LED colour shift problems and what to do about it

So your lighting design practice worked hard on the site survey, submitted a well thought through offer and won the order.  Your suppliers delivered on time and your contractors executed on the installation to specification and budget.  Your client is happy and life it good.  But then, just when you are working on your next lighting project you get a call from the client saying that “we’re noticing strange colour differences across the luminaires”.  So you go and visit the installation and yes, you can’t disagree.  They were all supposed to be 5000K luminaires but they do seem to fall into two differing colour bins.  How can that be?  Calls to your supplier begin to raise alarm bells with defensive statements like, “well of course there will be slight variances from fitting to fitting”, “your customer is being picky”, or “tell them that this is normal.”

So now what?

Is the customer being picky, you wonder as you review the specifications of the products you sourced.  Has the supplier provided you with LED’s from the same batch?  Are they even 5000K?

Questions Questions Questions

You need facts. But where to get them.  You could remove a selection of the luminaries and send them to a lab.  But how many and at what cost?  What about the disruption and inconvenience to the customer?  What to do?  Numerous follow up meetings simply add to the questions.  “What exactly did we order? What were the tolerances on colour temperature?  Did the LED’s shift sometime after installation?  How was the installation validated?  What data do we have?

Regrettably, occurrences such as these at not rare.  Without an accurate way to verify incoming material to formal specifications and confirm performance post-installation, there is only guesswork.

Spectrometer measure LED colour shift

The advent of technology advances in LED lighting has brought enormous choice in terms of light quality, control and energy efficiency. However, LED lighting is a very different light source compared with traditional lighting. Facility Managers, lighting installers, specifiers and lighting designers alike are now faced with spending more time in product selection and validation. The Asensetek Lighting Passport, a commercial lighting spectrometer is a convenient, affordable, reliable scientific tool to make accurate measurements of lighting performance for Colour Temperature (CCT) and Colour Rendering (CRI, Ra, Re) including the latest TM-30-15 standard.