Wind Chill..wind proof ...

Am I correct in thinking that wind chill factor is not in relation to inanimate objects?

I understand that if something is listed as a wind chill of -50 I best keep any skin well covered. Therefore if I put on truly windproof clothing do I then return to dealing with the real temp and not the "Chill Factor" ?

Some clothing is listed as wind proof & some as wind resistent . If, for example, I am camping and I have stored the two styles shirts out in the wind. In the morning I reach for one of them ...are they the same temp?

Are food and water affected ?
If it is 35 degrees out with 30 mph winds bringing the wind chill temp to 5 degrees..is my water frozen or not ?

Will it warm up if I take it out of the wind ??

Thanks... inquiring minds would like to know

spider solo said:

A. Am I correct in thinking that wind chill factor is not in relation to inanimate objects?

B. I understand that if something is listed as a wind chill of -50 I best keep any skin well covered. Therefore if I put on truly windproof clothing do I then return to dealing with the real temp and not the "Chill Factor" ?

C. Some clothing is listed as wind proof & some as wind resistent . If, for example, I am camping and I have stored the two styles shirts out in the wind. In the morning I reach for one of them ...are they the same temp?

D. Are food and water affected ? If it is 35 degrees out with 30 mph winds bringing the wind chill temp to 5 degrees..is my water frozen or not ?

E. Will it warm up if I take it out of the wind ??

Click to expand...

A. You are correct.

B. The wind will still be pushing you around, but you will feel warmer. Imagine you were surrounded by a wind proof tent, or even a house. You are not going to feel the wind chill if you can get it away from your body. However, for something to be truly windproof, it might have to be thicker than a coat.

C. Yes

D. Your water will not freeze, but it will evaporate faster than if it were calm.

E. As you probably already guessed, No.

The wind speeds up the rate of heat loss. You will not feel the wind chill effect as much with windproof clothing. But, heat from your body will be to able to get thru it and then taken away by the air.

spider solo said:

Am I correct in thinking that wind chill factor is not in relation to inanimate objects?

Click to expand...

Yes.

Wind chill is the still air temp that gives the same rate of heat loss on exposed skin as the real temp plus wind.

I understand that if something is listed as a wind chill of -50 I best keep any skin well covered. Therefore if I put on truly windproof clothing do I then return to dealing with the real temp and not the "Chill Factor" ?

Click to expand...

Actually just a bit below the real temp because the wind will remove heat faster from the surface of the truly windproof clothing than will still air.

For realistic (ie leaky) windproof clothing, the effective temp will be somewhere between the real and windchill temps.

Some clothing is listed as wind proof & some as wind resistent . If, for example, I am camping and I have stored the two styles shirts out in the wind. In the morning I reach for one of them ...are they the same temp?

Click to expand...

Yes--the real temp.

Are food and water affected ?
If it is 35 degrees out with 30 mph winds bringing the wind chill temp to 5 degrees..is my water frozen or not ?

Click to expand...

The conductive heat loss (or gain) will move your food and water toward 35 deg. But the winds will increase the water evaporation rate. Evaporation removes heat, so the food and water will actually be a bit below 35. In theory, the evaporative cooling could freeze your food and water, but in practice it isn't very likely.

Will it warm up if I take it out of the wind ??

Click to expand...

The evaporative heat loss has been removed, so it will warm up the bit up to 35 deg.

Thanks... inquiring minds would like to know

[soapbox on]
Windchill is very different from real temps. Functioning at -40 windchill and functioning at a real temp of -40 are very different. The wind from just walking at a real temp of -40 is very dangerous.

I wouldn't be unhappy to see windchill banned... (in Boston and everywhere else )
[soapbox off]

Doug

Tom Rankin said:

B. The wind will still be pushing you around, but you will feel warmer. Imagine you were surrounded by a wind proof tent, or even a house. You are not going to feel the wind chill if you can get it away from your body. However, for something to be truly windproof, it might have to be thicker than a coat.

Click to expand...

In a house it is impossible, for all practical puposes, to completely protect against increased heat loss related to high winds. Although you don't necessarily feel a draft, the windward side is subject to infiltration and the leeward side subject to a vacuum. Both contribute to heat loss in high winds as compared to calm days, given the same temperature. There are other dynamics going on too boring to contemplate but contributing to the same result.

Our outerwear is even more penetrable than our homes ... well, most homes ... mine was built in 1845 ... so, don't expect to feel very much more cozy comfy in windproof shells. The best antidote I know for wind chill is cover up and keep moving.

DougPaul said:

[soapbox on]I wouldn't be unhappy to see windchill banned... (in Boston and everywhere else )
[soapbox off]

Click to expand...

Doug, any room on that soapbox for me?

I grew up (well, kinda) before the days of windchill, in a place where the real temps did get to -40 and -45 on still January nights. Ironic thing is that with any wind, the coldest air at the bottom of the valley mixed with the warmer air a little higher and it actually warmed up a tiny bit. Not a real inversion, but just the effect of that dense, cold air sinking to the bottom and flowing down the river valley like the fluid that it is.

As far as I can tell, the major purpose of windchill ratings is to scare people into reasonable preparation for cold weather!