Seeing the wood for the trees

The introduction of energy targets in support of the Building Regulations and other legislation is focusing minds very firmly on the efficiency of all of a building’s services and lighting is no exception. Achieving higher efficiencies in lighting requires a combination of more efficient luminaires better lamps, and improved control.

Of these three factors, better lamps and improved controllability have driven a virtual explosion in the variety of light sources that are now available. With the exception of GLS lamps, which seem to be on their way out, just about every class of light source now has a plethora of options to choose from – often varying from each other in quite subtle ways.

You only have to look at how the fluorescent market has developed in the last 20 years or so to see the trends in lamp development. In a relatively short space of time, linear fluorescent lamps have evolved from cumbersome, inefficient T12s, through analogue and high frequency T8s to the sleek, compact T5 that is now becoming the first choice for many projects.

In parallel, the compact fluorescent (CFL) market has come on leaps and bounds in terms of size, light output, efficiency and, very importantly, price. Technological advances have also increased the number of types of CFL available. As they get smaller they can be used to emulate more applications that would traditionally have been the preserve of twirly, swirly and candle-shaped incandescent lamps, opening the way for more efficient decorative lighting – often using fittings that are already on the market.

And while fluorescent may have seen the most rapid diversification, the same trends are very evident in metal halide, high pressure sodium and halogen lighting.

To further complicate matters, as the lamps have evolved, so too has the control gear and it is vital to match them up correctly. Often, there are several choices of gear that can be used with a particular lamp, partly due to the increased demand for controllability of discharge lamps mentioned above. All of which can have a significant impact on performance and lamp life.

End users may also have concerns about mercury levels in discharge lamps, so it’s important to be aware of which still use liquid mercury and which use mercury amalgam – and how much!

On top of all that, we are seeing an increasing number of LED-based luminaires, backed by significant hype about their capabilities and cost of ownership benefits. The result is that, in our experience, most LED lighting products fall far short of expectation and lead to disappointment – not to mention retentions and warranty claims.

Certainly there are LED-based products that can do a good job – but expectations have to be realistic. For example, it’s not uncommon to see lamp lives of 100,000, or even 250,000 hours quoted, but the reality is that in real life situations 20,000 – 30,000 hours is far more realistic – and even less at low ambient temperatures.

I have no doubt that these products will continue to improve, offering higher luminous efficacies, longer life and better colour consistency but until that happens we are very wary of recommending most LED products. At the end of the day, we would much rather recommend a light source that we know will deliver the required performance.

And this, I feel, is the nub of the whole lamp selection procedure. Determining which type of lamps will provide the right light levels in the right places is the bread and butter of lighting specifiers and what they do very well. Increasingly, though, they are expected to not just be aware of every light source that is on the market or may be on the market by the time the project starts. They are also expected to understand the implications of each in terms of cost of ownership and sustainability and make comparisons on that basis.

A few years ago it was relatively easy to do that because there were far fewer lamp types to choose from. Nowadays, understanding the lamp market and the characteristics of each lamp has become a specialist business that requires specialist knowledge – LEDs being a case in point.

To my way of thinking, this is where lighting specifiers can make better use of the expertise that is available to them through the specialist lamp distributors.

Companies like ours aren’t just there to ship boxes out of the door, anyone can do that. Our role in the supply chain is to add value through our knowledge and experience, making it available to those who simply haven’t got time to get to grips with every new light source. We even have specialist software to provide quick and accurate cost of ownership calculations. The resource is there – it seems a shame to waste it.

You might also like