Pool Lighting Design for commercial and upper-market residential Pools
With the introduction of LED’s as light sources the possibilities for attractive pool lighting designs are endless. From the availability of different white light colours to all RGB or even RGBW colours combined with flexible controls. Together with energy savings and a long maintenance free live, LED pool lights are the preferred solution nowadays.
So what can you do with modern pool lighting and what should you consider for your pool lighting design? Here are some thoughts:
Most important but sometimes forgotten is that you cannot design a pool lighting in isolation without taking in consideration the lighting design of the surrounding pool area. One of the reasons is that the light levels of the surrounding area have to be at a level that the pool lighting still can compete with it. This is also a safety aspect and the main complaint from life guards is glare from ceiling light fittings on the water surface. Keep in mind that pool light serves 3 main tasks: illumination of the pool floor and walls, illumination of objects/swimmers and illumination of the water itself to achieve a certain glow effect. The latter is only possible because of particles and very small air bubbles in the water where the light is shattered from.
Indoor pool lighting design with WIBRE fittings
In this example the pool light has to compete with the strong general lighting and therefore the number of pool lights is high. The general lighting is indirect which reduces reflections on the water surface. The light distribution is around 90 degrees to achieve a uniform pool illumination.
The second very important fact is to start the pool lighting design for the pool areas early in the building design stages. When the concrete for the pool is poured and the installation housings for the light fittings are not incorporated it’s hard to change and concrete core drilling is necessary. Surface mounted pool lights for public pools are not recommended because of vandalism.Because underwater light fittings are hard to access for maintenance you want quality fittings and you want long lasting light sources, namely LED. Needless to say the IP rating should be IP68 with a specified maximum operating depth.
The fitting material should be stainless steel 1.4571/316L or for higher salt concentrations or warm salt water higher alloyed steel 1.4539/904L and also electro polished to further enhance the corrosion resistance. Contrary to popular belief stainless steel can in fact stain and discolour, in particular when incorrectly treated and finished.The same is true for the installation housing and all other fitting parts e. g. cable glands which also should be made from the appropriate stainless steel.
For the fitting construction it is important that the cable connection inside the fitting must be protected against water intrusion and also the effect of water wicking thru damaged cables and getting into the fitting must be intercepted. The gasket between the glass and housing should be only with aging resistant silicone material. The LED electronic boards should be protected with conformal coating.
Depending on the depth of the pool and also the light distribution of the fitting the installation depth of the fitting should be between 600 and 700mm and for shallow children pools 400-500mm. If the mounting depth is to shallow you will lose too much light which escapes from the water to the air before hitting an object in the water e. g. a swimmer. Only light which hits the water-air boundary below the angle of 41 degrees is reflected back to the water (total reflection). Also you will get a bigger black spot underneath the fitting. Installing the fitting too deep into the water will create a bright spot underneath the fitting and no illumination on swimmers close to the fitting.
The installation housing should have a flexible conduit from the installation housing to the outside of the pool and must have a watertight connection between the cable and the conduit – preferable on cable entry and exit – to avoid that water leaks out. Be aware that conduit without a water tight connection to the cable can lead to a siphoning effect even when the conduit is routed above the waterline.
The necessary light output per fitting for your pool lighting design depends mainly on the surrounding general lighting level and obviously on the size of the pool. Additional white light with higher colour temperatures has less absorption in water than warmer light colours. The reason is the typical absorption for blue of 5%, 3% for green and 16% for red after one meter of water.For other distances see table below.
| Distance from fitting |
2m |
4m |
6m |
8m |
10m |
12m |
| Blue % |
90 |
81 |
74 |
66 |
60 |
54 |
| Green % |
94 |
89 |
83 |
78 |
74 |
69 |
| Red % |
71 |
50 |
35 |
25 |
17 |
12 |
| White % |
89 |
80 |
72 |
66 |
61 |
56 |
Using LED fittings with higher colour temperature has therefore a double advantage: Higher LED efficacy and less light absorption in water.
