Wind chill: how to calculate? Is there such thing as wind warmth ?

  • Thread starter pa5tabear
  • Start date
  • Tags
    Wind
In summary, the conversation discusses the concepts of wind chill and wind warmth and their effects on the body. It is mentioned that wind warmth can be felt if not sweating profusely and that wind chill is only applicable in cold weather with dry skin. The topic of wet bulb temperature is also brought up as a measure of the effects of wind and humidity on the body. The conversation also mentions the use of wind heating in convection ovens and the existence of the heat index as a measure of temperature perception.
  • #1
pa5tabear
175
0
Wind chill: how to calculate? Is there such thing as wind "warmth"?

If it is really hot outside, and the air were warmer than your skin, would you feel warmer when it blows on you? Would there still be some sort of chilling effecT?

I'm guessing it's like basic convection. If the the fluid is warmer, the fluit will transfer heat to the body, and you will end up with some heating.
 
Physics news on Phys.org
  • #2


I think the coolness you feel is just not described by convection. Evaporation of water from your skin also plays a major role in the temperature you perceive of air around you. The loss of heat through evaporation and gain/loss due to conduction together decide whether wind is cool or warm. So in principle, yes, you can feel wind "warmth". But only if you are not sweating profusely at that moment.
 
  • #3


Almost. Because of evaporation, our bodies' ability to cool itself comes largely from sweat. So cooling amount is based on wind and wet bulb temperature. Wet bulb temp is based on dry bulb (normal) temp and humidity. There are no natural environments where wet bulb temp is high enough to cause a "wind heating" effect, so such a term does not exist. Even on a 110F day in Phoenix, your body can still cool itself -- better than on a 95F day in Philadelphia.
 
Last edited:
  • #4


But 'wind chill' doesn't only refer to evaporative cooling, surely(?). It must also involve wind speed (forced convection effects) against a dry clothed body.
Isn't it "wind warmth" inside a fan oven?
 
  • #5


Wind chill doesn't include evaporative cooling at all...or clothes, for that matter. Wind chill is defined only for cold weather, when your skin is essentially dry. The nearest analogue for hot weather is Wet Bulb Globe Temperature (not the same as wet bulb temperature), which uses a formula to estimate the effects of ambient sunlight and wind on a wet bulb (you, in a sweaty tshirt) on a hot day.

Yes, wind heating is what happens in a convection oven.

Fyi, wind chill and WBGT both have good wiki pages.
 
  • #6


Also, "heat index" (is one I don't like because it is purely subjective) tries to equate what it feels like on a dry vs a humid day.
 

1. What is wind chill and why is it important to calculate?

Wind chill is the perceived decrease in air temperature felt by the body when exposed to wind. It is important to calculate because it helps us understand how cold it actually feels outside and can help us prepare for potentially dangerous conditions.

2. How is wind chill calculated?

Wind chill is calculated using a mathematical formula that takes into account the air temperature and wind speed. The formula was developed through a series of experiments that measured how quickly water froze at different air temperatures and wind speeds.

3. Can wind chill make the temperature feel warmer?

No, wind chill does not actually make the temperature feel warmer. It is simply a perception of how cold it feels based on the combination of air temperature and wind speed. Wind chill cannot increase the actual temperature.

4. Is there such thing as "wind warmth"?

No, there is no such thing as "wind warmth". Wind can only make the air feel colder, not warmer. However, on a hot day, a light breeze can help evaporate sweat and cool the body, making it feel more comfortable.

5. How accurate is the wind chill calculation?

The wind chill calculation is fairly accurate in determining how cold it feels outside. However, it does not take into account other factors such as humidity, which can also affect how cold it feels. Additionally, personal factors such as clothing and body composition can also impact an individual's perception of wind chill.

Similar threads

Replies
4
Views
568
Replies
1
Views
2K
  • Introductory Physics Homework Help
2
Replies
39
Views
2K
  • STEM Academic Advising
Replies
2
Views
800
  • Classical Physics
Replies
6
Views
1K
Replies
10
Views
393
Replies
69
Views
10K
Replies
20
Views
1K
Replies
5
Views
252
Back
Top