There has been a rash of video’s and facebook posts promising to “Easily Heat Your Home Using Flower Pots & Tea Lights”. This is an older concept that seems to be dusted off every once in a while, and pushed on the gullible. I will attempt to explain the science behind the phenomena, and you can decide if it works for you.
A naked candle puts out a very small amount of heat into a room (approximately 263 BTU/h or 77w), so you would need 19 candles burning to equal the typical 1500w room heater.
Ok but a flower pot makes it put out more heat, right?
No, a flower pot converts the candles convective (air) heat, to radiant (body) heat. It also shifts the time period, as the clay takes a while to heat up, and also to cool down. If you are sitting directly next to the pot, you would feel warmer, but the room would take longer to heat up. Both methods would bring the room up to the same temperature.
19 candles would incur sooting and corresponding lung issues, so I suggest a cleaner heating source. For comparison purposes, a 77 watt light bulb running 24 hours per day costs $0.18 (at $0.10 / kWh). That’s cheaper than buying candles, and better for your health. You could put it in a flower pot if it makes you feel better ….