The Need for a Lighting Review:
ItÃ¯Â¿Â½s common practice to reduce lighting design guidelines to the quantitative call for a specific level of illuminance, and in the process lose the (often qualitative and therefore potentially complex) recommendations that lie behind the numbers, which is a pity because possibilities for improved lighting conditions and reduced costs usually rest within those recommendations.
The obvious starting point for a review of this type is to interrogate this quantitative Ã¯Â¿Â½blanket designÃ¯Â¿Â½ approach. The illuminance figures stated in the SLL Guides are based on task-based criteria. But a task requiring, say, 400 Lux for its proper execution does not require the entire room to be lit to that same level. If the task is limited to one dedicated area, then the rest of the room is potentially overlit. Lighting in those parts of the room could possibly be reduced to just 50% of the Ã¯Â¿Â½designÃ¯Â¿Â½ figure.
This is a complete turn-about in lighting planning, but one that is gaining a lot of ground now that low-energy and sustainability practices is having such an impact on design thinking.
There is a further argument that develops out of the idea of planned, task-based, illuminance; because those illuminance levels are only required when the task is being performed, we donÃ¯Â¿Â½t even need that level of light in that particular space all the time. So why not investigate light level control as well as tightening-up on the location of enhanced illuminance levels. ItÃ¯Â¿Â½s no different to switching on a table lamp so that you can read a book while the rest of the family is watching the TV.
The third strand to this type of lighting design overhaul is to look again at the technology thatÃ¯Â¿Â½s being used. The requirement for Ã¯Â¿Â½high frequency control gearÃ¯Â¿Â½ in fluorescent luminaires is a worthy statement, but it does not go far enough. All that the HF control gear requirement does is to ensure that you get a more energy-efficient lamp and gear arrangement, rather than the pre-historic switch-start, wound-ballast, version. But it says nothing about luminaire performance, which is where our attention should be aimed, because if itÃ¯Â¿Â½s a poor luminaire, then the inclusion of efficient control gear does nothing to help.
A few words here about how we need to change the way that we assess project costs. The old cost comparison model is based on the Ã¯Â¿Â½blanket designÃ¯Â¿Â½ approach; we light an entire room to a particular illuminance for a particular period of time Ã¯Â¿Â½ usually the whole working day. That only requires a simple bit of mathematics to translate the physical situation into a projected kWh cost. Payback periods for better (more expensive) technology could be worked against that model, but now that weÃ¯Â¿Â½re contemplating a high energy cost future in a low-carbon environment that model no longer serves.
We need to squeeze the last drop out of the Ã¯Â¿Â½lamp+control-gear+luminaireÃ¯Â¿Â½ hardware, and that means we must ensure that weÃ¯Â¿Â½re utilizing the best that product design has to offer, and thereÃ¯Â¿Â½s a cost associated with that. But we also want to reduce the length of time that we use the hardware, and even have the facility to reduce the luminaire's output when required. That means we spend more money on our luminaire and our control arrangements and we only begin to see the savings that weÃ¯Â¿Â½re making when a proper Life Cycle Assessment is made of the installation. Arguing the low-unit-cost against the efficient-high-tech model no longer works for us, and itÃ¯Â¿Â½s going to be a bit of an adventure seeking out a new model that does work.
Greenwashing: a guidline for good behaviour
The elephant box in the room
What Lighting Designers Should be Looking For . . . and Asking For
The Children's Fire
Products That Last - Redux
Products That Last - Review No.3
Products That Last - Review No.2
Products That Last - Review No.1
Products That Last
Talking about Waste - as we were . . .
Sustainability - They Seek it Here, They Seek it There . . .
Sustainability - the core message
The Life and Times of the LED - a series in ten parts
Sustainability: They Seek it Here; They Seek it There . . .
John Bullock writes a regular column for lighting magazines. You can find all of the archived pieces here.
BLOGS - LIGHTING DESIGN
John Bullock writes about all things and anything concerning architectural lighting design; new technologies and old lamps; anything,really.
HOME LIGHTING CONSULTANT
John Bullock designs innovative lighting designs for people's homes. By working closely with clients he is able to deliver solutions that meet - and exceed - their expectations.
BLOGS - CPD RIBA CORE PROGRAMME 2015
John Bullock will be presenting a seminar on latest lighting design and technologies as part of the RIBA CPD Core programme 2015
BLOGS - SUSTAINABILITY
John Bullock believes that the UK lighting industry needs to embrace a sustainable way of delivering good quality product through good design, fabrication and end-of-life management.
BLOGS - LIGHTING HEALTH AND WELLBEING
Lighting has a vital role to play in our health and wellbeing.
CONDUIT (6) - Lighting for Winter Gardens
CONDUIT 5: Home Lighting - LED Lighting (2)
FX Magazine: Lighting Focus - Sustainability (Issue 258)
CONDUIT 4: Home Lighting - LED Lighting (1)
Can Smart Lighting Save The Planet?
CONDUIT 3: Home Lighting - The Bathroom
Can Lighting Save Us From Ourselves . . . NO!
CONDUIT 2: Home Lighting - The Dining Room