From: r_delaney2001@yahoo.com   
      
   A nearby college includes a building, surrounded by an   
   outdoor arcade, at street level.  At one point, the warm   
   internal air is expelled, which is natural, they perform   
   continuous circulation.  A nice spot, on a cold night!   
      
   However, I wonder, is there any hazard in breathing that air?   
   Is it chemically processed somehow, contaminated?   
      
   And, isn't it inefficient?  The outgoing air ought to   
   pass through a heat exchanger, to warm the incoming air.   
   Isn't that wasted energy?   
      
   --   
   Rich   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)