candle powered heater

OK, I saw this on Facebook and searched You Tube for opinions. http://youtu.be/eyRzcwGbvwE
I have been using this or about a month now and it has been working.
They are as stated only a radiant heat.  I wanted to laugh at the guy who thought it would keep his greenhouse warm.  Really???
I found that if I add oil to the candles they burn longer.

 Best thing is the cats have not messed with it.

here is how I have mine set up.

I have the candles and oil in a terracotta saucer on a low stand. (before when it was on the ground it glued itself to the tile floor.)
on the saucer I have rods/dowels/sticks whatever you want to call them to create an air flow space for the candles to get oxygen. there was some trial and error to find the right size.
set the smaller pot over the candles with something to block the water hole in the pot. I am using a flat rock I found.  over this is the second pot.

and on this i set a small tea pot.  two functions warm tea and humidity.

I have found that if I soak the outer pot in a  pot o water it will produce humidity through the night.