Why is our breath, which is warm when we breathe, cool when blown out?

hooting our hands in the cold we try to warm or by blowing when we burn something we try to cool has been. So how does this difference occur?

Actually The air that comes out of our mouth is usually at the same temperature. Since the temperature of the air coming out of our mouths does not change much, there is another reason behind this. We have compiled these reasons for you.

First of all, the main reason for this situation is mouth movement.

Well ‘when you say ‘hoh’ the mouth cavity is bigger Because the air flow from the lungs and out, the flow rate will be lower. So its speed is even slower; naturally, when the speed is slow, the heated air in the lungs gets even hotter until it comes out of the mouth.

While blowing or while puffing, the oral cavity is narrower. Therefore, the flow rate of the flowing air is fast. Contrary to the other E, the air will flow quickly on the path from the lungs to the mouth, so it is thrown out without heating.

If you ask what is the flow rate of the air; It is the amount of fluid passing through a certain area per unit time. So what’s actually mentioned is the air flow rate.

When you blow through pursed lips (as when whistling), you create a fast-moving stream of air.

When fast moving air (your breath) is released into relatively still air (the air around you) creates turbulence.

The effect of turbulence is that it pushes the surrounding stagnant air out of your mouth into the air. Just like in the photo above. The blue arrows show the air surrounding you, and the black arrow the air coming out of your mouth. The air outside our bodies is always slightly cooler than the air coming out of our lungs.

The air that reaches your hand is cold, as the colder air from the surrounding is drawn into the warmer airflow that exits our mouth. In fact, from pursed lips Most of the air you feel in your palms as you blow is the surrounding air.

When you blow from a wider mouth like in the photo above, as when you say ‘haah’, air exits at a slower rate. Because of this, it doesn’t create the same turbulence as faster airflow and, accordingly, draws much less volume of surrounding colder air into your warmer breath.

In addition, this situation is what we are blowing It also has to do with its proximity to our mouth. For example, when blowing, bring your hand as close to your mouth as possible; The air coming out will be hot, and when you move it away, it will cool.