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LED Lighting For The Outdoors and Building Exteriors

LED lighting is fast becoming the best solution for a wide variety of outdoor lighting applications. The reasons are simple: LEDs are the most energy efficient light on the market by far, they have the longest lifespan (and associated product warranties) by 2-10 times over the nearest competing technology, and they produce a very high quality light with a wide range of characteristics. They are small, steady-state lights which means they don’t present the breaking or recycling issues common with legacy lighting technology. Perhaps the only downside is that they’re not the cheapest light on the market. That said, the price continues to come down and a smart investor will recognize right away that a lifespan that could be an order of magnitude (10 times) longer than a traditional bulb is easily worth the investment. You get what you pay for after all.

Before After LED Parking Lot Lighting Retrofit From Stouch Lighting

One of the most important facilities for high quality outdoor lighting are outdoor parking lots. Parking lots present three major obstacles for owners, real estate organizations and facility managers. First, your parking lot needs to be well illuminated to present a welcoming and safe atmosphere for tenants and customers. The type and specifications of the lighting used in your parking lot typically sets the tone regarding safety and professionalism for the building at large. We refer to this general characteristic as lighting quality. Second, your parking lot lights need to be as energy efficient as possible because they typically operate from dusk to dawn. Third, maximizing luminaire lifespan is important because hiring labor and/or keeping staff on board to routinely change bulbs can become very costly. Primarily for these three reasons it is important to install the best combination of high efficiency, long lifespan, and high quality when choosing a lighting solution. LED lights are the 21st century answer to all three problems.

Lighting Quality:

The most noticeable difference between traditional parking lot lights like High Pressure Sodium and modern day LEDs is the color temperature. Notice the incredibly yellow tinge in the “Before” images to the left below. In the same yellow image take a look at the grass. The characteristic green color is almost indistinguishable. Compare that to the same parking lot when it is illuminated by LEDs. The first thing that stands out is all of the green. The trees and grass appear almost exactly like they do during the day. That is a much more welcoming and comforting experience for tenants, customers, and/or employees frequenting the lot.

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While the color of the new lighting is first thing you’re likely to notice in the image above, there are other less obvious improvements as well. Take a look at the image below.

Before After LED Retroft Neumann University Parking Lot Campus

The red boxes are highlighting lighting “dead areas” in the parking lot. Notice the difference in the foreground area in terms of shadow. The HPS lighting leaves a shadow (unilluminated area) in almost the entire area while the LED lighting distributes light nearly 360 degrees around the luminaire. Quick pitch: this result is not by accident. It is a direct result of the careful planning by lighting certified experts at Stouch Lighting who took into account both the particular LED light and it’s orientation in the parking lot.

 

Two major quality indices important to consider when choosing amongst LED lights are the color temperature and the color rendering index. You can read about them both here in more detail. In short, color temperature defines the glow and it ranges from a “warm” reddish orange to a very “cool” white to even bluish light. Color Rendering Index (CRI) more or less tells you how close the illuminated object appears relative to itself under daylight conditions. Color Temperature is more of a preference thing although some lighting technologies like LEDs are available in a much wider range. CRI is much more objective with values above 90 generally considered to be excellent. To better understand, consider the following image:

Before After Parking Lot LED Retrofit

The before section on the left has much more of a yellowish warm color temperature (roughly 2200K) while the after section with the LEDs on the right has a much cooler white color temperature (around 5500K). The color in the objects to the left (CRI around 50) do not render nearly as well as those to the right (CRI around 90).

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Ebook: 7 Different Lights LEDs Are Putting Out of Business

Energy Efficiency:

Operating luminaires for eight hours per night means running up energy expenses. Did you know? The cost of purchasing a building is only 10% of the total cost of operating it over its lifetime. The bulk of the operating costs come from energy consumption. Energy costs tend to fall into one of two major categories: HVAC and lighting. Outdoor lighting is a significant portion of the total lighting bill at most facilities. Perhaps the major exception to this trend is with hospitals and medical facilities that tend to consume more electricity inside the facility than other building types.

