Traditionally our arenas have been illuminated by high intensity discharge (HID) fixtures. Metal halide technology is the most common of the HIDs utilized in arenas because of the clean white light it produces along with fairly good colour rendering ability (CRI of 65-70) and efficacy (65-100 lumens/watt). While metal halide technology ensures the goal of meeting horizontal illuminance levels to provide safe activity on the ice surface it does have many drawbacks.
We are all familiar with some of the limitations and constraints of metal halide technology.
- Significant Light Depreciation
- Average of 35% light depreciation occurs by 40% of rated life
- This significant light depreciation means we must design the lighting such that even when lamps reach their full light depreciation they still provide enough light to meet or exceed the lighting level recommendations whether it be IES (Illuminating Engineering Society) or ORFA recommendations
- Colour shift often occurs with time
When metal vapours within the lamp expire from heat and burning, the mixture of gases within the arc tube tend to result in a pinkish hue. This usually starts to become evident as early as 40% loss of original light output.
- Long warm up time
- Probe Start lamps take approximately 4-6 minutes to warm up on first start up
- Pulse Start lamps take approximately 2 minutes to warm up on first start up
In an effort to avoid the long warm up times lights are often left on for extended periods of time when area is vacant
- Long restrike time
- Probe Start lamps take approximately 10-12 minutes to restrike
- Pulse Start lamps take approximately 4 minutes to restrike
To ensure the safety of athletes and patrons, back up lighting in the form of linear fluorescent or halogen lighting are installed to provide safety lighting in case of power failure.
- Most systems don’t dim
- All or nothing lighting levels for all levels of play, activities and utilization
- Dimming ballasts are expensive
- Few facilities have invested in this technology due to cost
- Lamp life is relatively short
- Typically 15,000- 20,000 hours rated life ( Rated lamp life is the time it takes for one half of the test lamps to burnt out)
Lack of light Uniformity
- ‘Hotspots’ or ‘Banding’ created by the point source nature of metal halide lamps on an ice surface.
Moving Forward – Choices
So what technologies are available and what is the best choice for your facility?
With the many options and the large upfront costs associated with both retrofit and new construction this decision can be a little daunting. Sales people representing all different technologies and products will all claim “we have the best technology for you”.
So where do we start…….
A good place to start is to consider the following questions:
- How is your facility currently utilized and what is the highest level of play/competition?
2. How may your facility be utilized in the future?
3. Consider how important the following are to your goals of operating your facility:
|(Scale 0 to 5, 0 being not important, 5 extremely important)|
|Athlete Safety and Experience||0 1 2 3 4 5|
|Fan/Patron Comfort & Experience||0 1 2 3 4 5|
|Meeting Broadcasting/HD Broadcasting Criteria||0 1 2 3 4 5|
|Energy Savings/Reducing Energy Costs||0 1 2 3 4 5|
|Reducing Maintenance Costs||0 1 2 3 4 5|
|Reducing Life Cycle Costs||0 1 2 3 4 5|
|Being Environmentally Friendly/ Reducing Hazardous Waste||0 1 2 3 4 5|
The answers to these simple questions help identify the lighting requirements for your facility and help guide us towards which technologies can best meet these requirements.
Utilization of Facility – Present and Future
Once you have determined how your facility if utilized both now and in the near future you can then start to look at the specifications that the chosen lighting technology will have to meet in order to achieve the right outcome.
Lighting Levels (Illuminance)
When determining the lighting level requirements for the purpose of safety and enjoyment you must consider which activity has the most stringent requirements and ensure these are met.
