There are several modes of cooling by motion of air molecules over a surface -without the need for evaporation.
For example, on a molecular level, all air within a given volume over, say Nevada, is at the same temperature of 90*. This means that all the molecules bouncing around in random directions collectively have an AVERAGE temperature of 90*. The molecular speeds are actually very fast and taken together have a skewed bell curve look. It is the speed of the molecules alone that determines the temperature! If a wind blows, the random directions of the molecules have a new resultant direction in the direction of the wind. This new vector has on average a much lower speed than the other random directions that the molecules are shooting off in. Given a test subject also at the ambient temp of 90* within the path of the wind (and this new vector), the molecules extract energy from the object in the direction of the new vector (i.e. wind). This extraction of energy is cooling the object.
In another application of this same principle, think what happens to supersonic jet planes. The speed at which they strike molecules -no matter what temperature they're at because they can only cool at sonic or subsonic speeds- will heat up the normal surface (the flying edge) of the plane.
Hope this clears it up. (yes, I'm a physicist.)
Sevak
On Mon, 2003-11-17 at 11:53, John Banes wrote:
I think you guys are mixing up cooling and chill factor. Chill factor is the result of moisture evaporation lowering the surface temperature below ambient temperature. In humans we always have moisture on our skin so the wind causes it to evaporate faster lowering the temperature below the actual air temperature. I would guess that on a rainy day your wet radio might also have a chill factor, but if it is dry there is no evaporation therefore no chill factor. No matter how much wind there is it can't be colder than the air temperature. John ----- Original Message ----- From: "Dimitrios Sidiropoulos" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Monday, November 17, 2003 7:50 AM Subject: Re: [smartBridges] Airpoint gone mad and turned into AB > Eje, > > Do not forget that the unit radiates heat at all times. > If it is 10*F and no wind the temp inside the unit will be 10+. > If there is wind (still at 10F) it will absorbe more heat from the unit and it will > lower it's temp closer to the 10F. > > If you test the specs of a unit at -40F inside a freezer then the temp inside the > unit will higher then -40 (lets say -38) if there is wind at -40 then the temp > inside the unit is closer to -40 (although still not -40)The faster the wind blows > the closer it gets the ratior temp to the real temperature. > > So yes!! Wind does affect the temperature of the radiator all though it has no > effect on the radiating ellement, etc. > > Thank you > Dimitri > > http://www.vernet.gr > The PART-15.ORG smartBridges Discussion List > To Join: mailto:[EMAIL PROTECTED] (in the body type subscribe smartBridges <yournickname> > To Remove: mailto:[EMAIL PROTECTED] (in the body type unsubscribe smartBridges) > Archives: http://archives.part-15.org > The PART-15.ORG smartBridges Discussion List To Join: mailto:[EMAIL PROTECTED] (in the body type subscribe smartBridges <yournickname> To Remove: mailto:[EMAIL PROTECTED] (in the body type unsubscribe smartBridges) Archives: http://archives.part-15.org
