Having lighting in a parking lot or outdoor area is very important. Not only does the make the location look nicer/more aesthetically pleasing, it also makes it safer. This could help your business thrive as thieves and troublemakers will stay away and customers will come in.
There are quite a few things to consider when deciding on a type of light to put in your outdoor space. Some of these things are the intensity of the light (how bright it is), the uniformity of it (how consistent the light is over the entire area), the color (how does the light render colors), the efficiency (how much light does it produce per watt used), and the lamp life (how long will it last).
There are many different types of lamps. Here are a few things you should know about them before you decide:
Mercury Vapor: Usually in locations built in the 60s or 70s. They glow with a blue-green light and have poor color rendition. While they have a great lamp life, it diminishes significantly and isn’t efficient (energy usage).
Low Pressure Sodium: They give off a orange-yellow light and have a poor color rendition and a fairly short lamp life. However, the vibrancy of the light fades slowly and these lamps are the most energy efficient.
High Pressure Sodium: These lamps were from the 80s or 90s. They also have poor color rendition, give off a yellow-amber glow, have a minimal light reduction, and are very energy efficient.
Metal Halide: These are near white lights with very good color rendition, a moderate lamp life, and have an energy efficiency that’s between poor and excellent.
There are certain lighting level standards decided by the Illuminating Engineering Society (IES). These can be achieved by using pole lighting. The poles are made of steel, aluminum, concrete, fiberglass, and even wood. While these used to hold high-density discharge (HID) and metal halide (MH) lamps, the smarter option now is to use LEDs. They are not only consume 50% less energy but also have good color and are durable.
Another option are flood lights. These can be used in pole lights or to accent landscaping. Again, it’s smart to use LEDs instead of the previous option—MHs. This way the lights will use less wattage and require minimal maintenance.
Now that you know your options, you’re probably wanting to make a decision. Before doing so it’s wise to measure the light levels on your location and have an awareness of what the standards for each of them are. Using a light-level meter, measure around the parking lot, marking each time on a map. The measurements will be in foot candles (fc), or if it’s metric, in lux.
Generally speaking, an outdoor area should be about .5 fc in a low activity area and about 5 in a high activity area where pedestrians may be. In parking lots, it’s advised to have a minimum light level of 1 fc but preferably 2 fc – 4 fc.
Another thing is the uniformity of the entire space. It is suggested to have a ratio of 3:1—3 being the foot candles of the brightest spots and 1 being the reading of the dimmest.
Keep in mind that there are some pretty unique situations with this as well. Some measurements may be as low as .3 fc and there’ve been some uniformity rations as high as 200:1! This is because it’s much brighter straight under a light (20-30 fc typically) and lower at the midpoint farther away from and between them (possibly .1 fc or lower). Landscaping also doesn’t help with this as it blocks the light and doesn’t keep it even.