Candle Powered Heater DIY Space Heater. Clay/Terracotta pots absorb the thermal energy of the candles and convert it into radiant space heat. Reaches temperatures of 160F to 180F.
Heater stays hot for hours. use caution, the inner chamber can reach 500F. heats a small area very effectively. uses 1 to 3 candles or more. could also use small alcohol lamps instead of the candles. of note: heater works by trapping and concentrating the heat that would normally just rise to the ceiling and quickly dissipate in the surrounding air. once pots have warmed up they stay hot for hours.
I built both 2 and 3 pot heaters. the 2 pot heater seems much more effective (if you are using large thick pots). if the pots are smaller then 3 pots may be better.