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Depending on the climate, that you live in, heating your home in an emergency may be a matter of life or death. Where I live it would be cold, but with dressing warmly, I could survive in my home without any additional heating. Now I am not saying it would be comfortable but I could get by well with this improvised heater.
Now I know that many of you who live in ultra cold climates have multiple means of backup heat, wood stove, coal, propane and etcetera. But what about these you who live in climates where a bit of heat would be nice but is not necessary or if you have to bug out and leave your preps. Can you make an improvised heater that will heat a small space or a tent?
I have been playing with a heater that will take the chill of a small room and even in a cold climate combined with other techniques could keep you alive. See Staying Warm While Sheltering in Place After a Disaster for some other ideas.
In the heater I built, I use two different size clay pots, a bread pan, 4 tea light candles, a bolt and a washer. These are items that normally are not to hard to find. Any small homemade oil lamp or candle could be substituted for the tea lights. They would just have to be small enough to fit.
I set the four tea light candles in the bread pan and lit them. You then place the smaller of the two clay pots on top of the bread pan. Use the washer and bolt to plug the hole in the bottom of the clay pot. Then place the larger pot over the top of the smaller. The heat from the candles will heat the inside pot and convection will transfer the heat to the larger.
I have been running one in my office for about 2 ½ hours now and it looks like the tea lights are starting to get low The pan is too hot to touch and I can just lay my hands on the outer pot. I would not try to touch the inner one. This little heater is putting out quite a bit of heat and has driven my wife out of the room.
Using a tuna or an Altoids can, some oil and a cotton wick, you could make one that would run considerably longer. It may not keep you warm and toasty, but it might keep you alive. Don’t forget to leave a small amount of ventilation the improvised heaters will give out carbon monoxide.
Howard
A British Thermal Unit or BTU is the amount of heat energy required to raise the temperature of 1 pound of water 1°Farenheit. A modern candle is made of wax made from petrochemicals. The lighted wick melts the wax, which evaporates and ignites. As wax vapors rise, they stay longer in the hot regions of the flame and burn completely aided by ambient oxygen in the air.
A candle flame has three regions: The inner wax vapor zone appears dark black and is the least hot region of the candle flame. The mid zone of the flame appears yellow because sufficient oxygen is available to ignite, but not for the wax vapors to burn completely. This luminous region of the candle is not very hot. The outer zone where the wax vapors have sufficient oxygen from ambient air to burn completely appears blue and is the hottest part of the candle flame:
Wax calorific value = 8.4 kJ/g
1 joule = 0.0009478134 btu
To determine how many BTUs are generated by burning a wax candle, multiply its weight in grams times 8400 and then multiply by 0.0009478134. One ounce = 28 grams.
If you would like the heat value in watts, after 2 minutes of Google searching I found candle heat output values ranging from 40-100 watts, so a good average is 70 watts. Multiply by 3.412 to get BTU’s.
If you prefer caloiries, there are 252 calories in a btu, so it takes 252 calories to raise the temperature of one pound of water at or around its boiling point one degree F in one hour 252 x 60= 15,120 or 15,120 calories per hour x 24 hours = 362,880 calories for a ton of refrigeration, i.e. it takes 362,880 calories to melt a ton of ice.
Please explain to me why this device would heat the room any more that just burning the candles alone without the pot.
Hangtown Frank
The clay pot hold the heat. They get surprisingly hot. Just remember if you try this the smaller the space the better it works.
Frank,
Think of the heat as a stream of water coming off the candle; uninterrupted it will rise until it reaches the roof and spread out. It also diffuses as it rises — but very slowly and very little (convection).
The pot on the other hand acts as a shield to redirect the heat outward from the candle — at much lower heights. It turns the candle into a radiant heater.
Thanks Bob that is a better explanation than mine.
Howard
One question, one comment.
Why did you put one pot over the other? Safety measure? Extra radiant mass? Both? Other?
Instead of the tea lights, I have taken one of those round Christmas cookie tins with the tight fitting lid, cut cardboard strips the same width as the depth of the tin, and wound the strips inside the tin like the grooves on a record album. Then I saturated the cardboard wick with anti-bacterial hand cleaner. This burns like sterno. I placed this on a nan-flammable surface. I put some metal pieces I had around under the lip of a large flower pot to allow airflow. The amount of heat from this was unbelievable. More spacers on top of the flower pot to hold a pan from direct contact and you will get enough heat from the flower pot’s drain hole to boil water. I didn’t try cooking anything else.
Could you please show us how to do this? In pictures? I think both are wonderful ideas! I live in Alaska and could use all the ideas possible to help keep my family alive in winter. Thank you so very much, Megan
HAPPY THANKSGIVING!!
Megan
I will make a video of how to do this and post it in a few days.
Howard
Today I experimented with this. I took a large, heavy, clear glass plant vase (like the ones roses or other long stem flowers are delivered in) which is 10″ tall. I placed an 8″ pillar candle in the vase. I placed hardware cloth (which isn’t cloth at all it is heavy duty wire mesh) over the top of the vase and then placed an inverted clay pot over the vase. I was careful to leave space around the top of the vase so air could flow freely to the candle. I then placed a clay saucer inverted on top of the clay pot.
I am very pleased with the heat and light this produces.