Save energy: light a candle under a flower pot to keep warm

Here's a very simple and very cheap way to warm a room:



Candle Powered Air Heater - DIY Radiant Space Heater - flower pot heater - Easy DIY - YouTube

With over four million hits on YouTube, this has really proved popular - as testified in a Daily Mail piece this time last year:
Could this be the answer to rising energy bills? Home made flower pot heater cost just 8p a day to run. | This is Money

Here's a look at the science and the figures:
Flower Pot Heater - The reality - YouTube

Plus a Brit's adaptation:
CLAY POT with TEA LIGHTS Room Heating | 4HR DIY Test - YouTube
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