Hotels all over the world try to keep the energy used for the operation of the hotel – low, lower, as low as possible. Whilst in existing projects big energy consumers like air conditioning, heating, cooling (not to talk about the really big “wasters” like kitchen equipment) are difficult to change and most of the time too complicated and too expensive, lighting seems to be an easy part to change and to save money immediately.
Lighting in hotel project use approx. 20% of the total energy needed to run a 4-5 Star Hotel; so the public areas use even less than 20% seen within the whole project consumption.
Lighting or better LAMP-manufacturers promise Hotel operators to save 80% of this energy use if they change existing incandescent and halogen lamps to LED reftrofit lamps. Promising an easy change and “exactly the same lighting”, they preach to the converted in hotel managements, as this is exactly what is needed.
Unfortunately, what is often the case, is that the promises do not come true!
There are many problems to think about when changing the existing bulbs to reftrofitlamps, which cause disappointing results in all fields of lighting.:
First and worst promise is the lifetime! “50.000 hours lifetime and more!”
are promised in the market, but the LED has, besides some other technical specialities – a problem with heat. LED sources produce heat at the LED board and they are highly sensitive for a board temperature higher than 100C°. If the LED gets to warm lamp life goes down extremely, light output goes down and if the board gets hotter than app. 130° the LED dies.
So it is very important that refit lamps are designed very precisely in terms of heat management and heat reduction. Most of the reputable manufactures like Osram, Philips, GE, promise only 35.000 to 45.000 hours for their refit solutions, because of this heat problems. And if a cheap product has been purchased, the lamp life could be much lower than this. With this the promised payback is lost because the lamps have to be replaced. It is easy to promise 50.000h when you sell – you can be quiet far away after already 15.000hours of operation time 😉
Second promise: “Savings of about 80% of the energy!”
Most of the existing retrofit lamps for e.g. the halogen low voltage lamp, which are really use in billions in Hotel projects all over the world, do not reach the same light output. It is easy to compare – if you look at luminosity (candela) it is easy to realize, as you can compare 1 to 1 if you chose the same beam angle: A halogen low voltage mr16 – 24° – 35Watt has 4100 candela* luminosity output and the offered “equivalent” refit mr16 – 24° 7Watt has only 1000 candela*. This is physics – less light output gives less light – so you save 80% energy but in this case also 75,6% lot of light! Seen the other way around it means, you need more lamps/luminaires to keep the existing light level (important e.g. in meeting rooms, conference rooms, ballrooms).
Third promise “Just change – easy going”:
Let´s continue with the example of the mr16 lamps:
All – or most of them – are on dimmers, integrated on a dimming system. The problem with the LED me16 retrofits is, they do not function with every transformer and every dimmer system , sometimes the lower wattage causes problem with the transformer (underload). The result is flickering light, broken transformers and in worst case broken control equipment.
If you are lucky and the transformer and the retrofit and the dimmer “speaks the same language”, means LED retrofits work properly with transformer and also control system works good, then you have to do a complete new programming, to get the same lighting scenarios like before – because the light output is different!
So what about “easy change”?
In between I think I need to state clearly that I am not against LED and also not against Refitting existing projects – but I think it is important to name the“real life” problems!
Coming to the forth promise, which touches me as a lighting designer and probably I am speaking for hundreds of us, we have to talk about “You get the same lighting!”
Regarding the lighting levels we have already seen that there is a big issue about lighting level – but lighting level is not everything: lighting creates the atmosphere of an entire space. In one and the same project you have a lot of different lamps – lets keep on with the mr16. In some areas you need a focused light with a narrow beam angle – and in other areas wide beam angles are used. This creates differentiated lighting atmosphere and different lighting zones. If the lamps are changed now – without thinking about this, or without paying attention to this particular specification, and that is the standard procedure in refit business, you have the same light distribution everywhere. Atmosphere is gone, lighting atmospheres are completely different and loose their original design intention and room impression.
And – not to forget the light quality – the Led refits often have a very low colour rendering from about 70-85% – halogen has 100% – and then you will never get a light as brilliant from an LED as you get it from halogen (never say never,…J), besides a poor colour stability (within one lamp type you can have big differences in colour temperature) So this is also a loss in light quality. In some parts of light quality we might need to make a compromise, looking at the sustainability of a project.
All these “lost” promises are even worse the cheaper an LED refit is – produced by a new ‘”green’” company, without a proper heat management and with no knowledge about colour rendering and colour stability.
Seems that all this ends up in unfulfilled promises?
Not necessarily – with these explanations I would like to show the difficulties that are found when relamping or refitting existing luminaires – which are not shown by the manufacturers who want to sell refit lamps.
In our position as lighting designers it is really a problem, that there is such an aggressive Market, lying about lamp life, light output, light quality, promising an easy solution an raising customers´ expectations.
In most of the time investors or Hotel owners did put a lot of money in the interior design, materials, the lighting system, and also paid an interior designer and lighting designer to create the warm and nice atmosphere needed in the particular areas.
With this, lets name it, “quantitative refitting” all this investments, plus the new investment for the refit itself – are wasted, as there is only a theoretical payback. It is decreased by lower energy savings and shorter lamp lifecycles and by additional costs, such as new transformers, reprogramming etc., together with a loss of light quality and interior atmosphere.
That is why I think it is important that operators, engineers and general managers are aware of the problems mentioned above, to ask for a proper refit planning, looking at all these aspects, which are important to keep the payback and the light quality. Lighting designers and consultants can organise a sufficient relamping, such as the hotel´s technical engineers can, by examining the existing system, light sources, beam angels, dimming facilities and can calculate a realistic payback period – and – based on that decide where it makes sense to relamp now – or where to wait for a better generation of LED refit lamps.
Considering all these “specialities” in the relamping process, one will create a real sustainable project by getting a realistic payback, a proper energy saving, besides keeping the original lighting atmosphere and room impression – meaning:
protecting the investment.
So – LED relamping ?
YES we can!
With a particular knowledge and the awareness that you don´t always get what you’ve been promised, but that you always see what you got!
Halogen – Osram – DECOSTAR 51 ECO 35 W 12 V 24° GU5.3
LED – PARATHOM PRO MR16 advanced 35 24° ADV 7 W/827 GU5.3
All rights by Katja Winkelmann, Licht01 Lighting Design
President Elect of Professional lighting designers association.