foot aisles and a large bay area for loading and unloading trucks; the aisles would require a fixture where the reflector used was designed to push the light straight down to the work plane in a more focused distribution. The lighting in the loading area would require a standard distribution. Other factors include: mounting height, wattage being replaced, desired foot candles, color of walls, ceilings and floor, and desired energy savings. Lighting software exists and is made available to lighting manufacturers to ensure the right fixture is used for the specific application.

How much money can I save by switching to efficient lighting?

The amount of savings is determined by a number of factors, including the original cost of the replacement lamps or fixtures, the electricity rates paid the number of hours the lights are left on and more. In almost every case, an efficient light will eventually pay for itself and go on to save you money. Investing in efficient lighting is practically guaranteed to give you significant returns.

Should my facility retrofit or replace our existing lighting fixtures?

The choice is typically driven by available capital. Both options will provide an immediate reduction is energy costs. Most retrofit projects replace the ballast and lamps. In almost all cases, a strip or troffer fixture can be retrofitted with a reflector and de-lamped as well. Retrofitting is an economical approach to quick returns and enhanced lighting.

Which is better: fluorescent or LED for a cooler/freezer door application?

Most retailers choose the LED product. LED cooler and freezer luminaires last up to 50,000 hours – add a sensor and the number of years between replacements are increased. LED strips are cooler to operate, which lessens the heat build-up within the case allowing the cooling systems to operate less than when used with standard fluorescents. The typical 5’ fluorescent lamp uses about 75 watts; the typical 5’ LED CooLED stick uses about 21 watts.

Why do utility companies offer rebates and where does the money come from?

The utility companies recognized a few years ago that it could be cheaper to encourage electricity conservation than to build additional power plants and distribution lines to handle our continually growing demand for electricity. The government agreed and allowed the utilities to charge every electricity user an additional fee for conservation. A portion of the money collected has been made available through use of rebate programs.

Can energy efficient lighting make a real difference for the environment?

  • Combined number of commercial buildings (4.8 million) and industrial facilities (350,000) in the United States: over five million
  • Combined annual energy costs for U.S. commercial buildings ($107.9 billion) and industrial facilities ($94.4 billion):$202.3 billion; Portion of energy in buildings used inefficiently or unnecessarily: 30%
  • Combined percentage of U.S. greenhouse gas emissions generated by commercial buildings (17%) and industrial facilities (28%): 45%
  • Percentage of energy use reduction targeted by the ENERGY STAR Challenge: 10%
  • Amount of money that would be saved if the energy efficiency of commercial and industrial buildings improved by 10%: $20 billion
  • Amount of greenhouse gas emissions that would be reduced if the energy efficiency of commercial and industrial buildings improved by 10%: equal to approximately 30 million vehicles. Number of registered automobiles in Illinois, New York, Ohio, and Texas combined: about 30 million

Source: (Department of Energy /

What is the impact of U.S. energy use on the planet?

  • The approximate energy released in the burning of a wood match: 1 Btu
  • Total energy used in the U.S. each year: 99.89 quadrillion Btu
  • Portion of U.S. annual energy use created by the combustion of fossil fuels: 86%
  • Amount of global carbon dioxide released into the atmosphere in 2005: 6,000 million metric tons
  • U.S. contribution of global Greenhouse gas emissions: approximately 20%; U.S. population represents 5% of the world population
  • Amount of greenhouse gas emissions that have increased between 1970 and 2004: 70%

Source: (Department of Energy /