No, frozen candles do not burn slower
www.madsci.org
Fats and oils are
chemically the same sort of thing ("triglycerides"). The difference is the melting point: Fats
are solid and oils are liquid at room temperature. You can fry with lard (a
fat) or with canola oil (an oil) but when you're frying, the fat/oil is a
liquid! And when you burn a fat or an oil, it's the liquefied fat or oil
that is burned.
In fact, things burn best when vaporized. Substances that don't vaporize
easily, like coal, are not as easy to burn as substances that can vaporize
at the temperature of their own flames.
In order to help the vaporization process along, the liquid oil or melted
fat is drawn up into a cloth wick (by capillary action) and vaporized by the heat of the flame; the
burning takes place just above the wick. A thin layer of the liquid is
present at the wick's surface. Because the liquid layer prevents oxygen
from getting to the cloth, the wick doesn't burn up, but the heat of the
flame does convert it to more-or-less pure carbon ("char").
In the same way, paraffins are hydrocarbons (like kerosene or gasoline)
except that they are solids at room temperature. When you burn a paraffin
or kerosene or gasoline, it's always the gas phase that burns--that's why
natural gas is such an efficient fuel: It's already a gas! Part of the heat
of the candle flame goes into vaporizing the paraffin so it can burn. In
the engine in your car, a lot of ingenuity goes into reducing the liquid
fuel to a fine mist of droplets that evaporate more easily in the
cylinders; this increases the amount of heat that can be used to actually
run your car.
What this means is that
www.madsci.org
Fats and oils are
chemically the same sort of thing ("triglycerides"). The difference is the melting point: Fats
are solid and oils are liquid at room temperature. You can fry with lard (a
fat) or with canola oil (an oil) but when you're frying, the fat/oil is a
liquid! And when you burn a fat or an oil, it's the liquefied fat or oil
that is burned.
In fact, things burn best when vaporized. Substances that don't vaporize
easily, like coal, are not as easy to burn as substances that can vaporize
at the temperature of their own flames.
In order to help the vaporization process along, the liquid oil or melted
fat is drawn up into a cloth wick (by capillary action) and vaporized by the heat of the flame; the
burning takes place just above the wick. A thin layer of the liquid is
present at the wick's surface. Because the liquid layer prevents oxygen
from getting to the cloth, the wick doesn't burn up, but the heat of the
flame does convert it to more-or-less pure carbon ("char").
In the same way, paraffins are hydrocarbons (like kerosene or gasoline)
except that they are solids at room temperature. When you burn a paraffin
or kerosene or gasoline, it's always the gas phase that burns--that's why
natural gas is such an efficient fuel: It's already a gas! Part of the heat
of the candle flame goes into vaporizing the paraffin so it can burn. In
the engine in your car, a lot of ingenuity goes into reducing the liquid
fuel to a fine mist of droplets that evaporate more easily in the
cylinders; this increases the amount of heat that can be used to actually
run your car.
What this means is that
- The wax in a candle has to be melted and evaporated before it
can burn, and the difference between the temperature of your freezer and
the temperature of your living room is much smaller than the additional
rise in temperature required to melt and evaporate the candle wax.
- Candles just out of the freezer will have a harder time
starting, partly because the wax at the top has to be heated that extra
50-60° F. (The main reason, though, is probably that when you take
candles out of the freezer they acquire a film of frost from the moisture
in the air, and that has to be evaporated before the candle can burn.)
- As you discovered, there is therefore no difference in the rate
of burning of a frozen candle and one that's been stored at room
temperature. About the only thing freezing will do for you is make the
candle more brittle, so that it is more likely to break in storage but less
likely to deform or bend.
