Don’t fall for the Tealight-Flowerpot Heater
Temperatures are plummeting in different parts of the country and world, and your heating budget may be limited by higher fuel or electricity prices. Videos of heating rooms with a simple tealight and claypot have gone viral since about 2018, and these seem too good, easy and cheap to be true, well, they are.
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First of all, the danger of starting an uncontrolled fire in your home is real. Many of these setups are “balanced” on the tealights themselves or other materials that can be knocked over easily. Also, tealights are made from paraffin, which are a purified hydrocarbon material. Aside from adding these hydrocarbons to the air you’re breathing, here’s the scary part: they can ignite spontaneously when they get really hot. We know that paraffin liquifies (melts), but did you know that the liquid paraffin can also self-ignite at a flash point of 400°F (204°C)? You won’t get this kind of heat with one tealight, but many videos suggest grouping four of them under a clay pot. This many tealights together will produce enough heat to warm the pot above the flash point. The hot pot ignites the paraffin vapors under it, and you have a fireball that can cause the clay pot to shatter and send flaming liquid wax all over you and the room. Firefighters warn against using homemade heaters like this because of the devastating fires they’ve caused. (Firefighters issue safety warning over viral social media trend after flat fire in Derby)
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Secondly, tea lights don’t put out that much heat. A single candle produces anywhere from 75 to 85 BTU, which we’ll average to 80. To heat a small 10x10 foot room (100 square feet), would require 4,500 BTUs to be heated effectively, which would take over 56 candles. (Can a flower pot and tealight candle create enough heat to save you in a cold emergency?) At this point, you would probably need to open a window to bring in fresh air for burning and vent the combustion gasses given off by this many candles, effectively allowing your heat to go out the window!
Placing a clay pot over the candles concentrates the heat, but it doesn't change how much energy the candles release. It’s like placing a powder drink mix into 2 gallons of water vs. 16 ounces of water. If you drink the 2 gallons of water and your friend drinks the 16 ounces, you will still only take in 1 packet of powder each. Your friend will be more satisfied with the 16 ounces because it will taste better, because it’s concentrated. Similarly, you will feel more satisfied putting your hand near the clay pot, but with or without the pot, the tealights are still emitting the same amount of heat.
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It’s actually more expensive than you think. According to this article, a single tea light produces about 35 watts of heat. Even burning continuously, candles deliver heat at a far higher cost per kilowatt hour than electricity—and many times more than gas.
So are these DIY heaters useful at all? Yes, in a survival situation, they could help keep you warm. If you are trying to make it through a true emergency cold snap, the trick to using them is to downsize the “room”; instead of trying to heat a whole room, place a tarp over yourself and the heater to contain the heat (similar to making a “fort” like kids do). Make sure the tarp is secured to avoid falling/getting near the heater, and make sure you don’t actually touch the heater or knock it over! Because an open-flame heater sitting on the floor or other objects is so dangerous, it would be dangerous to use in a tent.
Photo by Zoran Kokanovic on Unsplash