In North America we use The Illuminating Engineering Society (IES) Best Practices for Sports and Recreational Area Lighting RP-6 -15 as best practices for recommended minimum illuminance levels. Recommended average maintained illuminance levels for sports activities take into account:
- Type of Sport – Aerial or Ground Level
- Class of play and facility – level of play, size of facility and # of spectators
- Horizontal Illuminance requirements
- Vertical Illuminance Requirements
- Uniformity Requirements
In 2013 ORFA published Public Skating: Guidelines & Best Practices. Below is the recommendations made by OFRA based on IES recommendations.
|Building Area/Activity||Foot Candles||Lux|
|Recreational Hockey (IES)||30||300|
|Recreational Skating (IES)||15||150|
Source: ORFA Public Skating: Guidelines & Best Practices Oct 2013
*The ORFA recognizes these as minimum lighting levels for recreational ice‐skating. A well‐lit ice surface will help to ensure that public safety is maintained thereby mitigating the risk for skater injury. ORFA recommends that facility management raise lighting levels for public skating to 30‐ footcandles/300 lux in keeping with the levels for recreational ice hockey.
We must consider Broadcasting/HD Broadcasting requirements if applicable. More and more sports events are being broadcast in high definition (HD). Recording in high definition requires specific illuminance levels, illuminance uniformity, colour temperatures (CCT), CCT uniformity, Colour Rendering (CRI) and the absence of flicker.
Illuminance and Uniformity
The National Collegiate Athletic Association together with ESPN have set out best practices for lighting requirements for broadcasting purposes.
Correlated Colour Temperature (CCT)
Correlated Colour temperature (CCT) of a light source is the temperature of an ideal black body radiator that when heated to a given temperature radiates a comparable hue to that of a light source 1. Colour temperature is typically expressed in Kelvin (K), with the light produced by incandescent sources in the lower temperature range of 2,700-3,000K and day light ranging from 5,600 – 10,000K. Many newer lighting technologies are available in a variety of colour temperatures to suit any application.
While the broadcasting industry typically colour corrects for light colour, it is advantages to approach what is typically considered by the photographic industry as daytime outdoor lighting (5,600K)2. It also proves advantageous for broadcasting to have colour temperature uniformity throughout the space. This allows televised colour presentation to appear as accurate as it does in person whether it’s at the goal line or at centre ice.
The Color Rendering Index (CRI) is a scale from 0 to 100 percent indicating how accurate a “given” light source is at rendering color when compared to a reference source3. The higher the CRI, the better the color rendering ability. In the past, only incandescent and halogen technologies could achieve the broad spectrum and colour accuracy similar to that of natural daylight (CRI 100). Today many fluorescent and LED lighting approaches or exceed CRIs of 90. Again, when it comes to broadcasting, the higher the CRI the more accurately colour is transferred to the television viewer.
While the average naked is not capable of detecting flicker > than 1500Hz, the HD camera is potentially much more demanding. Regular television broadcasting is typically shot at 25 frames per second (fps) while high definition is typically at 50-60 fps4. As camera technology evolves to allow for recording greater number of frames per second flicker free lighting becomes more important. While every lighting technology has products that have the potential to create obnoxious flicker, several LED companies have produced luminaires that remain flicker free even at frames rates greater than 2,500 fps. One Finnish company has even released an LED product that can achieve recordings of 100,000 fps flicker free5. That said, it is extremely rare to see recordings of greater than 1,000 fps in sport as the action speed itself does not require these rates to create compelling video coverage6.
Question 3 of our questionnaire addresses operational goals.
At the top of our list, the safety of athletes and patrons must always be a priority. We must ensure that light levels are such that whatever activity takes place in the facility it is done under safe conditions no matter which lighting technology is selected. When considering a lighting retrofit one should always carry out photometric design to help predict the new light levels and the uniformity of the light throughout the space. All lighting technologies have the ability achieve recommended light levels, however some may do it in a more efficient manner, by using less fixtures, less wattage and/or reduced life cycle cost.
When it comes to “experience” whether for the athlete or patron, lighting can make all the difference.
Colour Rendering Index (CRI)
As an athlete or fan we all want to view the activity in “true colour” as if the activity were taking place outside in daylight. When the sport involves speed, colour rendering become more important. Many athletes will contest that even in daylight conditions it is sometimes challenging when opposing jersey are close in colour. While we don’t require a CRI of 100 to observe and distinguish different shades of colour in sport we typically utilize a light source with a CRI of >70.
