Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: thedoc on 19/01/2010 19:06:02

Title: Why are my windows drafty?
Post by: thedoc on 19/01/2010 19:06:02

Why are my windows so drafty?  My understanding of the second law of thermodynamics is that heat moves from a hot body to a cold one.  So, can you explain to me why cold air is flowing into my very nice warm room through a gap in a badly fitted window?  I’ve proved that cold air is moving in this direction by placing some soft tissue paper in the gap.
Asked by Martin Taylor

               
               Read the naked scientists answer here (http://www.thenakedscientists.com/HTML/content/questions/question/2529/)
               
            

Title: Why are my windows drafty?
Post by: Don_1 on 13/01/2010 12:09:28

I can think of two explanations.

First, there is an opposing crack out of which warm air is escaping.

Second, the external pressure, created by heavier, denser cold air coupled with the effects of the wind, is greater than the internal pressure of the lighter and less dense warm air.

Title: Why are my windows drafty?
Post by: glovesforfoxes on 13/01/2010 14:59:51

Can't the heat just be transferred to the colder body if the two gases come into contact?

Title: Why are my windows drafty?
Post by: thedoc on 19/01/2010 19:06:02

Listen to the answer to this question on our podcast. (http://www.thenakedscientists.com/HTML/podcasts/show/2010.01.17/)