Commercial outdoor lighting application can be a tough task to do well. It requires knowledge of the architecture, the landscape elements as well as sensitivity to light trespass for surrounding neighbours. The challenge in any design is to synthesize the natural and artificial into a unified aesthetic theme that supports safe operation, mobility and functionality. Some objectives in commercial outdoor lighting is not to view the property from a whole new light, but in a new light that unifies multiple elements into a well balanced field of relationships consisting of complimentary points of view and frames of reference. When done correctly commercial outdoor lighting provides one of the best examples of light’s pervasive and unifying influence of thought, form and action.

In the last few years commercial outdoor lighting has undergone some drastic changes due the public’s increasing awareness and concerns to light pollution, energy consumption concerns, light trespass and glare. People are getting more educated in terms of correct outdoor lighting criteria. Many cities have set standards to prohibit poor quality lighting techniques. Technology is playing a greater role as well. We have computer software that aid in determining the correct lighting levels for each specific situation. There is a greater amount of research these days, we have institutions constantly studying the effects of quality lighting; the IESNA (Illuminated Engineering Association of North America) and the Lighting Research Centre to name a few. Our world is changing and the way we see it, be it day or night, is increasingly more important to determine the correct product for each individual application.

Some of the lighting techniques used in the past are not welcome as much in today’s market. Flood lighting needs to be particularly monitored in applications. This is the most common technique done poorly. There are general formulas put in place to ensure glare and light pollution is kept to a minimum. Flood lighting however can be a fabulous application when done correctly. Flood lighting is generally used in four types of lighting design; facade lighting, wall washing, sign lighting and area lighting.

Facade Lighting
Facade lighting is probably the most common use for Flood lights however there is a general rule to follow. It works well when applied with a 2:1 ratio. For instance if you are placing your flood lights at a set back of 20 feet you should place them apart by 40 feet. It’s important to keep in mind the distribution characteristics of the particular fixture, often it is better to select the premium lighting fixtures with better optics and precise distribution characteristics especially when you have a few of them. By upping the quality in performance it allows you to eliminate quantity and installation time.

Wall Washing
Wall washing is a relatively easy way to showcase the architecture, display the businesses that inhabit the building and also create an appealing sense to the persons passing by. It is imperative that we keep with architectural lines of the building when using this technique. For instance, if there are architectural columns, place the appropriate sized luminaire on each column. When we are wall washing a building it’s not important to highlight the entire face of the structure but rather use the shadows to create depth and character.

Sign Lighting
Sign lighting is very common technique for flood lights it’s a relatively simple formula to follow use a 1:1:1.5 recommendation. If you have a set back of 4 feet, you should aim the flood light 4 feet up the sign. If you require more than one fixture it is a good idea to place them 6 feet apart giving you your 1:1:1.5 formula.

Area Lighting
Area Lighting is the trickiest and the most poorly applied application for flood lighting. In every city across this country there are flood lights on a pole that glare directly in your eyes as you pass by. It is essential to choose a specific luminaire with excellent glare control and uniformity properties and not many manufactures produce one with such elements. It is best to stay away from using flood lighting for an area lighting application, there are much better solutions for that specific application.

The lighter shades indicate higher concentrations of light pollution in North America, Europe and Asia.

Area lighting is an essential asset to any Commercial outdoor lighting design. Area lighting provides vehicular safety, pedestrian security and circulation. It is very important to analyze the space before selecting a luminaire for the task. Due to the world‘s light pollution as seen in this photo from NASA (C Mayhew & R Simmon NASA/ GSFC) our environment plays a greater role these days. Gone are the days that we have 10fc on a parking surface with glare and light trespass visible from the property line. Nice even illumination is the prescription for today’s outdoor area lighting application. Night friendly lighting fixtures and shields play a role in good lighting design. It is also important to illuminate all parking spaces, bicycle racks and garbage areas.

General Illumination
For general illumination it is a good recommendation to minimize the light levels, have a maximum foot candle reading of 6 directly under the source with an average of 2. When you are in close proximity to residential areas, a maximum of 4 foot candles directly under the source with an average of 1 should be attained.

