Wednesday, 23 November 2011

A cautionary tale from LED land

Once upon a time there was a young property investor who decided to build a hotel. His hotel was in a busy, business area near London. He wanted it to be very fine and worked with a big hotel chain to design it to meet all their standards. But he wanted more than that; he wanted his hotel to use LED lighting technology. He loved the idea of low energy bills and he envisioned some really 21st century lighting effects in his new hotel. But he knew it was a complicated thing to do – and he respected the challenges new technologies could bring – so he found a special wizard (LED consultant) and shared his idea.
“We can do this, and we can do it well” said his wizard, “here is a design, and a plan and list of exactly the right lights to achieve your dream”.
“Fabulous”, said the young man, “let me show it to the project management company”.
So the project management company looked at the plans and said “We need more: more graphs, and more pictures and more meetings”.
They had more meetings and looked at CAD models of the lights and talked about dimming protocols. And then one day, co-incidentally, they went bust and vanished.
The young man found another project management company. He introduced his LED wizard to them and showed them the design and the plan and the specifications.
“Oooh!” said the new company, sucking their teeth, “we need even more details and meetings and designs.” Which the wizard and the young man very politely provided.
And  then everything went silent.
The LED wizard was worried. The young man’s dream for his lights was not going to be realised in time if they didn’t order the lights before the building was finished. So he rang and emailed the new project management company.
Then one day the new project managers said “Look how clever we are: we have found lights just like the ones you told us about – but they cost much, much less”.
“Are they really the same?” said the wizard – “I’d like to see them.”
But the man who had made the new lights got very angry “ARE YOU CALLING MY LIGHTS RUBBISH?” he shouted, “MY LAWYERS WILL BE CALLING YOU.”
The LED consultant was a brave soul and gently suggested that the young man, the project managers, the designer, the new light supplier and anyone else interested should all get together and turn on the lights to see what they were actually like.
So everyone met in the half-built hotel and they turned on the lights: they looked at the new lights and they looked at the lights originally specified. There was silence.
The project management people said “Wow! We didn’t realise that despite having the same wattage and lumen output the difference between two LEDs could be so big. The beam angle is different, the colour is different, the light temperature is different, the fall of light on the floor is different and they have different life expectations.”
“ARE YOU CALLING MY LIGHTS RUBBISH?” shouted the angry man who had made the new lights.”MY LAWYERS WILL BE CALLING YOU”.
“Well, no,” said everyone, “but we can all see that they will not deliver the design as specified and don’t even offer a close compromise. The young man – who ultimately pays for all of this – will not be getting what he wanted.”
And between each other they wrote many emails blaming and shaming and worrying because they had already ordered masses of the wrong lights.
In other stories someone would appear now with a wand, or a horse or, even a princess – but in our story we still don’t know whether the dimming protocol will work with the LEDs chosen in error – let alone if the young man will get to have his vision realised... another chapter to follow...

Tuesday, 15 November 2011

LEDs – anticipating the pitfalls and identifying the risks

LED lighting remains unregulated “Wild West” technology with great potential but some enormous risks.

These were poor quality LED’s that had to be taken out of a misguided hotel recently. This is one of three boxes!

Risks:
·         Buying LEDs that fail
·         Buying LEDs from specs and not witnessing the light
·         or change colour after a little use,
·         or start failing because the dimmers are neither compatible or dim
·         or the replacements are not be the same as the original batch
·         or that don’t do what the designer specified
·         or that don’t send out the right colour of light

You cannot send them back because you do not “like” them and expect a refund.

The failure of a light to deliver to the specification may also not be immediately apparent unless every detail is investigated.

This designer specified downlights with a medium beam and lumen output of 600 Lm. The contractor went for a cheaper model which purported to have the same lumen output and beam angle. Unfortunately this was being delivered at the expense of the beam angle (which was much narrower than claimed) The result is this patchy, mottled effect on the floor – not what the designer or client wants to see at all.

How then to avoid the pitfalls?
·         Start with a lighting design that suits the technology.
·         Model the lighting levels to illustrate where the light will go and how good is the light throw
·         Specify lights that you trust will deliver the light for a guaranteed period
·         Ensure trace-ability in the event of failure
·         Establish what are the options at end of life
·         Check that every component of the light will deliver every aspect of the design to the required level. Where you are considering between two apparently identical lights TURN THEM ON and then see how they perform.

If you do not have access to this expertise, use an expert LED specifier and also use an LED experienced electrician. Many claim experience in this technology, few genuinely grasp the issues. Any investment in LED involves a great deal of money. Take care.
Buy the right effective LEDs and you have great lighting for a generation using a fraction of historic energy.

Ian Peter MacDonald  -                MacDonald Tait Light -                November 2011 -  ianpeter@macdonaldtait.com