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 windchill number reflects the increased heat transfer that
wind causes. The only two component are temp and wind speed.
Do you disagree that water pipes are more likely to freeze in
a crawlspace, a house with no heat, etc on a night when the windchill
is 0F, instead of 20F, even when the actual overnight temp is 20F on both
nights?
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
If it has nothing to do with the reported windchill, then you're
answer to the above question is that it makes no difference?
The pipes are just as likely to freeze in that crawlspace on a
night when the windchill is 0F, as they are when the windchill is
20F, even though the outside air is 20F, both nights?
Here, from the Weather Channel:
http://www.weather.com/activities/ho...e_prevent.html
"Pipes in attics, crawl spaces and outside walls are all vulnerable to freezing, especially if there are cracks or openings that allow cold, outside air to flow across the pipes. Research at the University of Illinois has shown that €śwind chill,€ť the cooling effect of air and wind that causes the human body to lose heat, can play a major role in accelerating ice blockage, and thus bursting, in water pipes. "
From City of Rochester:
http://www.rochesternh.net/public_Do...ER%20PIPES.pdf
"Pipes inside or outside walls, or in an enclosed area can freeze,
especially when the wind-chill factor is well below zero and heat is
not circulating in those areas."