How energy efficient are halogen lightbulbs?

Question

We have started replacing the incandescent light bulbs in our house with the more energy efficient 'compact fluorescent' bulbs. However, we have halogen downlighters (flush ceiling mounted) in three rooms. How energy efficient are these? One room has 6 x 35W AC GU10 type bulbs, the other two use several of the DC bulbs that feed off a transformer. Do these use a lot of energy? Should we look at replacing these too?

Answer 1

You should replace the halogen bulbs if energy efficiency is your objective.

Answer 2

Hallogens in general are not energy efficient.  They are more effective as a heat lamp than as an illuminating lamp.

The energy spectrum of a hallogen illuminates heavily to the red/IR side, which means a lot of energy output is infrared (heat) and is not even visible.  Sure they may be bright, but if you compare how well they illuminate compared to compact flourescents, they are out-lit BIG-time when you compare their power consumptions.  You can get a 20W compact flourescent bulb that can illiminate pretty brightly (compares to a 100+W incandescent)  So if you had three 20W compacts, they would have the same light output as a 300W torche.

However, I am familiar w/ those in-line DC lights.  The only advantage those little things provide are their compact size.  You are compromising of wasting electricity to illiminate a tight space or illiminate in a discrete way.