Feature Article - October 2005
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Shed Some Light

How to avoid making costly mistakes when it comes to sports field lighting

By Kyle Ryan

Different systems for different play

Sports-lighting systems are the complete antithesis of the one-size-fits-all approach. What works at one high-school baseball field may not at another, so each facility must first determine what its needs are based on the activity. As the level of competition increases, so do the lighting requirements.

"If it's something that's going to be used at the collegiate level, where you have television cameras and such, then you're going to need to talk about television requirements, etc.," says Shawn Good, lighting department manager for Brinjac Engineering. "If it's just, say, a recreational league or play at a local park or something, then the requirements are much, much less."

Light intensity is measured by foot candle (fc), the total intensity of light that falls upon one square foot of surface placed one foot away from a light source that measures one candle power (also called "lux" in the metric system). The Illuminating Engineering Society of North America (IENSA) has "recommended practices" for all lighting situations, including sports. IENSA breaks facilities down into four categories, which it mostly bases on the number of spectators. For example, here's how IENSA defines the categories, and how each one has different prescriptions for the same sport, baseball.

Class I: Competition in front of thousands of spectators. These are the types of facilities where television coverage may come into play, which, as Good mentioned, adds a whole additional set of requirements. For baseball, 100 to 150 fc

Class II: Facilities holding up to 5,000 spectators. For baseball, 70 to 100 fc

Class III: Competitive play with some spectators. For baseball, 30 to 50 fc

Class IV: Competitive/recreational play, without any spectators. For baseball, 20 to 30 fc

Once facility managers establish their class, lighting systems become easier to figure out. When it comes to the lamps, most sports lights use the metal halide variety, part of the high-intensity discharge (HID) family. Although they're a bit pricier and require a few minutes to warm up, they're bright and provide excellent coverage and color rendition. They also last a really long time.

"If you're talking about something like a minor-league baseball stadium or a collegiate level, usually you're going to replace those, I recommend, about every 5,000 hours to maintain light levels," Good says. "If you're talking, say, in a recreational league situation, many of those can last upward of 20,000 hours."

That means 833 days or roughly two and a third years of continuous use. Obviously, no one's running their lights all day every day, so lamps can last years before needing maintenance.

"You're talking pretty significant amount of life," Good says, "especially in a recreational league situation where, even if they're operated a couple hours a night, they're only on a couple hundred hours a year. They'll last essentially forever."

But they don't just burn out like a regular household bulb; metal halides fade over time, which may not be perceptible to facility managers who see them every day. They grow accustomed to the lights' slow changes, and before they know it, the lamps are burning at half of their initial strength. To avoid that, Good recommends establishing a regular time to replace all lamps. At a recreational center, that might be every 15,000 hours.