Introduction
An effective way of creating more prime time hours of tennis play is to include lighting in plans for new courts or to light existing ones. Lighted outdoor courts can provide additional hours of play for working people who, because of limited daylight free time, have no other choice than to play at night. In some areas, daytime conditions (heat, glare, wind) can be uncomfortable, making play in the evening desirable.
There are several ways to illuminate tennis courts using various types and configurations of lighting systems. The purpose of this guideline is to set forth some of the factors that should be considered and some of the system components available to provide a lighting system to satisfy the requirements of a particular tennis facility.
2.0
Objectives of Proper Lighting
A.
To make it easy to see and follow a ball at the time it is tossed in the air by the server, and while it is repeatedly hit and projected at every path it follows as long as it is in play.
B.
To minimize the glare from the lighting equipment.
C.
To design a system that is economical to install, clean, maintain and operate.
Be sure to note that it is not necessary to produce illumination simulating daylight, since the quality of the light is more important.
3.0
Quality of Light
Quality of light is determined by a number of factors including uniformity of distribution, background colors and a non-glare light source.
Lighting levels should be as nearly uniform as possible within the entire playing space, including approximately 6' outside the sidelines and behind the base lines approximately 10' and/or within 10' of the back walls.
High Intensity Discharge (H.I.D.) fixtures are commonly used. Whatever the style of fixture employed, it is very important to avoid a source of high intensity concentrated in a small area visible to the player. An after-image of the light source in the player's eye causes him momentary blindness and he cannot see the ball during that time.
4.0
Quantity of Light
The quantity of light is important, but must be considered along with other factors. In general, 60-75 footcandles average maintained is minimum while at least 75-100 footcandles average maintained is recommended for most facilities and 125 footcandles average maintained is minimum for professional, international, national and collegiate facilities. Televised events normally require 125 maintained foot-candles, however, recent developments in camera equipment do not require this high of illumination. Television networks should be contacted to determine the required lighting levels and locations for the event in question.
Light meter readings should be taken from a point 36" above the court surface with the light sensitized cell facing upward. The reading should include a location 6' outside the alley line of the court, and 10' behind the baseline. The variance from the average to the minimum or the maximum should be no more than 25%, preferably as low as 15%.
A.
Maintained illumination is determined by applying a light loss factor (LLF) to the initial calculated or measured foot-candle illumination. LLF depends on lamp characteristics, luminaire design, voltage variations, atmospheric conditions, and dirt accumulation. It can vary from 0.6 to 0.8. Consult manufacturer’s publications for proper LLF values.
B.
Average maintained horizontal and minimum maintained horizontal illumination should be the calculated or measured and the values multiplied by the appropriate LLF.
C.
Uniformity ratio is defined as the ratio of maximum illumination divided by the minimum illumination.
D.
Primary Playing Area (PPA) is defined as an area measuring 48’ by 98’ or 6’ outside the sidelines and 10’ beyond the baselines.
5.0
Location of Fixtures
Lighting fixtures should be located outside playing lines, preferably parallel to the alley lines and outside the fence. On fast dry courts, location and selection of fixtures is particularly important since rain dripping off fixtures can damage the fast dry surface. Fixtures should be aimed to project light across the court to eliminate glare. When lighting a multiple court facility, no light poles should be placed between courts except at the net line unless there is at least 24’ (7.315m) between courts. Any free standing lighting fixtures located inside the fence and more than 1’ (305mm) from the fence should be heavily padded to reduce player injuries. Since players often stand at or behind the baseline during play, at least one fixture per side behind the baseline is recommended. Special caution should be exercised, however, to insure that fixtures are placed in such a way that players do not have to look directly toward a light behind the opposite baseline when serving or during normal play. For this reason, no lighting fixtures should be placed at the back of the court behind the principal playing area and lighting fixtures located at the corners should be on poles no less that 35’ (10.668m) high and should be carefully aimed.
6.0
Fixture Mounting
New designs in HID sharp cut-off luminaires have reduced the required mounting heights to approximately 20’ with good uniformity, low glare, reduced amounts of spill light onto the surrounding area, and easier maintenance than on higher poles. For floodlight type fixtures, 35’ to 40’ poles are frequently used.
All poles should be designed to withstand wind velocities as required by local codes. Mountain and coastal areas will typically require higher strength poles because of higher wind conditions. Unless specifically designed as such, light poles should not be used to support the tennis court fence in addition to the light fixtures. Attaching the fence to the light pole adds additional loading to the pole, which could cause it to fail, and electrical codes may prohibit it.
