This topic has already been discussed on EcoRenovator..
Link to a Build It Solar project, where Gary
actually built a homemade blower door, rather than talk about it.
He also included pictures to prove his legandary moxie.
Gary's site is really excellent. It is teeming with projects illustrated and described so that a reader can actually duplicate the results.
I'm afraid EcoRenovator is becoming a talking shop.
Best,
-AC