A, B, C’s of LED Sports Lighting Design: What’s Best To Know Before Purchasing? Following are simple A, B, C’s for a knowledgeable evaluation of a sports field lighting design before purchasing LED products from a manufacturer. With LED replacement or new lighting system installation so expensive, it’s critical owners and operators require each LED vendor to complete a sports lighting design before a purchase is made.
Whether a professional sports lighting venue or a small high school field, all sports field designs should incorporate the following minimum lighting design requirements (aka parameters; all obtained from IES (Illuminating Engineering Society) recommendations of specific sports venues; aka MLB, NFL, NCAA, Little League, respective state’s ‘High School League’, etc.
Following are basic lighting design parameters for sports fields irrespective of the size of the sports venue.
Average Foot-candle (FC) requirement is the first lighting design parameter, typicality established by the sports venue authority and sometimes reflective of the total number of stadium seats. An average horizontal FC requirement alone is used for high school or Little League with vertical FC additional requirements for a televised sports venue. An explanation of these FC differences. Horizontal FC’s are foot-candles measured looking aerially above a player’s head. Vertical FC’s are as measured along the player’s torso if standing upright. Since TV cameras are typically located at the sports playing field level, vertical FC’s are extremely important for such major events. To determine the IES foot-candle requirements for your respective sports, it’s a simple process of googling the authority as mentioned above. As example; googling SCHSL (SC High School League) lighting standards, page 5 of this document establishes horizontal 30FC’s or 50FC’s for football, lacrosse, soccer (depending upon number of spectators less than or more than 2,000), Baseball and Softball 50/30FC’s (infield, outfield), etc. Googling NCAA college football you’ll find various horizontal FC’s from lows of 50FC’s for sports play of less than 5,000 seats to 125FC’s for 46,000+ stadium seat National Championship Final Site Play football, 250FC’s for Broadcast basketball, etc. Additionally, vertical FC’s for a football field are a minimum of 125FC’s for 50 yard line cameras and 75FC’s end zone camera positions. As you might have guessed, many Division 1 colleges now desire an even higher FC, levels of professional sports play. Premier recently presented a 250FC design for the Philadelphia Eagles football upgrade, a same 250FC design for a Division 1 collegiate field upgrade requested before COVID hit.
Field Uniformity is another important lighting design parameter. As a simple definition, it’s a numerical ratio between the highest FC measurement and the lowest where the FC measurements are taken at a 3ft distance above the playing field surface inside 30ft by 30ft grid blocks across the field. If one were to obtain perfect lighting, this ratio would be 1.0 indicating all the FC measurements on the sports field are identical. You can probably visualize uniformity ratios as measurements of how equal (uniform) the lighting visually appears across the field. Hot spots on a field indicate poor uniformity ratios and much above perfect uniformity ratio of 1.0. A typical football high school field requires a uniformity ratio minimally (no worse than) 2.5 with the same 250FC collegiate field a 1.3 minimum uniformity ratio for aerial sports as baseball or softball and 1.5 for collegiate football. Premier designs high school football fields to minimum 1.5 uniformity; a lighting standard rarely ever offered by its competitors.
Uniformity Gradient refers to be rate of horizontal FC change across the sports playing surface. For high school fields, it’s the change in FC’s for every 10ft distance. Minimum uniformity gradient requirement for a high school football field lighting design is no more than a 10% change in horizontal FC’s every 10ft distance measurement across the field. Some lighting literature describes this as an abbreviation UG. This design parameter is much more important (and much less than a 10% change) for college and pro sports for HDTV broadcasting and for those sports with fast-moving balls because changes in light levels (illuminance) can make it more difficult to judge the speed of the ball.
CCT (Correlated Color Temperature), expressed as Kelvin Color, is also an important lighting design parameter designated by sports authorities. We have all heard the word ‘cool white’ when describing a fluorescent bulb. Cool white is a 4100 degree color on the Kelvin color scale of measurement. The lower the Kelvin color the warmer the color look (as one visually observes candlelight). Higher Kelvin colors are cooler or bluer in Kelvin color (like those new weird looking LED Christmas lights). Without detailed discussions, suffice it to say most high school sports are designed for 5000K (degree Kelvin), college sports 5700K and professional venues varying between lower and higher Kelvin colors.
Glare Index (GR for glare rating factor) is typically not a lighting design parameter for high school fields, mostly for college and professional venues. Glare is a subjective factor that measures the veiling illuminance produced by the light fixture and the ground point for an observer’s eye across every 30ft X 30ft or 10ft X 10ft measurement point on the playing field. Glare ratings are restricted to horizontal grids of points below eye level and used in outdoor area sports lighting applications. Glare rating ranges from 10 to 90 on what’s called the GR assessment scale. The lower the glare rating factor, the better the glare perception for the players in a sporting event. Minimum GR rating value of 50 is generally specified for collegiate and professional sports jobs. Premier LED products have shown to produce a lower Glare Rating across a sports field than our competitors in both collegiate and professional sports lighting designs. GR (glare rating) factors for a sports field are computed with our AGI32 lighting design software.
Total KW (total Kilowatt Demand) is an extremely important output calculated number that’s generated by every lighting design. It’s a simple mathematical addition of the total number of LED fixtures required to provide the desired sports lighting design multiplied by the individual fixture watts multiplied by 1,000. That is, it’s a calculation (as measured in KW) of the total electrical load required to light the sports field. The lower the total KW load of the lighting design, the lower total utility cost to operate the LED fixture system over its 50+ year expected lifetime. A lower total KW lighting design when compared to a competitor means the lighting system is more efficient and the system delivers more of the fixture’s lumen output to the playing surface and less wasted off the field into the neighborhood or into the environment. Again, Premier LED sports lighting systems offer the lowest total KW energy consumption as compared to its major LED sports lighting system competitors. Such annual energy savings add up quickly over the LED system life. Thus, a primary reason for comparing alternative LED manufacturers with a 25 year TCO (Total Cost of Ownership) calculation where the initial LED project cost is added to ‘25 years worth’ of utility (energy) costs.
In summary, call an experienced Premier staff member should you have any questions about a sports field design. A no obligation consultation and sports field upgrade or new ground-up quote will likely provide a better quality lighting system thousands of dollars of energy savings over the life of this investment. www.premiersportslighting.com