Lighting constitutes a significant proportion of a home's total energy consumption. Our architects recommended we engage
DPA Lighting to design a low-energy lighting plan. So, we worked with DPA's Tanya Aitken who has many years experience with low energy lighting.
For aesthetic and practical reasons we opted for downlights throughout the interior of our home. Tanya recommended that we use 12 volt halogen lights in rooms that were under the concrete slab and ultra-compact fluorescent lights (UCFL) in spaces that have a roof cavity above them.
Each halogen light consumes 35 watts plus an overhead for each voltage transformer. We opted to use good quality, high efficiency transformers. UCFLs consume a meagre 11 watts per light and don't need a transformer.
You might ask why we didn't use UCFLs throughout the house given their significantly higher efficiency. Tanya cautioned us that UCFLs are dimmer and take a couple of minutes to warm up to full brightness. If we found that we disliked this then it would be very expensive if not impossible to rewire the fittings under the slab but less of an issue for fittings with roof space above them.
Tanya was right. The UCFLs are quite dim when first switched on and in our bedrooms and bathroom this would have been quite annoying.
LED downlights were prohibitively expensive at the time but we have used five LED lights as step lights in the stair well. These consume a miserly few watts per light.
Exterior lights are mostly high power halogens but as they're used infrequently we were more interested in strong illumination rather than energy consumption. On the balcony and
al fresco UCFLs are installed.
For cost savings we have compact fluorescent or standard fluorescent fittings in the garage, walk-in robes, pantry and under-stairs store room.
Recently, one of the UCFL lamps expired well short of its 15,000 hour supposed lifetime. The cost of LED lamps has dropped precipitously in recent times so I replaced it with an LED lamp. I was pleasantly surprised. The LED lamp had similar brightness, lower energy consumption (3W), instant full brightness and no mercury.
As the UCFLs expire I'll replace them with compatible LED lamps.
UCFL downlight (11W, 240V)
Halogen downlight (35W, 12V)
LED downlight (3W, 240V)
LED step light
