The technical side of green building....

One of the magazines I have been following for the past month has been the Journal of Light Construction, on loan from Professor Bennett. There is an interesting article titled, "Blower Door Testing"! Very Exciting. I actually found out though that air leakage accounts for 30 to 50 percent of the heat loss in some homes. So to analyze this there is a contraption that gets mounted in a doorway and exagerrates air leaks allowing a skilled technician to find the leaks. I learned about some ways of measuring this air leakage through CFM and ACH. ACH is air flow changes per hour, with homes maintaining 5-6 ACH per hour at 50 Pa (pascals) pressure considered "tight" and those over 20 ACH per hour being "loose." Very riveting. CFM or cubic feet per minute is sometimes a better measure to use because ACH might make a small space seem "leaky" and a large space "tight" just by the nature of the spatce volume. CFM is also easily obtained through single point tests. (Where they measure the air in one location) The article goes on describing the specific steps in the measurement process, which involves turning off certain building systems, etc. I think this magazine provides a good technical contrast to articles that describe things in a more general manner. I recommend taking a look at this magazine! Come find me to see it.
-Nick