Why does moving air feel cold?

[Eli]

Originally posted by: HardcoreRobot
in a related note, if you are trying to cool yourself off by blowing air on yourself, make your mouth as narrow as possible. forcing the air through a smaller hole takes the heat out of the air. you can try it on your hand, if your mouth is open wide it is hot and sticky

also, i love this quote "friction causes the cold" hahahahahahahaha

Compression causes heat; squeezing air through a smaller hole would not cause it to lose heat.

It would increase the pressure though, possibly causing the illusion it is cooler, due to things already mentioned in this thread.

 

[LongCoolMother]

Originally posted by: HardcoreRobot
in a related note, if you are trying to cool yourself off by blowing air on yourself, make your mouth as narrow as possible. forcing the air through a smaller hole takes the heat out of the air. you can try it on your hand, if your mouth is open wide it is hot and sticky

also, i love this quote "friction causes the cold" hahahahahahahaha

rub your hands together. it should get freezing cold!!

 

[HardcoreRobot]

Originally posted by: Eli

Originally posted by: HardcoreRobot
in a related note, if you are trying to cool yourself off by blowing air on yourself, make your mouth as narrow as possible. forcing the air through a smaller hole takes the heat out of the air. you can try it on your hand, if your mouth is open wide it is hot and sticky

also, i love this quote "friction causes the cold" hahahahahahahaha

Compression causes heat; squeezing air through a smaller hole would not cause it to lose heat.

It would increase the pressure though, possibly causing the illusion it is cooler, due to things already mentioned in this thread.

not an illusion, the air is colder

 

[igowerf]

How come every time someone asks a question like this, twenty people chime in with differing yet very confident answers?

 

[LongCoolMother]

Originally posted by: igowerf
How come every time someone asks a question like this, twenty people chime in with differing yet very confident answers?

i think most of us agreed. except for the statement about the friction .

 

[nakedfrog]

The wind has a name in the desert (Scirrocco)
But it's rarely known

 

[biostud]

Try to hold your arm into fast moving hot steam, then you will notice it does not feel cold.

 

[Indolent]

in more technical terms,

it increases the convection coefficient between your skin and the air.

 

[Eli]

Originally posted by: HardcoreRobot

Originally posted by: Eli

Originally posted by: HardcoreRobot
in a related note, if you are trying to cool yourself off by blowing air on yourself, make your mouth as narrow as possible. forcing the air through a smaller hole takes the heat out of the air. you can try it on your hand, if your mouth is open wide it is hot and sticky

also, i love this quote "friction causes the cold" hahahahahahahaha

Compression causes heat; squeezing air through a smaller hole would not cause it to lose heat.

It would increase the pressure though, possibly causing the illusion it is cooler, due to things already mentioned in this thread.

not an illusion, the air is colder

No, it is not.

If you compress a gas, it gains heat, it does not lose it.

That probably isn't the best way to phrase it, but if we keep it in this context.. you know what I mean.

 

[Howard]

Originally posted by: LongCoolMother
wind causes moisture (sweat molecules) to evaporate. the change from liquid to gas takes energy, most of which comes from the heat on your skin.

No such thing as sweat molecules.

 

[Howard]

Originally posted by: Eli

Originally posted by: HardcoreRobot

Originally posted by: Eli

Originally posted by: HardcoreRobot
in a related note, if you are trying to cool yourself off by blowing air on yourself, make your mouth as narrow as possible. forcing the air through a smaller hole takes the heat out of the air. you can try it on your hand, if your mouth is open wide it is hot and sticky

also, i love this quote "friction causes the cold" hahahahahahahaha

Compression causes heat; squeezing air through a smaller hole would not cause it to lose heat.

It would increase the pressure though, possibly causing the illusion it is cooler, due to things already mentioned in this thread.

not an illusion, the air is colder

No, it is not.

If you compress a gas, it gains heat, it does not lose it.

That probably isn't the best way to phrase it, but if we keep it in this context.. you know what I mean.

I agree. If you compress a gas, the temperature will go up.

When you create a smaller aperture with your lips, the velocity of the air increases and evaporates water quicker. The faster the water on your skin evaporates, the cooler it feels.

 

[BD2003]

Its mostly evaporative cooling.

But dont forget to take into account that the vast majority of the time, air temp is lower than body temp (98.7), and the convection speeds up the cooling process.