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Vic Smith Vic Smith is offline
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Default Wind chill and water pipes

On Sun, 05 Jan 2014 15:14:51 -0500, Ed Pawlowski wrote:

On 1/5/2014 9:24 AM, wrote:


Nonsense. Why would windchill only remove heat from things that are alive?
Good grief.


I think we are confusing definitions. When the weatherman give wind
chill or "real feel" temperatures he is talking about how exposed human
flesh feels the temperature. Think evaporative cooling.

Drop the word "chill" and I think we can all agree that wind removes
heat faster. There is no evaporative cooling, but faster movement of
heat energy from the object.

No matter how you term things, it does not change the laws of physics. .


Exactly.

http://www.nws.noaa.gov/os/windchill/index.shtml
"The NWS Windchill Temperature (WCT) index uses advances in science,
technology, and computer modeling to provide an accurate,
understandable, and useful formula for calculating the dangers from
winter winds and freezing temperatures. The index:
€˘Calculates wind speed at an average height of five feet, typical
height of an adult human face, based on readings from the national
standard height of 33 feet, typical height of an anemometer
€˘Is based on a human face model
€˘Incorporates heat transfer theory, heat loss from the body to its
surroundings, during cold and breezy/windy days
€˘Lowers the calm wind threshold to 3 mph
€˘Uses a consistent standard for skin tissue resistance
€˘Assumes no impact from the sun (i.e., clear night sky)."

So the term "windchill" has been "appropriated" by the NWS for
application to human skin.
If you want to use it for pipes in an accurate manner, you need to
specify type of pipe, heat transfer rate, etc.
I'm sure it has been done by engineers who design things where it's
relevent. But they don't call it "windchill."