Making a tealight/teracotta pot heater more efficient
December 14, 2013 8:44 AM Subscribe
I've gotten caught up in the hype about those upturned-terracotta-plant-pot-with-tealight-candles-underneath-heaters, so I've made one. It's doing the job and keeping the chill off, and what can I expect, really, from something heated by 4 tealights. I want to make it more efficient, though.
posted by Solomon to Science & Nature (11 answers total) 8 users marked this as a favorite
The design I'm using at the moment is a 19cm X 9cm X 5cm loaf tin, inside which are 4 tealight candles, in the middle. Placed over the top of the 4 tealights is a 13cm X 13cm unglazed terracotta pot. The hole in the pot is stoppered up with some aluminium foil with a pebble from the garden on top. When the candles are lit, heat can be felt from the unit up to about 30cm away.
What variables is it worth me changing to get more heat out of the unit, or at least feel more of the heat that is currently being radiated?
Things I've thought of so far:-
More candles: more heat in = more heat out, I figure. This will mean using a larger pot, though, with a larger surface area - worth it?
Add more pots inside the existing pot: I've seen this done online, with steel bolts and such, but doesn't this just increase the amount of heat that gets absorbed and cause less heat to be radiated?
Some kind of shield to reflect heat back from the other side of the unit: what would work to do this?
Suspend the pot in the air: at the moment the pot is resting on the metal loaf tin, which gets quite warm - would contriving something to hold the pot in the air help with this?
Paint the pot black: I think this only helps with heat absorption, not radiation?
There's a device called a "kandle heeter" that is a very similar sort of device. The website isn't really that encouraging though...
Any thoughts or ideas?