On Sunday, January 5, 2014 3:41:27 PM UTC-5, Ed Pawlowski wrote:
On 1/5/2014 9:41 AM, wrote:







Rate of heat transfer is the only



difference, the temperature never goes below ambient.





I agree and never suggested otherwise. Note that rate of heat transfer

is an effect on inanimate objects.





Yes, but that is an efect of the wind, not the wind chill the weatherman

talks about how we feel in the wind.


The reported windchill is directly dependent on the wind.
Let's say the weatherman was giving his report and you missed
what he said about the wind. Let's look at two different
reports:

A - It's currently 35F and it's going to drop to 20F overnight
with a windchill of 20F.

B - It's currently 35F and it's going to drop to 20F overnight
with a windchill of 0F.

You have a drafty crawlspace or an unheated cabin. Would you
think there is more reason to be concerned about pipes freezing
overnight in case A or B?





















The big difference is how well sealed the house is. Radiational cooling



difference will be minimal, but convection can be considerable.



Which shows that windchill applies to inanimate objects too.





No, it shows the effects of wind but has nothing to do with the

windchill factor on the 11 o'clock news

BS. The windchill is directly dependent on windspeed. It can
be used as a proxy for windspeed. If the forecasted temp is
20F and the windchill is also 20F, what does that tell you about
the wind?: no wind. If it's forecsted to be 20F with a windchill
of 0F, that tells you there is going to be a strong wind and you
should be more concerned about pipes freezing in a draft crawspace,
unheated cabin, etc.