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Q & A: silver kettles

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Most recent answer: 07/06/2008
Q:
We were shopping for a new kettle and I discovered that they were almost always silver or white. I think its something to do with helping the water heat but I couldn't think why - please tell me.
- Kayleigh
Doncaster
A:
Just as a silvery kettle reflects light which hits it from the outside, it also reflects light from inside back. That means that it won't radiate infrared light much when it gets hot. That then means that less energy is needed to get it hot. A weakly-reflective dark surface (say cast-iron) absorbs and transmits light much better, so to heat it you'd have to supply more energy. The infrared radiation from it would just heat up the room, a particularly unpleasant result in the summer.

Mike W.

(published on 07/06/2008)

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