Pool and Spa Lighting in Aquatic Centres
(This article was published in the Australian Pool + Spa magazine Jan/Feb 2015)
A Pool Lighting Case Study….
Let’s face it, without lighting; even the most beautiful pool would not stand out at night. But even during the day pools and spas in aquatic centres and water worlds look quite dull and boring without good decorative and functional lighting.
So, what is the purpose of the lighting? Basically you can break it down into three categories:
• Task: that is the purpose of the general lighting
• Beautification: the objective of the pool, spa and landscape lighting
• Safety: for swimmers that is a combination of the general lighting from the ceiling and the pool lighting
The most neglected lighting for public in- and outdoor pools and spas is the underwater lighting, which is our primary focus.
Let’s use, as a Pool Lighting Case Study, the German example of the Carpesol Aquatic and Recreational Centre. The 19m Euro ($27m) project was opened mid last year to the public after a 21 month construction period. It combines training pools with leisure pools and saunas into a world where you can be active or just relax. With 10 different pools and spas, 4 saunas and one steam bath, the centre has something to offer for everyone.
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In order to create the right atmosphere, coloured RGB lighting was used extensively within the pool, as well as throughout the surrounding areas in this Pool Lighting Case Study. With the availability of LED light sources, coloured light and light changes are easily managed. With DMX controlled lighting, it is easy to achieve the desired results, as the controllers can programmed to set and recall static and dynamic scenes. In the first picture, you see powerful 85W RGB underwater LED lights in the pool, smaller 28W ones in the fountain and surface mounted spot lights in the upper half of the dome. For the fountain and dome illumination different colours are used in comparison to the pool and the surroundings to achieve a colour contrast. It is an easy task for the operator to adjust this with the help of the DMX controllers.
In this Pool Lighting Case Study for the large outdoor pool very powerful 115W RGB LED fittings were used to illuminate the pool, with the side effect that the stray light from the pool illuminates the adjacent building. (Picture 2 and 3) The lighting designer chooses a wide light beam distribution and as a result a homogenous illumination was achieved. With the high wattage LED fittings the illumination levels are elevated without any dark spots with the advantage in regards to safety of a clear visibility of the swimmers at night.
These pool and surface mounted lights and the colours are controlled from a remote location and pre-programmed scenes can be re-called. One setting is a very slow automatic transition from one colour to another. Another one is a static coloured scene setting. Important was the choice of the correct light beam spreads, the suitable power of the light fittings and a control system that allows changing the scene easily by the user. This would not be possible with halogen lamp technology that has previously been used, until some years ago.
The availability of long lasting and energy saving LED lights paves way for a truly “fit and forget” solution. A typical quality LED fitting has a L70 rating of 50,000hrs which means that the original light output is down to 70% after 50,000hrs. To take this in perspective this would be after 11.5 years with a 12hr daily operation -but the light is still working after that time. As a prerequisite, it is fundamental to choose quality fittings made of 316L stainless steel to avoid corrosion problems like tea staining, the usage of quality special underwater cables, and a fitting design which ensures long lasting water tightness. These material requirements are not only important for the fitting itself, but also for the installation housing.
In regions with high temperatures and pools with sea water, it can even be necessary to use higher alloyed steels such as 904L, to avoid discoloration of the 316L steel.
Often forgotten is, that with these long life expectancies of the LED fittings the life of the connected electronics must match: quality, long-life driver and controls are important as well.
Another consideration for pool lights in public aquatic centres is the location of the fitting in regards to the pool wall. By using recessed, flush mounted fittings with a thin rim thickness for the pool lights, the fittings cannot be used as a step by pool visitors, avoiding common future damages to the fittings. A similar solution is necessary for pools with moving floors which are used for several different purposes.
A carefully planning of the positioning and light beam direction of the lights in and above the water is essential to avoid glare to the visitors by aiming away from the main public areas.
In regards to the lighting design, in general there are several parameters you can choose from to achieve the desired lighting concept as in this Pool Lighting Case Study :
• Light colours for white light: warm white, cool white or daylight
Daylight white is a bluish white and creates a crisp colour rendering; warmwhite on the other hand is more yellowish and looks like a halogen lamp light. Cool white is in between. In most cases the daylight white colour is chosen but depending on the pool surroundings the others can be more appropriate.
• Static solid colours
A very popular static solid colour is blue because it resembles the ocean under bright sun. However, green can also be suitable for some pools. In the past this was achieved with Halogen lamps and colour filters, nowadays the LED fittings in most cases don’t need a filter anymore. Without filters you get more light or use less power.
• Changing colours
RGB (red/green/blue), RGB-W (red/green/blue/white) or RGB-A (red/green/blue/amber) is the LED technology for lighting fittings with changeable colours. Single lights or groups of these lights can be set to static scenes or dynamic, playing a programmed scene. With RGB-W you get a true white and all possible colours, with RGB-A you achieve a fuller colour pallet with very saturated warm hues.
With the newly available LED fittings with multi-colours, you can produce hundreds of colours from one fitting. The better light fittings can be controlled with DMX signals, which is a standardized signal and therefore can be connected to any DMX controllers. From simple wall mounted controllers, remote controls and to computer run controls, everything is possible. In most cases, a choice of different set scenes and one or two dynamic scenes is all that is needed. This can be easily integrated with the landscape lighting and also effect lighting for common areas.
• Light beam spreads: spot e.g. 10 degrees, medium flood 30 degrees or wide flood 60 degrees
With the available choices of different beam spreads, you can achieve very different effects. With a couple of underwater spots with a narrow beam spread you can create dramatic results with beams shooting through the water, or with flood lighting you are able to design a homogenous glow of the pool without any dark spots. The result is very different, dramatic with narrow beam spots or elegant with wide flood fittings.
• Oval beam spreads for shallow pools e. g. 45 degrees x 15 degrees
An oval beam spread is very useful for shallow pools. In this case, you use the 15 degrees in the vertical plane and the 45 degrees in the horizontal plane to avoid light losses caused by the light hitting the floor and the water surface too early travelling through the water.
• Multi optic spreads for high power lights to have flood and spot integrated in one light
A beam distribution with two superimposed beam spreads is very useful for big pools, where you have to use high LED wattages. It is a light fitting with two different integrated light optics in one light. A flood characteristic illuminates passing swimmers which are close, whereas the spot reaches far into the pool.
It is not always necessary to use powerful lights to illuminate the entire pool. Especially for smaller pools and spas one option is to install small lights which have only a decorative purpose but don’t illuminate. In these cases 1 – 5W LED fittings is all what is needed. In the same category of decorative pool lighting are waterproof LED strips with IP67/68 ratings, more decorative than illuminating. These special LED strips are also available in all whites and RGB. They can be used as a slim, linear, decorative element.
A last word about pool safety and visibility: A common problem is for indoor pools that the general lighting above the pool creates reflections on the water surface. Therefore it is often difficult to see below the water surface and identify swimmers which are in trouble. A good pool illumination can drastically enhance the visibility of the swimmers for visitors and life guards.
The lighting of aquatic centres and public pools is not limited to the functional general lighting but the beautification of the pools, spas and surroundings with a suitable illumination. The illumination plays an important role for the overall appeal of the venue and can even increase the safety for the swimmers as shown in this Pool Lighting Case Study .
Author: Dr. Walter Wendel, Form and Light Pty Ltd, Authorized distributor for WIBRE underwater lighting
Copyright pictures: Project: Carpesol Gesundheitsbad Bad Rothenfelde, Germany; Planning: Architekturbüro de witt janßen partner, Bad Zwischenahn