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Shop lights

When the Crave brothers of Waterloo, Wisconsin, built their shop in 2008, their options for shop lighting seemed endless. The one thing the four brothers knew was that they wanted lighting that was energy efficient. “Our biggest goal was to limit electrical use,” says Tom Crave.

According to Greg Brenneman, Iowa State University ag engineering specialist, the Craves were halfway there when it came to what they needed to know as they looked at lighting.

“Farmers should consider two general questions,” Brenneman says. “First, how much lighting is needed for the task? General office and shop work may only require about 50 foot-candles, but detailed benchwork or specific office deskwork may require 100 foot-candles. General machinery storage only requires 3 to 5 foot-candles of illumination.”

The second question is how much light are you getting for the electricity used? “Significant energy savings are possible when using some of the newer fluorescent or high-intensity discharge lamps in areas where lighting is frequently used,” Brenneman notes.

Bulb of preference

For years, the preferred choices for lighting a farm shop were high-intensity discharge (HID) lights, such as metal halides or high-pressure sodium lamps, and T12 fluorescents. Each has its pros and cons.

Metal halides are available in a pulse-start or standard version. Typically, pulse-start is more efficient and has 50% more lamp life than the standard version.

High-pressure sodium vapors are more efficient than metal halides. They also work well in cold weather and are usually used for outside lighting.

HID fixtures produce intense light in small areas, which may be seen as a negative. They require a few minutes to warm up to reach their full light output.

Fluorescent lamps, on the other hand, emit diffused light, which has made them a popular choice for spaces with ceilings less than 15 feet high.

As lighting technology has advanced, a more intense and efficient fluorescent lamp, coupled with specially designed reflecting fixtures, has allowed fluorescents to break through ceiling-height barriers and become a direct competitor with HID lamps.

“As the T5s and T8s have gotten better, they've become more popular,” says Eric Howlett, vice president of Midwest Electric L.L.C., Johnson Creek, Wisconsin.


Types of Lighting

Cold Cathode Fluorescent Lights (CCFL)

These lights last two to three times longer than compact fluorescent lights (CFL), will start at lower temperatures, are compatible with many types of dimmers, and can be turned on and off frequently without significantly shortening bulb life. However, they are more expensive and are a bit less energy-efficient than CFLs.

Compact Fluorescent Lights (CFL)

CFLs can replace incandescent bulbs, as they don't require any wiring changes. Typically, they use 75% less energy than incandescents and can last 10 times longer. However, they won't operate below 0°, and they reach full light output after about a minute. Best suited in areas where lights stay on for extended periods of time.

High-Intensity Discharge

Includes metal halide and high-pressure sodium vapor lamps. Typically, they are easy to install and are good for ceilings higher than 12 feet. However, they need a few minutes to warm up before they reach full light output, and they are not a good choice if lights will be turned on and off frequently.

Light Emitting Diodes (LED)

Light emitting diodes (LED) are up to five times more efficient than incandescent lighting and last longer, with ratings up to 100,000 hours. LEDs provide directional light rather than 360° illumination other bulbs offer. They don't perform well in moisture, heat, and dusty environments.

Tube Fluorescent

Available in three diameters. T5 and T8 bulbs are 0.6 inch and 1 inch in diameter. T12 was the most common but is being phased out because it is the least efficient in this category. Most are suited for areas where they will be mounted less than 12 feet above the floor. Newer versions can handle higher heights.

Final answer: T5

To help narrow down the choices, the Crave brothers turned to Howlett for guidance.

“We made sure we installed the best product on the market at the time for what the Craves were wanting,” says Howlett. “And that was the T5.”

“Based on Eric's recommendation, we chose to go with six-bulb T5 lights,” says Crave. “They were very efficient and provided great working light.”

Today's T5 offers myriad advantages.

● More Energy-Efficient. A four-lamp T5 fixture draws 235 watts compared to 455 watts for a single-lamp metal halide fixture.

● Improved Light Output. A T5 has excellent light output. In most cases, the level of light output equals or exceeds existing metal halide output levels.

● Instant Start-Up. A T5 starts and restarts instantly. An HID fixture typically takes 10 to 15 minutes.

● Cooler. Compared to metal halide, a T5 is considerably cooler. A metal halide can significantly increase temperature levels in hotter months.

● Quieter. Because a T5 has electronic ballasts, it is much quieter.

● Longer Lamp Life. A T5 lamp maintains its light output over time. A metal halide and a high-pressure sodium lamp, on the other hand, lose between 30% to 40% of light output over the life of the lamp.

A T5 delivers higher lumens-per-watt (best way to compare lighting efficiency for similar size lamps) efficiency than a T8 around the same wattage. Because a T5′s peak light output happens at 95°F. (compared to 77°F. for T8s), it's ideal for hot locations. A T5 lasts about 20,000 hours compared to 15,000 for a T8 lamp.

No matter which option you consider, seek the expertise of an electrician.

“If you're working with an electrician, you know that person has the resources you need to put in the correct type of fixtures for the application,” says Howlett.

An electrician also has knowledge about rebates that can impact cost.

“For the Crave brothers' project, we worked with Wisconsin's Focus on Energy program, and we were able to get rebates back,” says Howlett. “At the time, they were $60 per fixture. That can add up to a lot of savings in a hurry.”

Incandescent Phaseout

As the phaseout of incandescent bulbs begins in 2012, farmers must look at alternatives to light their farm buildings. The first to go will be 100W bulbs, with 75W following in 2013, and 60W and 40W going in 2014.

A number of options take their place including energy-efficient technology like compact fluorescent bulbs, light-emitting diodes, and tube fluorescent fixtures.

To help sort through what's available, Iowa State University Extension has published, “Energy Fundamentals for Farm Lighting” (PM 2089N) and “Indoor Lighting for Livestock, Poultry and Farm Shop Facilities” (PM 2089R). They compare indoor and outdoor lights, spell out features, explain lighting terminology, and compare the energy efficiency of different bulbs. Find the publications at

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