What Part of The Flame is the Hottest

So, what part of the flame is the hottest you ask?

It might sound like your mind is working overtime if you are thinking about this question.

But STOP!

It is a very good question.

Don’t you want to know how the world works?

So… What Part of The Flame is the Hottest Then?

Some people might think that the top of the flame is the hottest. But you would be mistaken…

The hottest part of the flame is actually the base.

There… I have answered your question.

But wait!

I can not stop here or else this would not be an article, would it?

I think there is some explaining to do, don’t you think?

So, overall, this typically burns with a different colour to the outer edges or the rest of the body of the flame.

Blue flames are the hottest, I know that you would think red.

Red depicts this in our minds, but no. The colour blue which we would usually regard as cold is not when it comes to flame.

See…

The plot thickens.

Arnt, are you glad that I carried on reading?

Then we are followed by white.

Still not red yet.

After that, comes yellow, then orange and finally red are the common colours you will see in most fires.

Now I am saying most are, as rules were sometimes meant to be broken.

A flame that has its fuel mixed with air before burning and a relatively steady shape of course.

This is an interesting fact… Although a candle flame appears to be a solid mass of light, it is not as solid as you would think.

It is just an illusion, as it is actually hollow, you see…

The luminous outer layer of the flame is typically less than 1 mm thick.

Now the core of the flame consists of the fuel gas and air which is pushing steadily outwards in the flame shape itself until they reach the thin combustion zone.

The hottest part of the flame is actually in and outside this flame zone.

Here it is filled with the immediate products and also the partial products of the chemical reaction known as we all do…

The combustion.

So, the hottest part of a flame is the blue part.

‘The proof is really in the pudding’ as they say… When it comes to the temperature you are looking at a good 1670 degrees F (1400 C.)

This is where the flame is getting the most oxygen, and therefore the most fuel for the fire to reach its highest temperature.

What are the Colors of a Fire & How Hot are They?

When you think of a typically controlled fire, such as a bong fire or campfire for instance…

Hot, to a roaring, or roasting hot.

Or you might think of shimmering, dancing, to sparkling.

Just as colours appear in a variety of many hues and intensities.

This makes sense since fire is really just a hot light.

Or is it?

The colours that you do see in fire do correlate with the certain temperature in the fire as well.

So the different colours depict more often than not in the hotter flames and others when things are just getting going or dying out.

But the situation is more complicated than it appears…

Depending on what is burning in a given fire, also influences what you will see in the colours in the flaming mix.

How are These Visible Colors Produced?

What part of the flame is the hottest is one thing, but the other question I want to talk about is whether what you see as light is the actual colour of fire.

Now…

I have one word for you here, and that is Electromagnetic Radiation (EM).

Ok…

That’s two.

Electromagnetic Radiation, being visible light is one of a number of types of EM and occupies only a small fraction of the entire EM spectrum.

These EM waves are actually characterized by a wavelength.

That’s right.

Colour is wavelengths.

The distance between corresponding points along with a graphed EM wave, and also a frequency, being, the number of wavelengths per second passing a fixed point.

Now we are getting more complicated here…

• The product of wavelength (λ) and frequency (ν) of an EM wave is always the speed of light c (3× 10⁸ m/s) no matter the EM wave type.

The range of wavelengths that are below about 440 nanometers ( 4.4 × 10⁷ m) includes radio waves at the low end, then microwaves.

Now, if we go above that. Say… At about 7 × 10⁷ m, X-rays and gamma rays appear; these have high frequencies and are associated with higher energy as a result.

And this in turn has implications for the colours that we see glowing in the flames.

The visible light spectrum itself is (4.4 × 10⁷ to 7 × 10⁷ m) and includes radiation perceived by the human eye as, in order:

• red
• orange
• yellow
• green
• blue
• indigo
• violet

Are Temperature and Flame Color Directly Related?

As you have learned, both the type of material being burned in a fire and the temperature of a fire influence the colours you see produced.

Also, as the example of the two vastly different candle temperatures illustrates, anyone fire is almost certain to have a range of temperatures within it (explaining a large amount of the colour variation sometimes observed).

When something is heated, it first turns to gas.

These gas molecules then react with the oxygen if they are in fact combustible molecules.

It would be typical to see a fire consisting of uniform material and heated in a controlled way show:

• reddish
• orange
• finally, bright yellow flames

Which is demonstrating increasing energy and heat that is released.

If you closely study a candle when you light it, you will probably see that a sizable portion of the outer core of the flame is blue in colour.

You will find that this is not normally seen much in fireplaces.

It all depends on the heat of the fire really.

The Flame Color Temperature Chart

While sources do vary somewhat from one source to another…

It is possible from all this to construct a fairly reliable enough chart showing the relationship between flame temperature and flame colour across the visible light spectrum.

So here it is:

• Dark red (first visible glow): 500 to 600 °C (900 to 1,100°F)
• Dull red: 600 to 800 °C (1,100 to 1,650°F)
• Bright cherry red: 800 to 1,000 °C (1,650 to 1,800°F)
• Orange: 1,000 to 1,200 °C (1,800 to 2,100°F)
• Bright yellow: 1,200 to 1,400 °C (2,100 to 2,500°F)
• White: 1,400 to 1,600 °C (2,500 to 2,900°F)

Those temperatures that are high enough to produce those blue flames are unusual when it comes to campfires.

This is why they are more often seen when it comes to man-made flames.

So, we went from what part of the flame is the hottest to flame colours.

I hope that you got something out of this and realize that fire is very fascinating. And it just does not conjure itself up out of anything.

In fact, everything needs some starting point to become something else…

So when someone asks the question what part of the flame is the hottest? you have something to tell them.