On Mar 30, 7:43*am, "Wild_Bill" wrote:
...
Leakage and air infiltration of windows are significant factors in energy
usage, or more accurately as energy wasting.

Air infiltration is a compromise between energy loss and "proper"
ventilation:
http://www.engineeringtoolbox.com/ai...oom-d_867.html

Like police vs fire recommendations for ease of access they conflict
wildly.

jsw