What to do if you have a house full of halogen downlights
Halogen downlights have become one of the most fashionable lighting trends in recent years, but here are a few things the marketing crowd won't tell you:
- Low voltage doesn't mean low energy use - watts are the measurement to look out for.
Standard halogen globes use 50 watts each, plus each globe is wired to a transformer in the ceiling space. Transformers use about 10W each. So, each downlight generally uses about 60 watts. When you pair this with the fact that you need about six downlights to achieve the same light output as you get from one standard incandescent or compact fluorescent lamp, you can see the energy use starting to add up.
To put it simply: 6 x 50W halogen downlights + 10W transformer = 360W!
By comparison: 1 x 13W compact fluorescent lamp = 13W!
Halogen globes put out a lot of heat - in fact, like incandescent globes, they're more accurately described as mini-heaters rather than lights! This means that on a hot day, halogen downlights will increase the temperature of your rooms and add to the strain on your air conditioner, if you have one.
Unfortunately, they don't perform any better on cold days - because downlight fittings are recessed into the ceiling space and heat up to high temperatures, insulation must be kept clear of the fittings. This means that wherever downlights are installed, the insulation in the ceiling is full of holes - as mentioned previously, a 5% loss of insulation can reduce the effectiveness of the total insulation by half!
Recessed downlights also often create draughts through gaps in the fitting - this leads to the "thermal chimney" effect, where warm air rises up to the ceiling and disappears through the gaps.
WHAT TO DO:
So, you have a ceiling full of recessed downlights and have noticed the hike in your bills; don't despair, there are things you can do!
Leave the downlights switched off as much as possible and use a floor lamp with a compact fluorescent instead.
30 and 35W replacement halogen globes are available at all good hardware stores, and use reflectors to make sure they put out just as much light as 50W globes.
There is a range of products coming onto the market that have the look of downlights but not the high energy use. One of these is the Megaman compact fluorescent downlight - the fitting looks like a "normal" downlight but uses a compact fluorescent lamp instead of a halogen globe. These don't run on low voltage so you will need an electrician to change the wiring for you when you first install them.
Another low energy use replacement product is the Hotbeam LED downlight, called DownLux. This product has just become available commercially - check it out on the Hotbeam website at www.hotbeam.com.au.
Or there's also the Lamp Luxeon 12V 3W Led White. See lighting article for further details.
For further information about these products visit:
The Environment Shop: http://www.environmentshop.com.au/display.asp?ID=9
Going Solar: http://www.goingsolar.com.au/php/cat_lighting.php
