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.

  • @recklessengagement
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    6 days ago

    I used this trick a few years back during a cold snap when my furnace wasnt working. It did genuinely seem to increase the temp of my room by around ~10 Fahrenheit over an hour or so.

    my understanding was capturing the hot air for a moment allowed more heat to radiate (and the pot did genuinely get to around 150 degrees according to laser thermometer) instead of the hot air rising in a narrow stream and losing its heat into the cold ceiling.

    Didn’t have a fancy setup, just a spare pot balanced on three mugs over some tea candles.