On Friday, January 3, 2014 7:47:37 PM UTC-5, Gordon Shumway wrote:
On Fri, 03 Jan 2014 17:40:35 -0600, philo� wrote:



On 01/03/2014 05:21 PM, Gordon Shumway wrote:

On Fri, 03 Jan 2014 16:11:35 -0500, Stormin Mormon

wrote:



Tonight in NYS supposed to be 0F, and wind

chill -10 or so. Which number is the one

which concerns water pipes freezing?



I know the pipes won't get below the actual

temp, but are they more likely to freeze,

with wind?



Wind chill is the effect the combination of cold air and wind has on

exposed flesh relative to only cold air. "Wind chill" has absolutely

no effect on inanimate objects. The wind on an inanimate object will

cool an inanimate object to the ambient temperature quicker than no

wind. It is impossible to get an inanimate object colder than ambient

temperature by using wind that is also ambient temperature.



Now, don't ever ask that question again or I'll turn this car

around...









That's absolutely correct but trader4 made a valid point.





Air in a wall would be warmed by the house and if no outside air got in

would act to keep the pipe warm. With a strong wind blowing, any warm

air trapped in the wall would be dissipated pretty fast.



What I said is completely true, period.

Actually you contradicted yourself:

" "Wind chill" has absolutely
no effect on inanimate objects. The wind on an inanimate object will
cool an inanimate object to the ambient temperature quicker than no
wind."

Wind chill is a measure of the how wind causes people to feel
colder. It also has a similar effect on cooling inanimate objects
that are warmer than ambient. Therefore it can have an effect on
objects that are warmer than ambient.

Will a pail of water at 75F freeze faster if you put it
outside where it's exposed when it's 20F with a windchill of 17F or
a winchill of 5F?



What the temperature in the

wall that contains the plumbing is, or will become, whether it's

insulated well or not at all, is the ambient temperature, period.



Only if you define ambient temperature as the temperature at the
pipe. If by ambient you mean the outside temperature, then the
temperature in the wall is likely to be lower with a wind blowing
on it than without.



Granted, plumbing in an outside wall that is poorly insulated will

have a greater chance of freezing at a given outside temperature when

it's windy than not but that's what was contained in my statement.



Wind is a component of wind chill. Would you not be more concerned
about pipes freezing on a day when the wind chill is 0F than when
it was 17F, even if the outside temp both days was 20F?