Glare & Spotting
Glare is a visual sensation caused by excessive and uncontrolled brightness. Glare within a sports venue can be both uncomfortable and potentially impeding to the activity. To reduce glare experienced by athletes and patrons, light source distribution and location needs to be addressed during the photometric design stage. It is not just the lighting technology type but it’s placement within a luminaire (fixture) and the optics such as reflectors, lens etc. which determine how light is distributed within a space. Every lighting technology has the potential to create uncomfortable glare. It is up to the lighting designer to ensure that luminaire location and the selected distribution pattern works within the space to minimize glare.
Spotting is created when there is contrast of light levels in adjacent space. Like glare, it is the goal of the lighting designer to minimize spotting (hot spots) by improving uniformity of light levels throughout the space.
Dimming can have a role in the experience of the space. Our arenas can often have more than 1 use. It is quite typical for facilities to utilize the ice pad areas in off season for concerts, trade shows, galas, parties etc. The ability to dim the lights for such events allows the lights to be adjusted for different events and applications. Not all technologies allow for dimming and some technologies such as LED may come standard with this ability.
Energy Saving/Reducing Energy Costs
Whether in the private or public sector, reducing energy use and costs is typically a goal of every facility. When it comes to arenas there are many ways to achieve energy savings.
Luminous efficacy is a measure of how well a light source produces visible light. It is the ratio of luminous flux to power and is expressed in lumens/watt. We can look at the efficacy of the lamp or in the case of LED the LED package, or we can look at the luminaire efficacy. In most cases these are two very different things.
When selecting a technology we must keep in mind that it is not just the efficacy of the light source but the efficiency at which the luminaire (housing) can direct the light to where it is required. For instance, a typical 100 W metal halide lamp (ED17 Shape) may produce 7,700 mean lumens but the visible light that escapes the source is in an omni-directional pattern. It is the role of the luminaire and the optic system to direct the light to the target.
One of the reasons LED technology has the ability to have greater luminaire efficacy is the uni- directional nature of the LED package. If the luminaire (housing) is designed to enable visible light to be emitted directly at the target then less watts are required to illuminate the same space. This is known as the light power density and is typically expressed in watts per square ft.
Control Light Source
Lighting controls allow lights to be turned off or dimmed when not required. Lighting controls may include occupancy sensors, timeclocks, photocells, dimmers and/or a fully integrated lighting control system. Each “control” option has its role in reducing energy use.
Occupancy sensors turn lights “OFF” when space is vacant and “ON” when movement is detected. Occupancy sensors can only be used with lighting sources that have instantaneous start.
Timeclocks or timers are pre-set to turn lights “ON” and “OFF” at a specified times of day.
Photocells turn lights “OFF” or dim light source when daylighting from windows or skylights is adequate for the space. Photocell thresholds can be specified or adjusted to ensure light levels meet recommended requirements.
Dimmers allows light fixtures to be dimmed to pre-set or manually adjusted levels specific to task. Example – A light source can be adjusted to full output (50fc) for Rep. Hockey games and decreases to 30 fc for public skating and house league practice times. A savings of 40% can be achieved for a large portion of the day. Please note not allow light sources have the ability to dim effectively.
Fully Integrated Lighting Control System
A fully integrated lighting control system is a networked system which makes use of all or many of the above stand-alone controls together. These system can have varying levels of control from the ability to control each individual fixture, banks of fixtures, zones or a full building. They can be wall mounted within the space or reside remotely on a networked system that can be accessed by networked computer or web enables devices.
