Short example of radiative heating from today's lunch. We were at a Japanese restaurant and they did the usual bit of cleaning the surface and then spraying it down with something flammable and igniting it. We noticed that we felt the heat even from the burners 20-30 feet away as the big whoosh of flame went up.
I've mentioned before that there are three methods of moving heat around -- conduction (molecules bouncing in to each other; very slow), convection (carrying the hot air from one place to another, and radiation. Now hot air rises, and we were not sitting above the burners! So what is left is radiation. The short-lived, but hot, sheet of flame radiated some heat over to us 20-30 feet away.
Some fireplaces take advantage of the principle by using a 'firebrick' which absorbs heat and then efficiently radiates it back in to the room, rather than letting it go with the air up the chimney..
Anyone else have a daily experience with (non-solar) heat transfer by radiation?
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