It is an industry misconception that the most cost effective lighting fixture suits the majority of commercial outdoor lighting design. Pay attention to all aspects of the jobbefore determining the solution and take the total cost of ownership into account.

Light Trespass
Light trespass is an urban sensitive issue as well, it is important to have 0.5 foot candles or less light spill from the property line. Along with good luminaires with excellent distribution patterns you may also consider a shield to prevent light trespass. This applies to the property line as well as any area being lit near a window of a building.

Now a common misconception in terms of large parking areas is that one pole and four luminaires is the correct path to take. In most cases you can achieve better illumination characteristics by using a single high performance post top luminaire in place of the four shoebox type fixtures. This will directly result in even distribution pattern, easier installation for the contractor, a reduction in wind load and reduce the size of the pole. By using a 1000 watt post top over 4 x 400 watt shoeboxes, you are saving over 700 watts per pole with the ballast factored in. In many cases by upgrading the quality of the luminaire you can reduce fixture and pole quantities and save on the expensive installation cost. It is an industry misconception that the most cost effective lighting fixture suits the majority of commercial outdoor lighting design. Pay attentions to all aspects of the job before determining the solution and take into account the total cost of ownership.

When is a building mounted luminaire layout the correct solution for an application is a common question asked. This is a method that tends to get over used. It is a cost effective way but when done improperly offers little area lighting and poor max/min illuminance ratio to the parking area. Putting wall packs on the side of the building at a 20 foot spacing is seen on a regular basis. Is it good lighting? Not for most applications. There is a time and a place for each technique in outdoor lighting. For instance if you have a strip mall with one row of parking, the site is set in close proximity to the street and residences; using a night friendly wall pack can be ideal. Your space is limited and your needs are simple. Illuminate the parking spaces and the side walk in front of the building. Choosing a wall pack with a good forward throw distribution does a nice job of this. Mount the fixture higher on the wall to mimic a pole. You can even wall mount an area light if you prefer. Keep in mind we are trying to light a property so take the lighting levels to the property line. Darkness is not inviting to customers. Wall mounted fixtures are always a nice addition for aesthetic purposes as well. Keep in line with the architecture and you can high light the features, pay attention to doorways, we always require light to move around best.

Now that we have spoken about lighting for the task we need to address the light source and energy concerns. It is proven that people function best under white light. Metal Halide is an ideal choice in our climate. Even though high pressure sodium (HPS) is a more efficient source (lumens per watt), it is not suitable for most locations and user needs. Area lighting is usually best suited with Metal Halide. With a white light you see more colour and contrast. You could have the same space lit with HPS and Metal Halide with the same lighting level but due to the eye sensitivity Metal Halide the human eye will perceive the whiter space be better lit. In white light you need less of it. On the other hand HPS does have a time and a place if you are wall washing or façade lighting a rough stone building, you get a beautiful result from using HPS. HPS can cast shadows and create a beautiful effect, but remember HPS used inappropriately can look just awful.

Energy consumption, light pollution, light trespan and glare are some of the issues that need to be taken into accountfor outdoor lighting applications.

When we are designing outdoor lighting plans it is important to include control. The most cost effective for energy concerns as well as maintenance is to have a time clock interconnected with a photo cell. There is also the High- Low to consider, an effective way to control HID. High-Low works great and has been around for years. There are other types of dimming controls for HID sources but they are new and very expensive. It is important to use current and proven technology in all applications. Is fluorescent suitable for our climate outdoor? It is coming but we are not there yet. Should low pressure sodium be used? I would advise against it, it is a thing of the past.

There are many tools to aid in outdoor lighting design to make a contractor’s job easier. Keep in mind that the major manufacturers have done extensive research on their product and they have a lot to offer when it comes to performance features and options for a wide range of lighting fixtures. These manufacturers can even aid in some lighting calculation and layout advice. There are excellent guidelines that have been created such as RP-33 from IESNA. There are several software programs to perform lighting calculation to take the guessing game out of the equation (GENESYS III, Visual and AGI 32 to name a few). A lot of the lighting reps have knowledge to aid in your design and help you find the answer you are looking. Use the tools that are out there for you and always remember; any engineer, designer or contractor is only as good as their last job.

By Janine Mighton