Lighting Design – It’s a difficult choice (Part One)

As promised this months trek really is going to try to spell out the main differences and myths that surround various lighting technologies which are being used in museum, retail and office environments.

Let’s start with LED’s as they are certainly the relatively new boy on the block and in my view the way forward for most new lighting design installations.

I have recently read articles by other lighting design experts on this very subject but I think most of the claims made in these articles are a little or sometimes a lot exaggerated about the amazing energy and cost saving qualities of LED’s.

There is certainly energy and cost savings to be made when using LED’s in a lighting design but it is very difficult to put an exact figure on exactly what those savings might be?

You might also be making energy savings but how long will it actual take to recoup your initial outlay and at what cost to the quality of light?

I do feel that some of the energy and cost saving claims are certainly being manipulated or exaggerated in order that organisations, museum or property developers abandon their present systems to invest in these expensive lighting technologies.    

For example if we use what the manufactures claim is the same amount of light output  to replace a typical T8 ,1800mm, 70Watt fluorescent tubes costing between £3.50 an £4.00 with a 22 watt LED tube costing between £75 to £95 the difference in outlay is huge.

 I will let you do the maths on how long it takes to recover this initial outlay? Yes you can bring loads of things into the equation, the amount of time it take to replace a lamp and how many additional fluorescent  tubes you might require but what ever way you bring in, its not going to be overnight . I guess it would help to do the maths if you knew exactly how long the LED’s would last, no one can tell you that? Well again there are claims of 30,000 to 50,000 hours that’s more than 10 to 20 years when you apply a rough normal guide of use. But do they?

Bottom line on the energy issue and cost is really what value you apply to the factor of convenience. For me this is where LED’s really start to shine (pardon the pun). Assuming that the LED’s get near the claimed long life you can just install & focus then sit back and forget them and for every year that passes you know that eventually you will be in pocket and helping you to cut your carbon foot print. I just can’t tell you accurately how long that will take and I don’t think anyone else can either.

So that was the energy and cost issues now some of the other advantages and disadvantages surrounding LED’s compared to other light sources.

LED – Disadvantages

• LED’s used singularly run fairly coolly just warm to the skin but multiples LED’s together and run them at full power and they start to generate unwanted amounts of  heat which needs to be dealt with especially if used in a confined or sealed environment  like a museum showcase.
• Less choice of fittings although the gap is narrowing as manufacturers rush to fill the lighting void.
• Colour temperature (purple blue tints compared to halogen).
• Rendering
• LED’s need to be from the same batch when ordering so to keep continuity across the range. 
• Not good for lighting all objects or paintings especially if they have a high orange or red content.

LED – Advantages

• Lower energy consumption.
• Long lamp hours reducing maintenance and the need to re-focus light fixtures.
• Light emitted contains low infra-red levels and no ultra-violet.
• Size; enabling lighting of objects and areas where previously it wasn’t possible.
• Newer and better version are being developed all the time and at bit like the revolution in wide screen TV’s the more lighting designers and organisations buy into LED then cheaper and better lighting equipment will follow. 

Of course there is plenty more I could write but if I have learnt one thing whilst writing these lighting design blogs is there is no substitute for the knowledge, expertise and experience of a good lighting designer.  

When choosing lighting designer always check to see if they are independent lighting design consultants that aren’t tied to any lighting manufactures. This allows the lighting design consultancy or consultant to give clear impartial advise on what they think might suit your needs best.

At the end of the day if you want the very best quality lighting and can live with its continual maintenance, high energy consumption and refocusing demands then I would stay with Halogen. If however any of these is an issue and your old system is on its last legs then LED’s has to be the way forward or a combination of numerous technologies should be adopted.

For a nice change in “It’s a difficult choice Part 2” we will look at Fibre Optic Lighting and if it’s had its day!

DHALI\DMX