How to Determine the Number of Fixtures Needed in a Parking Lot
Parking lots can be a large and difficult lighting project, especially for new builds. Safety and security is top priority for this type of lighting, and having a lot that is not adequately lit could lead to accidents or potential issues with crime and safety.
1:1 retrofit projects are simple enough, with just converting old metal halide parking lot fixtures to LED. But how does one determine the pole heights, pole spacing, or how many fixtures are needed for a new build? This parking lot lighting design guide will shed light on some general points to follow.
Footcandles and Light Uniformity
A footcandle is a measurement of illuminance for a square foot, where 1 footcandle is equal to 1 lumen per square foot.
In relation to parking lot lighting, these foot-candle ratings can go as low as 0.5 foot candles for a low-activity area of the lot, or as high as 5 foot candles in high-activity areas! It is generally recommended to have a minimum of 1 footcandle throughout the lot, with 2 to 4 parking lot footcandles of uniform light being within the ideal range for visibility.
Light uniformity also plays a large role in lighting a parking lot, as a higher uniformity means more even lighting throughout a lot, with an overall increased brightness and better visibility. A typical lot is recommended to have a uniformity of at least 3:1, meaning that the brightest point is no more than 3 times the footcandle rating of the darkest part of the lot. LED Parking Lot Fixtures generally have excellent light uniformity, and other factors such as pole spacing, number of fixtures on a pole, and landscaping may affect uniformity levels.
Pole Height and Number of Fixtures Per Pole
Parking lot pole heights can typically vary between 15-40ft high, and this height along with pole spacing and the number of fixtures on each pole will greatly affect the final result. Obstacles such as trees and buildings may require additional fixtures on each pole, or additional poles to be placed to ensure light uniformity. Local ordinances and city regulations might also require a certain maximum pole height allowance, but generally speaking the larger the lot is, the taller the poles will have to be.
Please note that each lot is different and may require a different type of layout in order to ensure optimized and even lighting throughout. A variety of Parking Lot Pole Mounting Accessories have been made in order to facilitate the use of additional fixtures on a single pole and maximize light uniformity and overall brightness in a parking lot.
Please feel free to reach out with any questions you may have regarding parking lot lighting design or any additional assistance you may need. For a photometric lighting layout based on your specific parking lot along with a complimentary quote using our LED Parking Lot Fixtures, please feel free to contact us at +1 (813) 649-8899 or at sales@htm-lighting.com!
- Michael Tomas