Example: In an arena application a lighting control system could have the ability to set a time schedule for a week or month and set the light levels for each task within that schedule. If connected to occupancy sensors it could also turn lights “OFF” when ice pads are vacant.
|Day||Time||Scheduled Activity||Light Levels|
|Monday||6:50 – 8:00||Figure Skating Practice||30 fc|
|Monday||8:01 – 9:00||Atom Practice||30 fc|
|Monday||9:01 – 10:00||Empty Ice||5 fc|
|Monday||10:01 – 11:00||Empty Ice||5 fc|
|Monday||20:01 – 22:00||Rep Hockey||50 fc|
|Monday||22:01 – 23:00||Maintenance||30 fc|
Reducing Maintenance Costs
Each facility has its own costs associated with maintenance. One should always consider all the costs associated with servicing a luminaire (fixture), including all the parts, equipment and the labour required. In the case of ice pads, labour and lift equipment rentals greatly outweigh the material cost of the lamps and ballasts. If the lamps and ballasts have fairly short rated life spans then costs can add up quickly. One should also look at how actual maintenance is completed. Do lamps get changed out on regular scheduled group replacement schedule or do you replace on a one for one system when the lamps burns out. Whatever the maintenance pattern the actual true cost must be considered.
If maintenance costs are high, it is may make more sense to go to a technology that has a longer rated life.
Reducing Life Cycle Costs
Once you have determined the lighting needs for your facility then life cycle costing analysis is one of the best ways to differentiate which technology is best for you. Life cycle cost analysis is a tool to determine the most cost effective option among different alternatives to purchase, own, operate, maintain and dispose of an object or process7. This is always a very worthwhile process because often upfront costs can play very little role in the whole life cost of a product. Sometimes a steep upfront cost can lead to greatly reduced energy cost, maintenance costs and disposal costs.
Environmentally Friendly/ Reducing Hazardous Waste
Many lighting technologies utilize mercury (Hg) in vapour form to produce light. While mercury is not dangerous while contained within the lamp, the disposal/recycling of these products does require care. The US EPA classifies mercury as a hazardous waste and as such in Canada we must dispose/recycle these products as provincial and territorial legislation requires. In many cases this come with a cost attached.
Thus far we have summarized some of the things to consider when selecting a lighting technology for the arena application. As you may appreciate from this quick summary, there is great benefit to hiring a lighting professional.
A lighting professional can:
- Perform photometric design to ensure all lighting needs are met (illuminance, uniformity, glare reduction etc.)
- Utilize photometric design to maximize energy savings/reduce upfront costs
- Recommend energy saving controls
- Analyze Life Cycle Costs to compare products and technologies
- Help recommend quality products which meet what manufacturers claim on their specification sheets from install to end of life.
Figure 1 is a simple comparison of lighting technologies as they stand today. Caution should be taken in painting all products within a lighting technology with the same brush. Quality of each components within a luminaire (fixture), the luminaire design and manufacturing, as well as all the costs associated can vary greatly. This is especially true for the exploding LED market.
WARNING – Not all LEDs are created equal. An unbiased lighting professionals can help you select a quality product that will meet all your needs and keep performing as predicted.
1 NLPIP Lighting Answers Volume 8 Issue 1 Oct 2004 http://www.lrc.rpi.edu/programs/nlpip/lightinganswers/lightsources/whatisCCT.asp (2015,Aug)
2 Ben Vollmer, “Sports Broadcasting Under LED Lighting”, Esphesus White Paper 12/31/2014
3 NLPIP Lighting Answers Volume 8 Issue 1 Oct 2004 http://www.lrc.rpi.edu/programs/nlpip/lightinganswers/lightsources/whatisColorRenderingIndex.asp (2015,Aug)
4 Cory Janseen, “Frames Per Second (FPS)” http://www.techopedia.com/definition/7297/frames-per-second-fps (2015 August)
5 Easy LED Finland http://easyled.fi/en/ (2015, August)
6 Ben Vollmer, “Sports Broadcasting Under LED Lighting”, Esphesus White Paper 12/31/2014
7 Life-Cycle Cost Analysis, 14 July 2015 https://en.wikipedia.org/wiki/Life-cycle_cost_analysis (2015, August)