by Mike
(Virginia)
The Y in the PVC is for the crawl space, which wasn't needed.
My basement is 2200 sq.ft. of concrete, plus a 200 sq. ft. gravel covered crawl space. The crawl space has very little head room, and would have been extremely difficult to mitigate. Val answered several questions,during the project, but the most helpful advice he gave me, was to "take care of the concrete floor first, and then retest, before working on the crawl space." He said that often,doing the concrete area alone was adequate,and that turned out to be true in my case. My levels went from 16 to less than 1 on the retest. His advice saved me a huge amount of work. Plus, I found his fan prices to be very competitive.