I'm baffled by this whole Crisco/shortening candle-in-contraptions meme circulating around. You've got folks shoving these things in everything from copper pots to elaborate sand enclosures, claiming superior heat output and somehow making a case for off-grid energy.
Let's unpack the physics, because frankly, it doesn't add up:
Combustion 101: A candle (or our Crisco-fied iteration) works by burning the fuel source (fat in this case), releasing heat and light through a chemical reaction with oxygen. The material surrounding it doesn't inherently influence this combustion process. Copper, terracotta, or sand won't magically accelerate the burning rate or somehow trap more heat.
Radiation & Conduction: Sure, these materials might hold and radiate a BIT more heat absorbed from the flame compared to open air. But the difference is negligible. Convection (hot air rising) is the primary heat transfer mechanism, and the enclosure doesn't significantly enhance it.
Scaling Up Fallacy: If this contraption truly held the key to efficient off-grid heating, wouldn't we be ditching fuel oil and natural gas entirely? Imagine a skyscraper-sized Crisco candle in a cosmic copper pot - it wouldn't magically solve our energy needs. The heat output wouldn't scale proportionally due to limitations in combustion itself.
In short -- why are people so fascinated with this? A simple test will show that it is not more effective than a simple candle, yet people seem to be continually fascinated by it.
If you heat the room with a candle, you probably won't notice the difference. Most of the heat will likely rise to the ceiling leaving you still mostly pretty cold, even if the room is 52.4 degrees rather than 52.2. Trying to directly warm yourself with a candle doesn't really work either; the "habitable zone" of a bonfire is pretty big, you can be several feet from the flames and feel comfortably warm. A candle is so small that the distance between "can't feel any heat at all" and "first degree burn" is thinner than your hand.
Putting a terra cotta pot over it will warm the pot to the point it feels warm, it lets you meaningfully experience the heat of the candle. That same energy will be spread out on a large surface which will feel comfortably warm to the touch.
I saw people start to come up with these contraptions after those Texas deep freezes where an entire state was caught so thoroughly off guard by long sleeve weather that they started teaching each other how to shit in buckets.
If a Youtube video gains any attention, the idea cancer will soon follow. "Hey you might be able to improvise an emergency heater out of these things you probably have around the house" becomes "finger family pregnant frozen spiderman builds artisanal crisco emergency heater."