Spill light, or light pollution, has become a major issue in regard to tennis court lighting. Some tennis court lighting locations, generally those located close to residential areas, require special consideration in regard to the amount of impact the lighting system has on the surrounding area. Low profile, sharp cutoff luminaires will generally have the least amount of impact in these locations, due to the low mounting height, reduced glare, and light control characteristics of this type of system. Lighting manufacturers can provide computer generated printouts showing the amount of light that will be projected outside of the court area.
7.0
Wiring
Underground wiring is recommended for tennis court lighting, using direct burial cables or conductors in conduit. In general, the supply voltage selected should be the highest available. This usually results in 277/480 volt, three phase systems for large facilities, and 120/208 volt, single phase systems for smaller applications. Voltage drop can significantly affect the lumen output of the lamp. Conductors should be sized to limit the voltage drop to 5% or less from the source of the luminaire. All wiring must comply with the National Electrical Code and applicable local electrical and building codes. Consult these codes or a local electrical engineer for wire requirements and wire sizes.
Fluorescent, mercury, and high pressure sodium lighting are stroboscopic (flickering) in nature. This can be eliminated by using three phase wiring, with each alternate fixture on a different phase.
When cost considerations prevent the initial purchase of a lighting system, consider electrical capacity and the placement of conduit for future expansion at a slight increase in cost.
8.0
Control Devices
Many types of control devices are available for tennis court lighting. A time clock device in conjunction with a photocell provides a good basic control system. Centralized switching, remote, or courtside time meters, and coin, token, or ID operated devices are available for different light sources. These options may be investigated for more convenient and efficient control to satisfy project requirements.
9.0
Costs
Maintenance, operating, and initial costs should be considered. Initial costs include fixtures, poles, wiring, installation and control equipment. Operating and maintenance costs include electrical operating expenses, lamp and lens replacement, fixture cleaning and labor costs associated therewith.
10.0
Maintenance
All luminaires should be periodically cleaned as recommended by the manufacturer to maintain maximum light output. As much as 30% of the light output can be lost over a period of time if the luminaires are not cleaned on a regular basis. Wipe lenses with a damp cloth since a dry cloth creates static electricity which causes dust to collect more rapidly. Louvres should be dipped in a cleaning solution, then in clear water. Both should be allowed to dry without wiping. Wear gloves when handling lamps since skin oils can reduce their efficiency and life.
Clean the fixtures at the same time relamping takes place. Relamping should occur at 75% of the rated life of the lamp. For economic reasons, it is recommended that all of the fixtures be relamped at the same time, rather than replacing one at a time. Consult luminaire manufacturer for maintenance instructions.
11.0
Special Note
Because of the numerous variables in designing a tennis court lighting system, it is recommended that an owner consult an engineer, architect or qualified tennis consultant or contractor who is completely familiar with tennis court lighting.
Section II.M.1 - Recommended Illumination for Outdoor Tennis Facilities
NOTES:
1. Maintained horizontal foot candles is determined by applying a light loss factor (LLF) to the initial calculated or measured foot candles. LLF is dependent upon lamp characteristics, fixture design, fixture maintenance, voltage variations and atmospheric conditions. It normally varies between .6 – .85. Consult the Illuminating Engineering Society Handbook and fixture manufacturer’s publications for proper LLF values.
2. Average maintained and minimum maintained horizontal foot candles should be calculated within the playing lines and/or within the Primary Playing Area (PPA) determined by the specifications of the project with foot candle values multiplied by the appropriate LLF.
3. Uniformity ratio is defined as the ratio of maximum foot candles divided by the minimum foot candles.
4. Primary Playing Area (PPA) is defined as the area that includes 6’ beyond the sidelines and 10’ behind the baseline.
Section II.M.1 - Light Meter Reading Location Diagram
Section II.M.1 - Typical Court Lighting Sections
Section II.M.1 - Typical Court Lighting - High Mast
NOTES:
1. Maintained horizontal foot candles is determined by applying a light loss factor (LLF) to the initial calculated or measured foot candles. LLF is dependent upon lamp characteristics, fixture design, fixture maintenance, voltage variations and atmospheric conditions. It normally varies between .6 – .85. Consult the Illuminating Engineering Society Handbook and fixture manufacturer’s publications for proper LLF values.
2. Average maintained and minimum maintained horizontal foot candles should be calculated within the playing lines and/or within the Primary Playing Area (PPA) determined by the specifications of the project with foot candle values multiplied by the appropriate LLF.
3. Uniformity ratio is defined as the ratio of maximum foot candles divided by the minimum foot candles.
4. Primary Playing Area (PPA) is defined as the area that includes 6’ beyond the sidelines and 10’ behind the baseline.