Reducing your expenses from outdoor lighting is all about driving down energy consumption in terms of useful watts on the ground per unit of energy consumed to generate them. Most recently (from roughly 1970 to the present) this problem has been solved by High Pressure Sodium (HPS) or Metal Halide lamps. Prior to that the luminaire of choice was a Mercury Vapor lamp. You can read about the history here if you are interested. In either case, lighting technology has advanced significantly since the 1970s. Today there is a huge wave of lighting conversions taking place where legacy HPS and metal halide lamps are being replaced with higher efficiency, longer lifespan, and better quality LEDs.

Take a minute to study the table below which shows a side-by-side comparison of the source and system efficiency of different lighting technologies. Source efficiency is less important than system efficiency because it takes into account light that doesn’t make it to the target area. Consider a bulb in an HPS parking lot fixture that emits light for 360 degrees. The light that is directed towards the sky must be reflected by the fixture back towards the ground. As you might imagine, there are losses inherent to this process. Not all of the light gets reflected. The energy burned to produce it is thereby lost. Because LEDs produce directional light (emitting for 180 degrees only vice the omnidirectional, 360 degree lighting produced by traditional lights) they are much more efficient at delivering light only to the areas where it is desired (the actual parking lot itself). Typical System Efficiency for an LED light is greater than 50 Lumens per Watt which is as good if not much better than any other light on the market.


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Lifespan:

Although quality and energy efficiency improvements with LEDs are impressive, perhaps the most significant generational leap involves the drastic increase in lifespan. LEDs literally last 2-10 times as long as the alternatives on the market. Not surprisingly, manufacturers are willing to guarantee their LED products for a much longer timespan (typically 5-10 years) where previously (with different bulb technologies) you would have been hard pressed to find a warranty longer than 1-2 years. With regard to common parking lot luminaires (metal halides and sodium vapor lamps), LEDs last 2-4 times as long. Imagine purchasing HPS lights for your parking lot and then having to repurchase them, hire labor, and replace the bulbs in your entire facility four times before ever having to do anything with your LEDs.

Type of Light

Lifespan

LED Light

25,000 to 100,000+ hours

Incandescent Light Bulb

1,200 hours

Halogen Light Bulb

2,500 hours

Mercury Vapor Light

24,000 hours

Fluorescent Light Bulb

7,000 to 15,000 hours

Metal Halide Bulbs

6,000 to 15,000 hours

High & Low Pressure Sodium Light

18,000 to 24,000 hours

High Intensity Discharge (HID) Light

6,000 to 24,000

Outdoor Lighting Fixtures (Parking Lots and Street Lights):

The last major consideration for professionally implementing lighting in both outdoor parking lots and along street lights and public areas is to determine the specifications for the lighting fixture itself. Most commonly used are pole-mounted lights but other options include decorative post tops and even building mounted fixtures for those areas in vicinity to structures.

Thinking about outdoor lighting? Here is a six-step specification checklist to make sure your lighting solution meets the minimum standards:

  • Compatibility: Ensure that the lamp or luminaire and the light will mount to the current/standard connections (or ensure that your supplier is taking into account the possible modifications or accessories needed to mount to the existing mounting application)
  • Corrosion Resistance: Make sure the fixtures have been sufficiently tested for outdoor and corrosive environments. Look for fixtures that have passed ASTM B117 salt fog or salt spray testing. In environments near the ocean (such as Florida for example) this is particularly relevant to prevent corrosion of metal or coated metal fixtures and early degradation of the light.
  • Electromagnetic Interference Standards: Ensure that the lights used meet Electromagnetic Interference (EMI) standards established by Title 47 Part 15 of the Code of Federal Regulations (47 CFR 15). 47 CFR 15 covers spurious or unlicensed low power emissions. Virtually all lights sold from retailers in the United States have been examined according to 47 CFR 15. Due diligence is more of an issue with lighting distributors using overseas manufacturers that do not typically retail products in the United States.

Rebate Options With LED Retrofits and Conversions:

If utility rebates are a priority, ensure that lights are listed on the Design Lights Consortium’s “Qualified Products List” or are Energy Stars certified. Read here for different options available.

