Lighten up!
From Sanctuary issue 10. More articles like this
By Michael Green
Excerpt: The days of old-fashioned incandescent light are numbered. Incandescents work by heating an electrical element to white hot, and as light sources they make great heaters! They’re cheap to buy, but expensive to run. And being very inefficient, they come at a huge cost to the environment. So much so that in February 2007 the Australian government announced it would phase out standard incandescent light globes.
Since November 2008, Australian shops have only been allowed to sell their preexisting stock. Not included in the first stage of the phaseout, however, is the common halogen downlight – though the writing is on the wall for these too. Halogen manufacturers are working hard to improve the efficiency of their lamps, but it seems likely that these too could succumb to regulation – as well as be outcompeted by a host of rapidly developing, high-efficiency counterparts. The downsides of halogen downlights are so numerous one can only wonder how they became so ubiquitous. They use a huge amount of electricity, producing a lot of heat in the process. Because downlight fittings and their transformers must be able to cool themselves, they can’t be covered by roof insulation, so they reduce the effectiveness of the roof insulation. They are also a notorious fire hazard: in the first nine months of 2009 in New South Wales there were 26 house fires attributed to halogen downlights.
When it comes to low-energy lighting technology, there are two main kinds to choose from: fluorescent lamps – both old-style tubes and newer compact fluoros (CFLs) – and light emitting diodes (LEDs). David Baggs, technical director of Ecospecifier, an eco product database (www.ecospecifier.org), says that when choosing lights it’s wise to remember both colour and brightness. Most people prefer the yellowish glow given off by incandescent globes. “To get a light that has the warmth we’re comfortable with, ask for ‘warm white’ CFLs or LEDs,” Baggs says. Halogen downlights are also very bad at one of the main things they’re asked to do: light whole rooms. Halogens are task illuminators: they create bright pools of light rather than general illumination; hence designers misdeploy row upon row of halogen downlights to light a single room – sometimes 12 or more – where one or two pendant lamps would have done the job. Most rooms require two types of lighting. General lighting gives all-over illumination. Task lighting is for specific areas, such as desks or work benches. If you know what kind of lighting you require for a particular situation – general or task – you are halfway to efficient lighting. The other half of the equation lies in choosing the right lighting product for your general and task lighting needs.