A rough lumen output per LED fitting guidance is for an oblong pool width of:
| Pool width |
4m |
8m |
12m |
25m |
| Fitting lumen output |
For a strong lighting effect keep the general lighting below 100lx for these values.In all cases the pool lighting is located on both long sides with a distance between the fittings of half the pool width and a 90 degrees beam spread for a uniform pool illumination. Click on the lumen output above for suitable pool fitting examples. This compares very favorably with HID underwater fittings where you need roughly double the lamp lumen output to achieve the same effects. Reason is the typical LOR of a HID fitting and also the fact that a high share of uncontrolled light leaving the lamp will escape the water because of an angle between the water-air boundary and the light ray is above 41 degrees, as explained above.
The used cabling should be special underwater cable with a copper diameter as specified from the fitting manufacturer. If the fitting comes without a cable – to be flexible with the cable length – be sure to follow the manufacturer’s recommendations for sealing the connection e. g. with special compound. The same is true for water tight branch boxes and watertight connection and distribution systems. Preferable the cable should already be connected to the fitting in the factory and therefore the cable length has to be specified when ordering the fittings.
If you want to achieve stunning colour effects and at the same time achieve a real white light output you have to use RGBW LED’s that means individual controlled LED’s for red, green, blue and white. From full saturated colours to crisp whites and pastel colours in between. WIBRE offers now underwater lighting with RGBW for different models.
In regards to the light distribution of the fitting it’s the question if you want to achieve a more uniform light illumination or a kind of accent lighting. Or both? WIBRE offers different beam spreads from 10 to 90 degrees and also a “Multiflux” distribution which combines a very wide beam spread of 120 degrees with a spot distribution of 30 degrees. For shallow pools below 1.5m you would like to use an elliptical distribution, for example 15×40 degrees to avoid hot spots and light loss.
A small pool with 10 degrees RGB LED spot lights to create a dramatic effect.
A big pool with 90 degrees pool light on both long sides which are offset against each other to achieve a better uniformity.
In pool applications you rarely want to dim, only occasionally if you want to use the same fitting everywhere but don’t need the full light output in all cases.WIBRE offers therefore dimming solutions for many models.
But you want to have the ability to control the colour for RGB and RGBW LED underwater fittings. WIBRE offers you the possibility to control exactly that with DMX controllers. For most pool applications you want to have one controller, set different scenes which can be static or dynamic and also adjust individually. This can be easily done for the pool alone or together with the entire pool area. With a push of a button you can recall the scenes and set the pool area into that special mood lighting. Or do the same for different areas.
Very often the pool design includes certain water features from waterfalls, sheers to fountains or jets. Don’t forget to incorporate an effect lighting either from the bottom of the pool or from behind.
A stunning water fall feature illuminated from behind with surface mounted LED flood lights from WIBRE.
Unique underwater light fittings? Something new? What about linear pool lights? Or round or square underwater orientation lights? In LED, RGB, solid colours or whites?
Talking about light – what about sound in pools for example for water gymnastic, synchronized and recreational swimming? For sound transmission in pools you will need underwater loudspeakers which are available in flush or surface mounted variants. You will need one for every 25 to 40 m3 of water.
For pool maintenance it is sometimes necessary to lower the water levels or to empty the pool. Make the end user aware that high power LED light fittings need the water for cooling. Because of the danger destroying the LED fittings without the water cooling WIBRE offers most LED light fittings with temperature control feed back to the controller which lowers the power in these cases to avoid overheating.
The last things to consider are special pool requirements. Decorative small LED lights? Moving floors? You need flush mounted or recessed with only a small rim thickness. Saline pools? You need high alloyed1.4539 stainless steel fittings to avoid corrosion. Steel, fiberglass or foil lined pools? You need special installation housings which are all available from WIBRE.
Retrofitting an existing pool with LED light fittings? Call us and we can discuss customized solutions.
I summary – to design a satisfactory solution for your customer you want to use quality light fittings with LED technology to achieve energy savings combined with very low maintenance need.To achieve your intended design you want to have a lot of choices in regards of lumen output, sizes, light colours, colours and beam spreads. And you want to have all the accessories in the same quality as the fitting. Therefore I strongly recommend: WIBRE
by Dr. Walter Wendel