Download The Ebook: Guide to LEDs For Real Estate Organizations

 

Parking Garage Lighting:

Parking garages are very similar to outdoor parking lots with one obvious difference, they have a ceiling. Luminaires are no longer mounted on a pole but otherwise the same major considerations for outdoor parking lot lighting apply. That is, patrons looking to retrofit or convert parking garage lighting are typically interested in reducing energy costs, reducing maintenance costs, and improving lighting performance. LEDs are still a wonderful solution for all of the same reasons previously mentioned. Two relevant concepts not previously discussed, however, include the use of adaptive lighting and the specification of light distribution patterns within a space to maximize the efficiency with which energy is consumed. Read more on these two money savers below.

Before After Photo LED Parking Garage Retrofit

Adaptive Lighting:

Another common consideration with parking garage lighting is to implement technology designed to adapt light levels to the variable occupancy rates within the different levels of the parking garage. As you might expect, many facilities experience higher traffic intensity near the entrance, exit, and on lower levels of the parking garage. Common sense generally applies and the law of least resistance dictates that the average patron will park in the closest and/or most convenient spot in the parking garage. It goes without saying that these areas will see higher intensity and/or more traffic than other areas in the garage that might only be used during peak hours. Although the particulars will vary depending on the situation, all lots will have their relatively higher use areas and their relatively low traffic areas. With that in mind, it makes a lot of sense to restrict and/or completely turn off lighting to those areas of the lot not being used. After all, why waste energy lighting up a room that nobody is using? It is a total waste of money. The solution is to retrofit key segments of the parking garage with sensors that track occupancy, traffic volume, and traffic direction. This is called “adaptive” lighting and it’s a Darwinian energy solution that has facility managers working smarter, not necessarily harder. Adaptive lighting involves the use of controls like motion-sensors or timers to deliver a pre-specified amount of lighting to different parts of the parking garage depending on the variable needs throughout the day and/or night. Sensors can be mounted on a particular or individual  fixture(s) or installed independently at specific locations as a means to control lighting output for a group of lights or an area/zone (e.g. a floor) within the facility. When the parking garage is experiencing high traffic volume and/or is fully occupied then higher light levels are likely to be used. Conversely, during low-traffic hours or when lower light levels are required, energy use can be drastically curtailed. Those parking garages, pathways, and/or building exterior areas with low occupancy rates and/or vacancy during a large portion of the night can save significantly on their energy costs through the use of adaptive lighting.

Light Distribution Pattern Analysis:

Upper Merion Township Parking Garage LED Lighting Conversion & Retrofit

A second and perhaps equally important aspect of energy efficiency inside a parking garage is to specify appropriate light distribution patterns within the space. This is done both by outlining the areas that really need lighting and also considering the amount of lighting desired in those regions. A lighting certified professional uses special equipment to quantify this information and will significantly simplify the process and will help you to choose and install the right lights for your particular situation. The two things you want to avoid are going overkill on your lighting and underachieving when it comes to desired quality. You want to strike a balance by achieving the desired light levels while not being wasteful with your energy resources.  

Lighting distribution is also a particularly interesting issue when it comes to LED lighting because of the way the technology works. LEDs are a semi-conductor and one of the significant technological advances with LED lighting in particular is the fact that emissions are directional (as opposed to omnidirectional). More specifically, LEDs naturally emit light for only 180 degrees while all other lighting puts out emissions for 360 degrees around the bulb. Consider a parking garage for a moment and recognize that a ceiling mounted bulb that emits light at 360 degrees is putting half of the energy consumed directly into the ceiling. Although some of this light can be reflected, much of it is wasted right off the bat. This is a significant contributor to the energy efficiency rates that can be achieved with LEDs relative to traditional bulbs. Add to this a prudent analysis where you specify the light levels and distribution patterns for your particular space and you’re well on your way to big savings. Top it off with a smart, adaptive lighting strategy that utilizes sensors to operate lights only in the areas they are needed, during the times they are required and at the desired intensity. Chances are good that your bottom line is going to noticeably improve - particularly for large facilities with significant energy footprints.

Street Lighting:

Color Temperature:

One major consideration for street lighting worth particular emphasis is the quality difference between LEDs and traditional solutions like high pressure sodium (HPS), low pressure sodium (LPS), and metal halide lamps. For example, the most noticeable difference between sodium vapor lamps and LEDs is the orange color associated with HPS/LPS lamps as compared to the higher color temperature white glow from LEDs. For a full discussion of this and other differences between LEDs and HPS/LPS lamps you can read here.

