LED lighting is the new solution of choice in the pool and spa industry

by Sally Bouorm | October 1, 2010 11:04 am

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By David MacCallum

In recent years, light-emitting diode (LED) technology has been embraced by the pool and spa industry. While LED technology used to be an expensive, specialized alternative, today’s pool and spa fixtures are brighter, more energy efficient and less expensive than their first-generation predecessors.

Designed to last longer and consume less energy than traditional alternatives, LED lighting options are becoming increasingly prevalent in pool, spa and water feature applications.

A brief history of LED

The technology has been around for almost 50 years; the first practical LED was developed at General Electric Company in 1962 and became commercially available in the late 1960s.

LED devices convert electronic energy directly into light, the brightness of which can then be controlled. The main component of an LED is a chip of semiconducting material modified to create what electrical engineers call a positive-negative (p-n) junction. Current flows from the positive side (anode) to the negative side (cathode), only in that direction. Electrons and holes, both of which carry a charge, flow into the junction from electrodes of varying voltages. When an electron meets a hole, it falls to a lower energy level and releases excess energy in the form of a photon. The wavelength—and, therefore, colour—of the light emitted when the electron meets the hole depends on the energy gap between the materials that form the p-n junction.

Early LEDs were red, first used as replacements for incandescent indicator lights in expensive laboratory equipment. As production costs decreased and they became more affordable, red LEDs began showing up in electronics such as remote controls, TVs, radios, telephones, calculators and watches, still serving as indicator lights (they were not yet bright enough to provide illumination). Later, other colours became widely available and were used in appliances and equipment.

Eventually, as the technology continued to improve, light output and brightness increased, opening the door to illumination applications. Today, LED technology is used for a wide range of purposes, including airplane navigation lights, traffic lights, children’s toys and automobile headlights and turn signals.

Testing the waters

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For many years, fibre optic lighting was the technology of choice for creative spot colours, multicoloured underwater light shows and water features. These effects could also be created by placing a lens, or rotating set of lenses, over a white halogen or incandescent light. While these technologies are still available, LED market share is increasing, thanks to reduced costs and development of more user-friendly fixtures for residential owners.
The swimming pool, spa and water feature industry is increasingly turning to leading LED manufacturers for both white and colour LED fixtures that not only offer bright illumination, but also present new opportunities for dynamic, choreographed light shows. Landscapers also have access to LED technologies; in fact, with the right controls, landscape lights can be synchronized with pool, spa and water feature lighting to unify a backyard setting.

LED technology is also at the heart of some of the industry’s newest illuminated arcing laminar-style water features, which carry graceful arcs of water in different colours through the darkness. These features are made possible by the size options provided by the technology; for example, LED fixtures can be as small as a pencil tip (one diode) and can therefore be installed in tight spaces. In fact, early pool industry adopters of LED technology often used them in steps, fountains and other specialized areas, where a small amount of light is beneficial.

An increasing number of commercial pool operators are also switching out incandescent lights for LED fixtures in order to save on energy consumption, technical service time and expense. Depending on the number of lights and the hours per day they are in use, the return on investment (ROI) for an LED upgrade can be as short as one year.

The bottom line

The savings come in two forms. First, LEDs consume less energy to provide comparable amounts of light. They also allow for brighter light given the same amount of energy use. For example, some LED fixtures use upwards of 86 per cent less energy than comparable incandescent lights to provide the same amount of illumination.

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Secondly, they last longer and do not need to be replaced as frequently. This is, in part because LEDs, unlike incandescent lights, use solid-state technology; they have no internal filaments that can wear out. As a comparison, an incandescent bulb rated for 2,000 hours will last just a few months if used eight hours a day. LEDs, on the other hand, can last up to 10 years or longer. In the residential pool market, where pools typically use fewer fixtures for fewer hours, recovering the costs of an LED upgrade may take longer, but the benefits are still the same.

Another benefit of this lighting technology is its running temperature, which is also related to energy consumption. Heat shortens the life of any electronic device, and LED lights are no exception; however, LED fixtures run much cooler than incandescent and halogen lights, simply because they use fewer watts. Although models and designs vary, an LED fixture can emit as much light as a 500-watt incandescent bulb, but consume only 70 watts.

Even though LED fixtures run cooler compared to other lighting technologies, they still generate some heat, prompting lighting manufacturers to use thermal management techniques to keep them as cool as possible. In other words, LED fixtures are designed so the heat they generate is drawn away from the diodes.

A matter of esthetics

In addition to these practical benefits, LED fixtures also offer certain esthetic advantages. For example, the ‘white’ light one gets from an incandescent fixture has a yellow or green tinge to it; in contrast, a white LED fixture has a cool blue tint. The human eye is more sensitive to blue at night, so LED whites tend to appear brighter, crisper and cleaner.

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Further, LEDs offer a broader, brighter and richer colour palette because they use the additive properties of light (as opposed to filtering out, or subtracting, colour from white). Thus, all the energy is going to generating the desired colour. With technologies that start with white and subtract, some energy is wasted.

There are two ways to make LED fixtures cast different colours. One is to control how many diodes of each main colour—red, green and blue (RGB)––are on at any one time. For example, to create a purple light, all the green diodes may be turned off, allowing the red and blue to combine. To switch to a pure green tint, the reds and blues would be turned off, while all the greens would come on. Using this approach, any colour combination is possible.

The other approach to colour mixing is achieved by varying the current to each of the RGB colour arrays. This is most often achieved by pulse with modulation (PWM). The controller for PWM colour mixing may be an external unit or part of the lighting unit itself.

In recent years, some LED pool and spa lights have been designed with special lens geometry and reflector design that delivers brighter, more uniform light distribution than earlier products. Some newer products also have special lenses that can be rotated up to 180 degrees, providing a wide or narrow beam pattern. This added design flexibility is also contributing to the growing adoption rate of LED technology for pools.

Keeping up with design

Swimming pools have become more complex in recent years. Anyone who is building a new swimming pool today is probably investing a lot more than was typical 10 or 20 years ago. During the pool building boom of the 1980s, the average pool may have been a $30,000 or $40,000 project. Before the economy slowed down, the average pool price was much higher, arguably double. While fewer pools are being built today, the people building them (or upgrading existing pools) tend to want the most technologically advanced and energy-efficient options.

Poolscape design trends are also well suited to LED technology. Roughly 15 or 20 years ago, most pool surfaces were smooth and white, reflecting light very well. As such, they used less energy to achieve proper illumination. As darker pool surface colours and textures—which absorb light, rather than reflect it—started becoming more popular, designers began looking for different lighting options.

Depth also affects brightness. If you illuminate a pool’s deep end and its shallow end with the same amount of light, the shallow end will glow brighter. You see the same effect from sunlight as you fly over natural bodies of water. Having a lighting system with nearly infinite adjustment possibilities—which can be achieved with the right combination of LED and digital communication technology—increases the pool owner’s degree of satisfaction with the finished project.

A final word

As pool and spa builders, owners and operators seek out more ‘green’ alternatives, and look for ways to save money on increasingly complex installations, LED lighting offers a wealth of possible advantages. As manufacturers continue to offer more options and flexibility, the switch to LEDs will be easier for those looking to add a little light to their pool, spa or water feature.

 

David MacCallum is the senior global product manager of lights and automation at Pentair Water Pool and Spa in Sanford, N.C. He can be reached via e-mail at david.maccallum@pentair.com[5].

 

Source URL: https://www.poolspamarketing.com/trade/led-lighting-is-the-new-solution-of-choice-in-the-pool-and-spa-industry/

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