Just image you run a network of about 30 petrol stations. Business is going well, but energy prices for electricity increases constantly causing higher operating cost on your stations. And your big brothers like BP, ARAL, Shell, TOTAL, TEXACO, LOTOS, OMV, ENI, REPSOL, PETRONAS, etc. change their stations more and more to really nice and clean WELL ILLUMINATED stations. As a clever entrepreneur with a sense for marketing you call your sign maker and ask him to offer you a price for changing all you corporate design on the stations to state-of-the-art: as a result you will have much more light on your stations!
Now comes the bang: Just a single totem with about 6-7m height (which you definitly need to be seen well from distance) you get easily an average power consumption of 3-4 kW. This is because you need to use many, many T8 fluo tubes to get uniform backlighting. And most likely you wanna have a well illuminated totem...
If you run the totem about 11 hours a day, 365 days of the year, you will have an average energy bill of about 1300 Euros for only one single piece of totem! 3 kW * 0,11 € * 11 h * 365 d = 1.325 €
By the way: Because of all the T8 lamps inside, the totem is heating up causing the air absorbing more humidity. When turing of the totem, the humidity will drop as dewing or condensate. And in this case we are talking easily of LITERS of water inside your nice new totem which will mix up with all the little insects and animals that got inside the totem because of high level of UV light. This water-insects-cockail burns then the next day into the acrylic glas when the totem is turn on again when heating up again inside. And all the street dirt, salt in winter, dust, etc. not mentioned...
So what to consider when illuminating a fuel station totem?
From energy saving point of view you will need to change from fluo tubes to LED. It will anyhow fit in your corporate CSR (=corporate social responsibility) strategy. Use LEDs also because they do not emit UV light.
So which technology to use? LEDs from China? Europa? US? LED Chains? Single High-power modules? Linear LED Luminaires? etc...
Well, the market will offer you already a rich set of prooven technology. And the focus in my last sentence is on PROOVEN. Force your sign maker to proove the LED they used by letting him show you big outdoor reference projects with already more than 1 year operating time. Talk to the owners of the project and make sure to get their impression of using LEDs.
On the product side, one criteria is outdoor readiness of the LEDs.
So IP67 rating is an absolut must, in regions with temperatures below -30° (Russia) or higher than 45° C (Middle East) check the LED manufactures specification or datasheet. Most likely you might pay some money to an external light laboratory which should verify the data in these specs, as many LED suppliers put their optimum values into their datasheets - and not the real live average parameters.
Another focus should be lifetime: when comparing lifetime values be sure to compare them for the same ambient temperature (ta) or tc point.
And the housing of the LEDs shouldn't be out of epoxy material, as it is just cheap but not very useful material for your application (in worst case it will change to granulate after some month, beside a leaking housing of the LEDs, corrosion will be the result on the PCBs of the LEDs causing 100% failure rate).
Also the acrylic glas (know also as PMMA) should be optimized for LED light source: when changing from classic fluorescent tubes to state-of-the-art LED technology use some LED optimized acrylic sheets (Evonik TrueLED or Altuglas LED System). These new PMMA contains more additives resulting in higher diffusion level. So you won't see any LED light dots through the acrylic.
Position of LEDs? Before thinking of positioning LED lightsources inside the totem, I strongly suggest to spend a night on a clever frameless design of the totem. As a result you will have no shadows from inside steel construction on the acrylic glas and benefit from perfect uniform backlighted designed totem.
Normally a fully backlighted totem has a depth from typically 0.3 - 0.5m. When you plan to use single LED modules which are put together in chains, this will cause some more labour or manual work: every little modules needs to be placed. So you also might to ask for some good linear solution with latest LED technology like Poster Box from Philips or TALEXX engine IMAGE premium (IP67 rating) from TridonicAtco.
When placing such linear LED bars into the totem, make sure not to put them to far away from each other. As a rule of thumb 1m as a maximum distance between to linear LED bars. Such solutions only work with internal reflections to result in good uniformity. This means, that the inside steel frame construction needs to be designed well in order to minimize inside shadows. So you still might want to use some single LED chains to illuminate the areas where the linear LED solution does not result in good uniformity on the acrylic.
With this considerations you should be able to rock solid evaluate you brand new design propsal from your favourite sign maker...
Friday, 1 October 2010
Thursday, 10 June 2010
This picture shows the layout of led modules in a petrol station totem. The trick is to do the optimization in depth and distance between the modules while remaining unifomity on the backlighted acrylic glas, because the less LED modules you need, the better will be the price for your customers...