Challenging the regulations
Better controls would do more to reduce energy consumption for lighting than pushing efficiency requirements for lamps and luminaires to unrealistic levels, agues Liz Peck.
Part L of the Building Regulations for England & Wales (and its equivalents in Scotland and Northern Ireland) is the principle requirement for governing energy use in buildings. Their core purpose is the ‘conservation of fuel and power’. However, the lighting industry is united in the view that they don’t go far enough in achieving this objective and is calling for a sea change in thinking.
For years now, the standard measure of efficiency for lighting has been based upon luminaire or lamp efficacy, presumably based upon the notion that if the source is efficient, then so is the installation.
Casting aside the discussion on whether 55 lm/W (that’s circuit watt), whether that’s luminaire or lamp, is really ‘efficient’ for one moment, the lack of importance placed on controls is arguably its largest flaw. Current controls recommendations allow luminaires to be left on at 2 a.m. in a deserted building. It’s often said, but the most efficient luminaire is the one which is switched off— so how can a measure of luminaire performance on its own be a measure of efficiency? Of course it can’t — which is why change is needed.
A decade into the 21st century, photocells and PIRs are still being treated as advanced lighting controls. The application of a controls factor if they are utilised effectively drags the luminaire and lamp efficacy targets back to the 2006 level of 45 lm/W.
In ever-changing technological times, few lighting designers would describe an absence detector or photocell as anything akin to advanced. Most designers, in fact, would start to wax lyrical about Bluetooth, IP addressing and charge-coupled devices — and these are just potentially small component parts of a larger building-management system.
Even in the domestic market, there is an ever-increasing awareness of the flexibility that lighting controls bring. Few parents would turn down the opportunity of having a ‘childproof’ lighting control which saved the interminable shouts, ‘Turn the lights off!’ being ever repeated again. In fact, domestic users are adopting lighting controls, often integrated with audio-visual systems, far more than is widely acknowledged. The opportunity of being able to control lighting from a mobile phone, even from a beach in Marbella, to thwart would-be thieves is becoming increasingly popular. So if sophisticated control is being adopted by the wider public in new and refurbished homes, why is there still an issue commercially?
It could be argued that part of the problem lies with the designer’s worst nightmare: value engineering. VE, for the blissfully unaware, is the point at which designers would say that the quantity surveyor removes all the best parts of the design, supposedly in the interests of cutting costs. Sadly, some lighting controls go into the great VE bin in the sky. The fact that those very same controls would have reduced energy consumption and long-term cost is irrelevant, the QS is interested in the capital budget alone.
The Government is somewhat reluctant to make lighting controls, even those as basic as absence detectors, mandatory, so another approach is needed to really drive lighting energy consumption down. The answer lies in an integrated design solution, a move to a systems-based measure that fully reflects the use of controls.
If Part L adopted energy-consumption targets for lighting, then it would change the emphasis away from the individual components and instead focus on drawing those components together to ensure a truly efficient lighting scheme. It’s not rocket science. Which is more efficient — a luminaire of 100 lm/W alight in an empty building or one of 40 lm/w switched off because controls have been properly applied?
We already have a measurement tool at our disposal in LENI (Lighting Energy Numeric Indicator) which allows us to predict and benchmark the energy efficiency of lighting schemes, so implementing controls properly wouldn’t be difficult.
It might be argued that such an approach won’t be as easy as the current methodology, but these are challenging times, globally, when it comes to energy. It’s time for the Government to lay down the gauntlet and start challenging lighting designers to design energy-efficient buildings; after all, it’s what they’re paid to do.
Liz Peck is secretary of the Society of Light & Lighting.