Neumann University Street Lighting Conversion HPS to LED Lights

Aston Township Street Lighting Conversion Sodium Vapor to LED Lights

Dimming:

A second major consideration for street lighting (particularly in residential areas) are the energy efficiency improvements that can be made through adaptive dimming. While dimming is available with most bulbs, there are significant advantages to LEDs as compared to traditional outdoor lighting solutions like metal halide and High Pressure Sodium (Note: HPS lights are the most common type of street light lamp). Additionally, it is very rare to see traditional HID lighting with the option to dim at all.

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The advantage to dimming lights is that you reduce the energy demand and increase flexibility for spaces with variable lighting requirements. This is generally true no matter which type of lighting you use. That said, how much improvement varies significantly depending on the particular lighting technology under question. Consider the difference between LEDs and metal halide lights. According to the Rensselaer Polytechnic Institute, “When HID lamps are dimmed, the reduction in light output is greater than the reduction in system input power. Thus, the efficacy decreases as the lamp is dimmed.” That is, metal halide lights consume more energy per unit of light output the lower power they are operated at. This is very much like driving your vehicle in a city versus the highway. Cars are more efficient per mile on the highway than they are in stop-and-go traffic. That said, this characteristic is very different with LEDs. According to the U.S. Department of Energy, “LED dimming performance is determined by driver capability and compatibility with the dimming equipment.” They go on to explain that LEDs are non-linear lighting devices when it comes to current which means that a small change in voltage can result in a large current change. They typically rely on maintaining an average and constant current level which in many cases tends to increase luminous efficacy as the current drops. This translates essentially to say “LEDs get more efficient [not less like metal halide HID bulbs] as they are dimmed.” You can read the DOE presentation here.

Further advantages include the fact that current LED lights do not shift color when they are dimmed. This is different than traditional bulbs like incandescent that tend towards a warmer color temperature as they are dimmed. Essentially what this means is that the light quality will remain constant when using LEDs that are dimmed. The only thing that will change is the quantity of light which is exactly what is desired from intentionally dimming your bulbs.

Building Exterior, Landscape and Decorative Lighting:

Lifespan Extension:

One of the previously unstated benefits of a low intensity operating environment (a dimmed light) is that the useful lifespan of the individual bulbs is likely to improve. The more time an LED light is operated at low current, the longer the lifespan is likely to be. Normal expectations surrounding operating lifespan assume the bulbs are operated at 100% power and typically estimated useful lifespans between 50,000 and 100,000 hours or more. The fact that these remarkable numbers can be improved even further by operating the bulbs at low currents puts LEDs in a lighting class all by themselves.

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Security Improvements:

Another advantage of adaptive lighting solutions like motion sensors is that they act as a deterrent to potential crime. Lighting levels that are dependent on occupancy both startle intruders and serve as an indicator for security patrols looking after a property. LEDs with a white light improve the visibility for patrols and may improve the effectiveness of security personnel to respond relative to their ability with a monochromatic yellow backdrop.

College Campus Quad Lighting Improvements With LED Lights

Features such as motion sensors and time sensitive light level programming can be integrated into all kinds of outdoor lighting (parking lot lighting, street lighting, building facade lighting, pathway lighting etc). The typical themes that make it effective include minimal obstructions such as trees, moderate height for pole-mounted sensors (20-30 feet or less) such that they are still in close proximity to objects moving on the ground, and low to medium traffic in the targeted areas (such that it actually makes sense to dim or even turn off lights at different times). For large projects these sensors are often synchronized and/or connected using radio frequencies. With the advent of smart devices this kind of network can now be managed both on-site and via remote internet access. Lighting schedules and alerts can be adjusted to meet the needs of a particular facility based on emerging information and/or changes in activity.

Ebook: 7 Different Lights LEDs Are Putting Out of Business


Conclusion: Energy savings and maintenance savings vary depending on the project particulars but generally fall around 60-70%. You can read a plethora of LED conversion case studies here or send us a message to get more specific information related to your particular need. We recommend working with an experienced lighting contractor to select the appropriate lights and the appropriate adaptive controls. Experienced distributors and project managers can help you save money and successfully plan the specifics of your project.

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